Reenable the hardened runtime for macOS.

Corrects buffer placement of decoded sectors.

Analyser/Machines.hpp

@@ -19,6 +19,7 @@ enum class Machine {
 	AtariST,
 	ColecoVision,
 	Electron,
+	Enterprise,
 	Macintosh,
 	MasterSystem,
 	MSX,

Analyser/Static/Enterprise/StaticAnalyser.cpp

@@ -0,0 +1,81 @@
+//
+//  StaticAnalyser.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 24/06/2021.
+//  Copyright 2021 Thomas Harte. All rights reserved.
+//
+
+#include "StaticAnalyser.hpp"
+#include "Target.hpp"
+
+#include "../../../Storage/Disk/Parsers/FAT.hpp"
+
+#include <algorithm>
+
+namespace {
+
+bool insensitive_equal(const std::string &lhs, const std::string &rhs) {
+	return std::equal(
+		lhs.begin(), lhs.end(),
+		rhs.begin(), rhs.end(),
+		[] (char l, char r) {
+			return tolower(l) == tolower(r);
+	});
+}
+
+}
+
+Analyser::Static::TargetList Analyser::Static::Enterprise::GetTargets(const Media &media, const std::string &, TargetPlatform::IntType) {
+	// This analyser can comprehend disks only.
+	if(media.disks.empty()) return {};
+
+	// Otherwise, assume a return will happen.
+	Analyser::Static::TargetList targets;
+	using Target = Analyser::Static::Enterprise::Target;
+	auto *const target = new Target;
+	target->media = media;
+
+	// Always require a BASIC.
+	target->basic_version = Target::BASICVersion::Any;
+
+	// Inspect any supplied disks.
+	if(!media.disks.empty()) {
+		// DOS will be needed.
+		target->dos = Target::DOS::EXDOS;
+
+		// Grab the volume information, which includes the root directory.
+		auto volume = Storage::Disk::FAT::GetVolume(media.disks.front());
+		if(volume) {
+			// If there's an EXDOS.INI then this disk should be able to boot itself.
+			// If not but if there's only one .COM or .BAS, automatically load that.
+			// Failing that, issue a :DIR and give the user a clue as to how to load.
+			const Storage::Disk::FAT::File *selected_file = nullptr;
+			bool has_exdos_ini = false;
+			bool did_pick_file = false;
+			for(const auto &file: (*volume).root_directory) {
+				if(insensitive_equal(file.name, "exdos") && insensitive_equal(file.extension, "ini")) {
+					has_exdos_ini = true;
+					break;
+				}
+
+				if(insensitive_equal(file.extension, "com") || insensitive_equal(file.extension, "bas")) {
+					did_pick_file = !selected_file;
+					selected_file = &file;
+				}
+			}
+
+			if(!has_exdos_ini) {
+				if(did_pick_file) {
+					target->loading_command = std::string("run \"") + selected_file->name + "." + selected_file->extension + "\"";
+				} else {
+					target->loading_command = ":dir\n";
+				}
+			}
+		}
+	}
+
+	targets.push_back(std::unique_ptr<Analyser::Static::Target>(target));
+
+	return targets;
+}

Analyser/Static/Enterprise/StaticAnalyser.hpp

@@ -0,0 +1,27 @@
+//
+//  StaticAnalyser.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 24/06/2021.
+//  Copyright 2018 Thomas Harte. All rights reserved.
+//
+
+#ifndef Analyser_Static_Enterprise_StaticAnalyser_hpp
+#define Analyser_Static_Enterprise_StaticAnalyser_hpp
+
+#include "../StaticAnalyser.hpp"
+#include "../../../Storage/TargetPlatforms.hpp"
+#include <string>
+
+namespace Analyser {
+namespace Static {
+namespace Enterprise {
+
+TargetList GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms);
+
+}
+}
+}
+
+
+#endif /* Analyser_Static_Enterprise_StaticAnalyser_hpp */

Analyser/Static/Enterprise/Target.hpp

@@ -0,0 +1,53 @@
+//
+//  Target.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 14/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#ifndef Analyser_Static_Enterprise_Target_h
+#define Analyser_Static_Enterprise_Target_h
+
+#include "../../../Reflection/Enum.hpp"
+#include "../../../Reflection/Struct.hpp"
+#include "../StaticAnalyser.hpp"
+
+#include <string>
+
+namespace Analyser {
+namespace Static {
+namespace Enterprise {
+
+struct Target: public Analyser::Static::Target, public Reflection::StructImpl<Target> {
+	ReflectableEnum(Model, Enterprise64, Enterprise128, Enterprise256);
+	ReflectableEnum(EXOSVersion, v10, v20, v21, v23, Any);
+	ReflectableEnum(BASICVersion, v10, v11, v21, Any, None);
+	ReflectableEnum(DOS, EXDOS, None);
+
+	Model model = Model::Enterprise128;
+	EXOSVersion exos_version = EXOSVersion::Any;
+	BASICVersion basic_version = BASICVersion::None;
+	DOS dos = DOS::None;
+	std::string loading_command;
+
+	Target() : Analyser::Static::Target(Machine::Enterprise) {
+		if(needs_declare()) {
+			AnnounceEnum(Model);
+			AnnounceEnum(EXOSVersion);
+			AnnounceEnum(BASICVersion);
+			AnnounceEnum(DOS);
+
+			DeclareField(model);
+			DeclareField(exos_version);
+			DeclareField(basic_version);
+			DeclareField(dos);
+		}
+	}
+};
+
+}
+}
+}
+
+#endif /* Analyser_Static_Enterprise_Target_h */

Analyser/Static/StaticAnalyser.cpp

@@ -23,6 +23,7 @@
 #include "Coleco/StaticAnalyser.hpp"
 #include "Commodore/StaticAnalyser.hpp"
 #include "DiskII/StaticAnalyser.hpp"
+#include "Enterprise/StaticAnalyser.hpp"
 #include "Macintosh/StaticAnalyser.hpp"
 #include "MSX/StaticAnalyser.hpp"
 #include "Oric/StaticAnalyser.hpp"
@@ -43,9 +44,9 @@
 #include "../../Storage/Disk/DiskImage/Formats/MacintoshIMG.hpp"
 #include "../../Storage/Disk/DiskImage/Formats/G64.hpp"
 #include "../../Storage/Disk/DiskImage/Formats/DMK.hpp"
+#include "../../Storage/Disk/DiskImage/Formats/FAT12.hpp"
 #include "../../Storage/Disk/DiskImage/Formats/HFE.hpp"
 #include "../../Storage/Disk/DiskImage/Formats/MSA.hpp"
-#include "../../Storage/Disk/DiskImage/Formats/MSXDSK.hpp"
 #include "../../Storage/Disk/DiskImage/Formats/NIB.hpp"
 #include "../../Storage/Disk/DiskImage/Formats/OricMFMDSK.hpp"
 #include "../../Storage/Disk/DiskImage/Formats/SSD.hpp"
@@ -55,8 +56,14 @@
 
 // Mass Storage Devices (i.e. usually, hard disks)
 #include "../../Storage/MassStorage/Formats/DAT.hpp"
+#include "../../Storage/MassStorage/Formats/DSK.hpp"
 #include "../../Storage/MassStorage/Formats/HFV.hpp"
 
+// State Snapshots
+#include "../../Storage/State/SNA.hpp"
+#include "../../Storage/State/SZX.hpp"
+#include "../../Storage/State/Z80.hpp"
+
 // Tapes
 #include "../../Storage/Tape/Formats/CAS.hpp"
 #include "../../Storage/Tape/Formats/CommodoreTAP.hpp"
@@ -73,15 +80,23 @@
 
 using namespace Analyser::Static;
 
-static Media GetMediaAndPlatforms(const std::string &file_name, TargetPlatform::IntType &potential_platforms) {
-	Media result;
+namespace {
 
+std::string get_extension(const std::string &name) {
 	// Get the extension, if any; it will be assumed that extensions are reliable, so an extension is a broad-phase
 	// test as to file format.
-	std::string::size_type final_dot = file_name.find_last_of(".");
-	if(final_dot == std::string::npos) return result;
-	std::string extension = file_name.substr(final_dot + 1);
+	std::string::size_type final_dot = name.find_last_of(".");
+	if(final_dot == std::string::npos) return name;
+	std::string extension = name.substr(final_dot + 1);
 	std::transform(extension.begin(), extension.end(), extension.begin(), ::tolower);
+	return extension;
+}
+
+}
+
+static Media GetMediaAndPlatforms(const std::string &file_name, TargetPlatform::IntType &potential_platforms) {
+	Media result;
+	const std::string extension = get_extension(file_name);
 
 #define InsertInstance(list, instance, platforms) \
 	list.emplace_back(instance);\
@@ -131,8 +146,9 @@ static Media GetMediaAndPlatforms(const std::string &file_name, TargetPlatform::
 			TargetPlatform::AmstradCPC | TargetPlatform::Oric | TargetPlatform::ZXSpectrum)						// DSK (Amstrad CPC, etc)
 	Format("dsk", result.disks, Disk::DiskImageHolder<Storage::Disk::AppleDSK>, TargetPlatform::DiskII)			// DSK (Apple II)
 	Format("dsk", result.disks, Disk::DiskImageHolder<Storage::Disk::MacintoshIMG>, TargetPlatform::Macintosh)	// DSK (Macintosh, floppy disk)
-	Format("dsk", result.mass_storage_devices, MassStorage::HFV, TargetPlatform::Macintosh)						// DSK (Macintosh, hard disk)
-	Format("dsk", result.disks, Disk::DiskImageHolder<Storage::Disk::MSXDSK>, TargetPlatform::MSX)				// DSK (MSX)
+	Format("dsk", result.mass_storage_devices, MassStorage::HFV, TargetPlatform::Macintosh)						// DSK (Macintosh, hard disk, single volume image)
+	Format("dsk", result.mass_storage_devices, MassStorage::DSK, TargetPlatform::Macintosh)						// DSK (Macintosh, hard disk, full device image)
+	Format("dsk", result.disks, Disk::DiskImageHolder<Storage::Disk::FAT12>, TargetPlatform::MSX)				// DSK (MSX)
 	Format("dsk", result.disks, Disk::DiskImageHolder<Storage::Disk::OricMFMDSK>, TargetPlatform::Oric)			// DSK (Oric)
 	Format("g64", result.disks, Disk::DiskImageHolder<Storage::Disk::G64>, TargetPlatform::Commodore)			// G64
 	Format(	"hfe",
@@ -142,6 +158,7 @@ static Media GetMediaAndPlatforms(const std::string &file_name, TargetPlatform::
 			// HFE (TODO: switch to AllDisk once the MSX stops being so greedy)
 	Format("img", result.disks, Disk::DiskImageHolder<Storage::Disk::MacintoshIMG>, TargetPlatform::Macintosh)		// IMG (DiskCopy 4.2)
 	Format("image", result.disks, Disk::DiskImageHolder<Storage::Disk::MacintoshIMG>, TargetPlatform::Macintosh)	// IMG (DiskCopy 4.2)
+	Format("img", result.disks, Disk::DiskImageHolder<Storage::Disk::FAT12>, TargetPlatform::Enterprise)		// IMG (Enterprise/MS-DOS style)
 	Format("msa", result.disks, Disk::DiskImageHolder<Storage::Disk::MSA>, TargetPlatform::AtariST)				// MSA
 	Format("nib", result.disks, Disk::DiskImageHolder<Storage::Disk::NIB>, TargetPlatform::DiskII)				// NIB
 	Format("o", result.tapes, Tape::ZX80O81P, TargetPlatform::ZX8081)											// O
@@ -199,14 +216,35 @@ Media Analyser::Static::GetMedia(const std::string &file_name) {
 
 TargetList Analyser::Static::GetTargets(const std::string &file_name) {
 	TargetList targets;
+	const std::string extension = get_extension(file_name);
 
+	// Check whether the file directly identifies a target; if so then just return that.
+#define Format(ext, class) 											\
+	if(extension == ext)	{										\
+		try {														\
+			auto target = Storage::State::class::load(file_name);	\
+			if(target) {											\
+				targets.push_back(std::move(target));				\
+				return targets;										\
+			}														\
+		} catch(...) {}												\
+	}
+
+	Format("sna", SNA);
+	Format("szx", SZX);
+	Format("z80", Z80);
+
+#undef TryInsert
+
+	// Otherwise:
+	//
 	// Collect all disks, tapes ROMs, etc as can be extrapolated from this file, forming the
 	// union of all platforms this file might be a target for.
 	TargetPlatform::IntType potential_platforms = 0;
 	Media media = GetMediaAndPlatforms(file_name, potential_platforms);
 
-	// Hand off to platform-specific determination of whether these things are actually compatible and,
-	// if so, how to load them.
+	// Hand off to platform-specific determination of whether these
+	// things are actually compatible and, if so, how to load them.
 #define Append(x) if(potential_platforms & TargetPlatform::x) {\
 	auto new_targets = x::GetTargets(media, file_name, potential_platforms);\
 	std::move(new_targets.begin(), new_targets.end(), std::back_inserter(targets));\
@@ -220,6 +258,7 @@ TargetList Analyser::Static::GetTargets(const std::string &file_name) {
 	Append(Coleco);
 	Append(Commodore);
 	Append(DiskII);
+	Append(Enterprise);
 	Append(Macintosh);
 	Append(MSX);
 	Append(Oric);

Analyser/Static/StaticAnalyser.hpp

@@ -15,6 +15,7 @@
 #include "../../Storage/Disk/Disk.hpp"
 #include "../../Storage/MassStorage/MassStorageDevice.hpp"
 #include "../../Storage/Tape/Tape.hpp"
+#include "../../Reflection/Struct.hpp"
 
 #include <memory>
 #include <string>
@@ -23,8 +24,10 @@
 namespace Analyser {
 namespace Static {
 
+struct State;
+
 /*!
-	A list of disks, tapes and cartridges.
+	A list of disks, tapes and cartridges, and possibly a state snapshot.
 */
 struct Media {
 	std::vector<std::shared_ptr<Storage::Disk::Disk>> disks;
@@ -48,13 +51,16 @@ struct Media {
 };
 
 /*!
-	A list of disks, tapes and cartridges plus information about the machine to which to attach them and its configuration,
-	and instructions on how to launch the software attached, plus a measure of confidence in this target's correctness.
+	Describes a machine and possibly its state; conventionally subclassed to add other machine-specific configuration fields and any
+	necessary instructions on how to launch any software provided, plus a measure of confidence in this target's correctness.
 */
 struct Target {
 	Target(Machine machine) : machine(machine) {}
 	virtual ~Target() {}
 
+	// This field is entirely optional.
+	std::unique_ptr<Reflection::Struct> state;
+
 	Machine machine;
 	Media media;
 	float confidence = 0.0f;

ClockReceiver/ClockReceiver.hpp

@@ -213,7 +213,7 @@ class HalfCycles: public WrappedInt<HalfCycles> {
 
 		/*!
 			Severs from @c this the effect of dividing by @c divisor; @c this will end up with
-			the value of @c this modulo @c divisor and @c divided by @c divisor is returned.
+			the value of @c this modulo @c divisor . @c this divided by @c divisor is returned.
 		*/
 		forceinline Cycles divide_cycles(const Cycles &divisor) {
 			const HalfCycles half_divisor = HalfCycles(divisor);

ClockReceiver/JustInTime.hpp

@@ -103,9 +103,9 @@ template <class T, class LocalTimeScale = HalfCycles, int multiplier = 1, int di
 			}
 
 			if constexpr (has_sequence_points<T>::value) {
-				time_until_event_ -= rhs;
+				time_until_event_ -= rhs * multiplier;
 				if(time_until_event_ <= LocalTimeScale(0)) {
-					time_overrun_ = time_until_event_;
+					time_overrun_ = time_until_event_ / divider;
 					flush();
 					update_sequence_point();
 					return true;
@@ -145,13 +145,21 @@ template <class T, class LocalTimeScale = HalfCycles, int multiplier = 1, int di
 
 		/// @returns the amount of time since the object was last flushed, in the target time scale.
 		[[nodiscard]] forceinline TargetTimeScale time_since_flush() const {
-			// TODO: does this handle conversions properly where TargetTimeScale != LocalTimeScale?
 			if constexpr (divider == 1) {
 				return time_since_update_;
 			}
 			return TargetTimeScale(time_since_update_.as_integral() / divider);
 		}
 
+		/// @returns the amount of time since the object was last flushed, plus the local time scale @c offset,
+		/// converted to the target time scale.
+		[[nodiscard]] forceinline TargetTimeScale time_since_flush(LocalTimeScale offset) const {
+			if constexpr (divider == 1) {
+				return time_since_update_ + offset;
+			}
+			return TargetTimeScale((time_since_update_ + offset).as_integral() / divider);
+		}
+
 		/// Flushes all accumulated time.
 		///
 		/// This does not affect this actor's record of when the next sequence point will occur.
@@ -185,7 +193,7 @@ template <class T, class LocalTimeScale = HalfCycles, int multiplier = 1, int di
 		/// @returns the number of cycles until the next sequence-point-based flush, if the embedded object
 		/// supports sequence points; @c LocalTimeScale() otherwise.
 		[[nodiscard]] LocalTimeScale cycles_until_implicit_flush() const {
-			return time_until_event_;
+			return time_until_event_ / divider;
 		}
 
 		/// Indicates whether a sequence-point-caused flush will occur if the specified period is added.
@@ -196,10 +204,43 @@ template <class T, class LocalTimeScale = HalfCycles, int multiplier = 1, int di
 			return rhs >= time_until_event_;
 		}
 
+		/// Indicates the amount of time, in the local time scale, until the first local slot that falls wholly
+		/// after @c duration, if that delay were to occur in @c offset units of time from now.
+		[[nodiscard]] forceinline LocalTimeScale back_map(TargetTimeScale duration, TargetTimeScale offset) const {
+			// A 1:1 mapping is easy.
+			if constexpr (multiplier == 1 && divider == 1) {
+				return duration;
+			}
+
+			// Work out when this query is placed, and the time to which it relates
+			const auto base = time_since_update_ + offset * divider;
+			const auto target = base + duration * divider;
+
+			// Figure out the number of whole input steps that is required to get
+			// past target, and subtract the number of whole input steps necessary
+			// to get to base.
+			const auto steps_to_base = base.as_integral() / multiplier;
+			const auto steps_to_target = (target.as_integral() + divider - 1) / multiplier;
+
+			return LocalTimeScale(steps_to_target - steps_to_base);
+		}
+
 		/// Updates this template's record of the next sequence point.
 		void update_sequence_point() {
 			if constexpr (has_sequence_points<T>::value) {
-				time_until_event_ = object_.get_next_sequence_point();
+				// Keep a fast path where no conversions will be applied; if conversions are
+				// going to be applied then do a direct max -> max translation rather than
+				// allowing the arithmetic to overflow.
+				if constexpr (divider == 1 && std::is_same_v<LocalTimeScale, TargetTimeScale>) {
+					time_until_event_ = object_.get_next_sequence_point();
+				} else {
+					const auto time = object_.get_next_sequence_point();
+					if(time == TargetTimeScale::max()) {
+						time_until_event_ = LocalTimeScale::max();
+					} else {
+						time_until_event_ = time * divider;
+					}
+				}
 				assert(time_until_event_ > LocalTimeScale(0));
 			}
 		}

Components/1770/1770.cpp

@@ -276,7 +276,10 @@ void WD1770::posit_event(int new_event_type) {
 		goto test_type1_type;
 
 	begin_type1_spin_up:
-		if((command_&0x08) || get_drive().get_motor_on()) goto test_type1_type;
+		if((command_&0x08) || get_drive().get_motor_on()) {
+			set_motor_on(true);
+			goto test_type1_type;
+		}
 		SPIN_UP();
 
 	test_type1_type:
@@ -387,7 +390,10 @@ void WD1770::posit_event(int new_event_type) {
 		distance_into_section_ = 0;
 
 		if((command_&0x08) && has_motor_on_line()) goto test_type2_delay;
-		if(!has_motor_on_line() && !has_head_load_line()) goto test_type2_delay;
+		if(!has_motor_on_line() && !has_head_load_line()) {
+			if(has_motor_on_line()) set_motor_on(true);
+			goto test_type2_delay;
+		}
 
 		if(has_motor_on_line()) goto begin_type2_spin_up;
 		goto begin_type2_load_head;

Components/6850/6850.cpp

@@ -129,8 +129,8 @@ ClockingHint::Preference ACIA::preferred_clocking() const {
 	// because it's unclear when the interrupt might come.
 	if(bits_incoming_ && receive_interrupt_enabled_) return ClockingHint::Preference::RealTime;
 
-	// No clocking required then.
-	return ClockingHint::Preference::None;
+	// Real-time clocking not required then.
+	return ClockingHint::Preference::JustInTime;
 }
 
 bool ACIA::get_interrupt_line() const {

Components/68901/MFP68901.cpp

@@ -208,7 +208,7 @@ void MFP68901::run_for(HalfCycles time) {
 }
 
 HalfCycles MFP68901::get_next_sequence_point() {
-	return HalfCycles(-1);
+	return HalfCycles::max();
 }
 
 // MARK: - Timers

Components/9918/9918.cpp

@@ -750,7 +750,7 @@ HalfCycles TMS9918::get_next_sequence_point() {
 	if(next_line_interrupt_row == -1) {
 		return generate_interrupts_ ?
 			half_cycles_before_internal_cycles(time_until_frame_interrupt) :
-			HalfCycles(-1);
+			HalfCycles::max();
 	}
 
 	// Figure out the number of internal cycles until the next line interrupt, which is the amount

Components/AY38910/AY38910.hpp

@@ -12,6 +12,8 @@
 #include "../../Outputs/Speaker/Implementation/SampleSource.hpp"
 #include "../../Concurrency/AsyncTaskQueue.hpp"
 
+#include "../../Reflection/Struct.hpp"
+
 namespace GI {
 namespace AY38910 {
 
@@ -162,6 +164,8 @@ template <bool is_stereo> class AY38910: public ::Outputs::Speaker::SampleSource
 		uint8_t a_left_ = 255, a_right_ = 255;
 		uint8_t b_left_ = 255, b_right_ = 255;
 		uint8_t c_left_ = 255, c_right_ = 255;
+
+		friend struct State;
 };
 
 /*!
@@ -192,6 +196,29 @@ struct Utility {
 
 };
 
+struct State: public Reflection::StructImpl<State> {
+	uint8_t registers[16]{};
+	uint8_t selected_register = 0;
+
+	// TODO: all audio-production thread state.
+
+	State() {
+		if(needs_declare()) {
+			DeclareField(registers);
+			DeclareField(selected_register);
+		}
+	}
+
+	template <typename AY> void apply(AY &target) {
+		// Establish emulator-thread state
+		for(uint8_t c = 0; c < 16; c++) {
+			target.select_register(c);
+			target.set_register_value(registers[c]);
+		}
+		target.select_register(selected_register);
+	}
+};
+
 }
 }
 

Concurrency/AsyncTaskQueue.cpp

@@ -11,11 +11,11 @@
 using namespace Concurrency;
 
 AsyncTaskQueue::AsyncTaskQueue()
-#ifndef __APPLE__
+#ifndef USE_GCD
 	: should_destruct_(false)
 #endif
 {
-#ifdef __APPLE__
+#ifdef USE_GCD
 	serial_dispatch_queue_ = dispatch_queue_create("com.thomasharte.clocksignal.asyntaskqueue", DISPATCH_QUEUE_SERIAL);
 #else
 	thread_ = std::make_unique<std::thread>([this]() {
@@ -44,7 +44,7 @@ AsyncTaskQueue::AsyncTaskQueue()
 }
 
 AsyncTaskQueue::~AsyncTaskQueue() {
-#ifdef __APPLE__
+#ifdef USE_GCD
 	flush();
 	dispatch_release(serial_dispatch_queue_);
 	serial_dispatch_queue_ = nullptr;
@@ -57,7 +57,7 @@ AsyncTaskQueue::~AsyncTaskQueue() {
 }
 
 void AsyncTaskQueue::enqueue(std::function<void(void)> function) {
-#ifdef __APPLE__
+#ifdef USE_GCD
 	dispatch_async(serial_dispatch_queue_, ^{function();});
 #else
 	std::lock_guard lock(queue_mutex_);
@@ -67,7 +67,7 @@ void AsyncTaskQueue::enqueue(std::function<void(void)> function) {
 }
 
 void AsyncTaskQueue::flush() {
-#ifdef __APPLE__
+#ifdef USE_GCD
 	dispatch_sync(serial_dispatch_queue_, ^{});
 #else
 	auto flush_mutex = std::make_shared<std::mutex>();

Concurrency/AsyncTaskQueue.hpp

@@ -16,8 +16,9 @@
 #include <memory>
 #include <thread>
 
-#ifdef __APPLE__
+#if defined(__APPLE__) && !defined(IGNORE_APPLE)
 #include <dispatch/dispatch.h>
+#define USE_GCD
 #endif
 
 namespace Concurrency {
@@ -47,7 +48,7 @@ class AsyncTaskQueue {
 		void flush();
 
 	private:
-#ifdef __APPLE__
+#ifdef USE_GCD
 		dispatch_queue_t serial_dispatch_queue_;
 #else
 		std::unique_ptr<std::thread> thread_;

Inputs/Joystick.hpp

@@ -9,6 +9,7 @@
 #ifndef Joystick_hpp
 #define Joystick_hpp
 
+#include <cstddef>
 #include <vector>
 
 namespace Inputs {

Inputs/Keyboard.cpp

@@ -8,6 +8,8 @@
 
 #include "Keyboard.hpp"
 
+#include <cstddef>
+
 using namespace Inputs;
 
 Keyboard::Keyboard(const std::set<Key> &essential_modifiers) : essential_modifiers_(essential_modifiers) {

InstructionSets/CachingExecutor.hpp

@@ -9,7 +9,7 @@
 #ifndef CachingExecutor_hpp
 #define CachingExecutor_hpp
 
-#include "Sizes.hpp"
+#include "../Numeric/Sizes.hpp"
 
 #include <array>
 #include <cstdint>

InstructionSets/Disassembler.hpp

@@ -9,7 +9,7 @@
 #ifndef Disassembler_hpp
 #define Disassembler_hpp
 
-#include "Sizes.hpp"
+#include "../Numeric/Sizes.hpp"
 
 #include <list>
 #include <map>

Machines/AmstradCPC/AmstradCPC.cpp

@@ -787,45 +787,43 @@ template <bool has_fdc> class ConcreteMachine:
 			ay_.ay().set_port_handler(&key_state_);
 
 			// construct the list of necessary ROMs
-			const std::string machine_name = "AmstradCPC";
-			std::vector<ROMMachine::ROM> required_roms = {
-				ROMMachine::ROM(machine_name, "the Amstrad Disk Operating System", "amsdos.rom", 16*1024, 0x1fe22ecd)
-			};
-			std::string model_number;
-			uint32_t crcs[2];
+			bool has_amsdos = false;
+			ROM::Name firmware, basic;
+
 			switch(target.model) {
-				default:
-					model_number = "6128";
-					has_128k_ = true;
-					crcs[0] = 0x0219bb74;
-					crcs[1] = 0xca6af63d;
-				break;
 				case Analyser::Static::AmstradCPC::Target::Model::CPC464:
-					model_number = "464";
-					has_128k_ = false;
-					crcs[0] = 0x815752df;
-					crcs[1] = 0x7d9a3bac;
+					firmware = ROM::Name::CPC464Firmware;
+					basic = ROM::Name::CPC464BASIC;
 				break;
 				case Analyser::Static::AmstradCPC::Target::Model::CPC664:
-					model_number = "664";
-					has_128k_ = false;
-					crcs[0] = 0x3f5a6dc4;
-					crcs[1] = 0x32fee492;
+					firmware = ROM::Name::CPC664Firmware;
+					basic = ROM::Name::CPC664BASIC;
+					has_amsdos = true;
+				break;
+				default:
+					firmware = ROM::Name::CPC6128Firmware;
+					basic = ROM::Name::CPC6128BASIC;
+					has_amsdos = true;
 				break;
 			}
-			required_roms.emplace_back(machine_name, "the CPC " + model_number + " firmware", "os" + model_number + ".rom", 16*1024, crcs[0]);
-			required_roms.emplace_back(machine_name, "the CPC " + model_number + " BASIC ROM", "basic" + model_number + ".rom", 16*1024, crcs[1]);
 
-			// fetch and verify the ROMs
-			const auto roms = rom_fetcher(required_roms);
-
-			for(std::size_t index = 0; index < roms.size(); ++index) {
-				auto &data = roms[index];
-				if(!data) throw ROMMachine::Error::MissingROMs;
-				roms_[index] = std::move(*data);
-				roms_[index].resize(16384);
+			ROM::Request request = ROM::Request(firmware) && ROM::Request(basic);
+			if(has_amsdos) {
+				request = request && ROM::Request(ROM::Name::AMSDOS);
 			}
 
+			// Fetch and verify the ROMs.
+			auto roms = rom_fetcher(request);
+			if(!request.validate(roms)) {
+				throw ROMMachine::Error::MissingROMs;
+			}
+
+			if(has_amsdos) {
+				roms_[ROMType::AMSDOS] = roms.find(ROM::Name::AMSDOS)->second;
+			}
+			roms_[ROMType::OS] = roms.find(firmware)->second;
+			roms_[ROMType::BASIC] = roms.find(basic)->second;
+
 			// Establish default memory map
 			upper_rom_is_paged_ = true;
 			upper_rom_ = ROMType::BASIC;

Machines/AmstradCPC/Keyboard.cpp

@@ -151,7 +151,7 @@ const uint16_t *CharacterMapper::sequence_for_character(char character) const {
 #undef SHIFT
 #undef X
 
-	return table_lookup_sequence_for_character(key_sequences, sizeof(key_sequences), character);
+	return table_lookup_sequence_for_character(key_sequences, character);
 }
 
 bool CharacterMapper::needs_pause_after_key(uint16_t key) const {

Machines/Apple/ADB/Keyboard.cpp

@@ -16,6 +16,7 @@ void Keyboard::perform_command(const Command &command) {
 	switch(command.type) {
 		case Command::Type::Reset:
 			modifiers_ = 0xffff;
+			[[fallthrough]];
 		case Command::Type::Flush: {
 			std::lock_guard lock_guard(keys_mutex_);
 			pending_events_.clear();

Machines/Apple/AppleII/AppleII.cpp

@@ -48,7 +48,6 @@ template <Analyser::Static::AppleII::Target::Model model> class ConcreteMachine:
 	public MachineTypes::MappedKeyboardMachine,
 	public MachineTypes::JoystickMachine,
 	public CPU::MOS6502::BusHandler,
-	public Inputs::Keyboard,
 	public Configurable::Device,
 	public Activity::Source,
 	public Apple::II::Card::Delegate {
@@ -66,7 +65,11 @@ template <Analyser::Static::AppleII::Target::Model model> class ConcreteMachine:
 				uint8_t *ram_, *aux_ram_;
 		};
 
-		CPU::MOS6502::Processor<(model == Analyser::Static::AppleII::Target::Model::EnhancedIIe) ? CPU::MOS6502::Personality::PSynertek65C02 : CPU::MOS6502::Personality::P6502, ConcreteMachine, false> m6502_;
+		using Processor = CPU::MOS6502::Processor<
+			(model == Analyser::Static::AppleII::Target::Model::EnhancedIIe) ? CPU::MOS6502::Personality::PSynertek65C02 : CPU::MOS6502::Personality::P6502,
+			ConcreteMachine,
+			false>;
+		Processor m6502_;
 		VideoBusHandler video_bus_handler_;
 		Apple::II::Video::Video<VideoBusHandler, is_iie()> video_;
 		int cycles_into_current_line_ = 0;
@@ -91,16 +94,6 @@ template <Analyser::Static::AppleII::Target::Model model> class ConcreteMachine:
 
 		uint8_t ram_[65536], aux_ram_[65536];
 		std::vector<uint8_t> rom_;
-		uint8_t keyboard_input_ = 0x00;
-		bool key_is_down_ = false;
-
-		uint8_t get_keyboard_input() {
-			if(string_serialiser_) {
-				return string_serialiser_->head() | 0x80;
-			} else {
-				return keyboard_input_;
-			}
-		}
 
 		Concurrency::DeferringAsyncTaskQueue audio_queue_;
 		Audio::Toggle audio_toggle_;
@@ -258,16 +251,99 @@ template <Analyser::Static::AppleII::Target::Model model> class ConcreteMachine:
 				state.region_20_40.write ? &aux_ram_[0x2000] : &ram_[0x2000]);
 		}
 
-		// MARK - typing
-		std::unique_ptr<Utility::StringSerialiser> string_serialiser_;
+		// MARK: - Keyboard and typing.
 
-		// MARK - Joysticks.
+		struct Keyboard: public Inputs::Keyboard {
+			Keyboard(Processor *m6502) : m6502_(m6502) {}
+
+			void reset_all_keys() final {
+				open_apple_is_pressed = closed_apple_is_pressed = key_is_down = false;
+			}
+
+			bool set_key_pressed(Key key, char value, bool is_pressed) final {
+				// If no ASCII value is supplied, look for a few special cases.
+				switch(key) {
+					case Key::Left:			value = 0x08;	break;
+					case Key::Right:		value = 0x15;	break;
+					case Key::Down:			value = 0x0a;	break;
+					case Key::Up:			value = 0x0b;	break;
+					case Key::Backspace:	value = 0x7f;	break;
+					case Key::Enter:		value = 0x0d;	break;
+					case Key::Tab:			value = '\t';	break;
+					case Key::Escape:		value = 0x1b;	break;
+
+					case Key::LeftOption:
+					case Key::RightMeta:
+						open_apple_is_pressed = is_pressed;
+					return true;
+
+					case Key::RightOption:
+					case Key::LeftMeta:
+						closed_apple_is_pressed = is_pressed;
+					return true;
+
+					case Key::F1:	case Key::F2:	case Key::F3:	case Key::F4:
+					case Key::F5:	case Key::F6:	case Key::F7:	case Key::F8:
+					case Key::F9:	case Key::F10:	case Key::F11:	case Key::F12:
+					case Key::PrintScreen:
+					case Key::ScrollLock:
+					case Key::Pause:
+					case Key::Insert:
+					case Key::Home:
+					case Key::PageUp:
+					case Key::PageDown:
+					case Key::End:
+						// Accept a bunch non-symbolic other keys, as
+						// reset, in the hope that the user can find
+						// at least one usable key.
+						m6502_->set_reset_line(is_pressed);
+					return true;
+
+					default:
+						if(!value) {
+							return false;
+						}
+
+						// Prior to the IIe, the keyboard could produce uppercase only.
+						if(!is_iie()) value = char(toupper(value));
+					break;
+				}
+
+				if(is_pressed) {
+					keyboard_input = uint8_t(value | 0x80);
+					key_is_down = true;
+				} else {
+					if((keyboard_input & 0x7f) == value) {
+						key_is_down = false;
+					}
+				}
+
+				return true;
+			}
+
+			uint8_t get_keyboard_input() {
+				if(string_serialiser) {
+					return string_serialiser->head() | 0x80;
+				} else {
+					return keyboard_input;
+				}
+			}
+
+			// The IIe has three keys that are wired directly to the same input as the joystick buttons.
+			bool open_apple_is_pressed = false;
+			bool closed_apple_is_pressed = false;
+			uint8_t keyboard_input = 0x00;
+			bool key_is_down = false;
+			std::unique_ptr<Utility::StringSerialiser> string_serialiser;
+
+			private:
+			Processor *const m6502_;
+		};
+		Keyboard keyboard_;
+
+		// MARK: - Joysticks.
 		JoystickPair joysticks_;
 
-		// The IIe has three keys that are wired directly to the same input as the joystick buttons.
-		bool open_apple_is_pressed_ = false;
-		bool closed_apple_is_pressed_ = false;
-
 	public:
 		ConcreteMachine(const Analyser::Static::AppleII::Target &target, const ROMMachine::ROMFetcher &rom_fetcher):
 			m6502_(*this),
@@ -276,7 +352,8 @@ template <Analyser::Static::AppleII::Target::Model model> class ConcreteMachine:
 			audio_toggle_(audio_queue_),
 			speaker_(audio_toggle_),
 			language_card_(*this),
-			auxiliary_switches_(*this) {
+			auxiliary_switches_(*this),
+			keyboard_(&m6502_) {
 			// The system's master clock rate.
 			constexpr float master_clock = 14318180.0;
 
@@ -300,49 +377,55 @@ template <Analyser::Static::AppleII::Target::Model model> class ConcreteMachine:
 
 			// Pick the required ROMs.
 			using Target = Analyser::Static::AppleII::Target;
-			const std::string machine_name = "AppleII";
-			std::vector<ROMMachine::ROM> rom_descriptions;
-			size_t rom_size = 12*1024;
+			ROM::Name character, system;
+
 			switch(target.model) {
 				default:
-					rom_descriptions.push_back(video_.rom_description(Video::VideoBase::CharacterROM::II));
-					rom_descriptions.emplace_back(machine_name, "the original Apple II ROM", "apple2o.rom", 12*1024, 0xba210588);
+					character = ROM::Name::AppleIICharacter;
+					system = ROM::Name::AppleIIOriginal;
 				break;
 				case Target::Model::IIplus:
-					rom_descriptions.push_back(video_.rom_description(Video::VideoBase::CharacterROM::II));
-					rom_descriptions.emplace_back(machine_name, "the Apple II+ ROM", "apple2.rom", 12*1024, 0xf66f9c26);
+					character = ROM::Name::AppleIICharacter;
+					system = ROM::Name::AppleIIPlus;
 				break;
 				case Target::Model::IIe:
-					rom_size += 3840;
-					rom_descriptions.push_back(video_.rom_description(Video::VideoBase::CharacterROM::IIe));
-					rom_descriptions.emplace_back(machine_name, "the Apple IIe ROM", "apple2eu.rom", 32*1024, 0xe12be18d);
+					character = ROM::Name::AppleIIeCharacter;
+					system = ROM::Name::AppleIIe;
 				break;
 				case Target::Model::EnhancedIIe:
-					rom_size += 3840;
-					rom_descriptions.push_back(video_.rom_description(Video::VideoBase::CharacterROM::EnhancedIIe));
-					rom_descriptions.emplace_back(machine_name, "the Enhanced Apple IIe ROM", "apple2e.rom", 32*1024, 0x65989942);
+					character = ROM::Name::AppleIIEnhancedECharacter;
+					system = ROM::Name::AppleIIEnhancedE;
 				break;
 			}
-			const auto roms = rom_fetcher(rom_descriptions);
 
-			// Try to install a Disk II card now, before checking the ROM list,
-			// to make sure that Disk II dependencies have been communicated.
-			if(target.disk_controller != Target::DiskController::None) {
+			ROM::Request request = ROM::Request(character) && ROM::Request(system);
+
+			// Add the necessary Disk II requests if appropriate.
+			const bool has_disk_controller = target.disk_controller != Target::DiskController::None;
+			const bool is_sixteen_sector = target.disk_controller == Target::DiskController::SixteenSector;
+			if(has_disk_controller) {
 				// Apple recommended slot 6 for the (first) Disk II.
-				install_card(6, new Apple::II::DiskIICard(rom_fetcher, target.disk_controller == Target::DiskController::SixteenSector));
+				request = request && DiskIICard::rom_request(is_sixteen_sector);
 			}
 
-			// Now, check and move the ROMs.
-			if(!roms[0] || !roms[1]) {
+			// Request, validate and install ROMs.
+			auto roms = rom_fetcher(request);
+			if(!request.validate(roms)) {
 				throw ROMMachine::Error::MissingROMs;
 			}
 
-			rom_ = std::move(*roms[1]);
-			if(rom_.size() > rom_size) {
-				rom_.erase(rom_.begin(), rom_.end() - off_t(rom_size));
+			if(has_disk_controller) {
+				install_card(6, new Apple::II::DiskIICard(roms, is_sixteen_sector));
 			}
 
-			video_.set_character_rom(*roms[0]);
+			rom_ = std::move(roms.find(system)->second);
+			// The IIe and Enhanced IIe ROMs often distributed are oversized; trim if necessary.
+			if(system == ROM::Name::AppleIIe || system == ROM::Name::AppleIIEnhancedE) {
+				if(rom_.size() > 16128) {
+					rom_.erase(rom_.begin(), rom_.end() - off_t(16128));
+				}
+			}
+			video_.set_character_rom(roms.find(character)->second);
 
 			// Set up the default memory blocks. On a II or II+ these values will never change.
 			// On a IIe they'll be affected by selection of auxiliary RAM.
@@ -435,18 +518,18 @@ template <Analyser::Static::AppleII::Target::Model model> class ConcreteMachine:
 								default: break;
 
 								case 0xc000:
-									*value = get_keyboard_input();
+									*value = keyboard_.get_keyboard_input();
 								break;
 								case 0xc001: case 0xc002: case 0xc003: case 0xc004: case 0xc005: case 0xc006: case 0xc007:
 								case 0xc008: case 0xc009: case 0xc00a: case 0xc00b: case 0xc00c: case 0xc00d: case 0xc00e: case 0xc00f:
-									*value = (*value & 0x80) | (get_keyboard_input() & 0x7f);
+									*value = (*value & 0x80) | (keyboard_.get_keyboard_input() & 0x7f);
 								break;
 
 								case 0xc061:	// Switch input 0.
 									*value &= 0x7f;
 									if(
 										joysticks_.button(0) ||
-										(is_iie() && open_apple_is_pressed_)
+										(is_iie() && keyboard_.open_apple_is_pressed)
 									)
 										*value |= 0x80;
 								break;
@@ -454,7 +537,7 @@ template <Analyser::Static::AppleII::Target::Model model> class ConcreteMachine:
 									*value &= 0x7f;
 									if(
 										joysticks_.button(1) ||
-										(is_iie() && closed_apple_is_pressed_)
+										(is_iie() && keyboard_.closed_apple_is_pressed)
 									)
 										*value |= 0x80;
 								break;
@@ -476,7 +559,7 @@ template <Analyser::Static::AppleII::Target::Model model> class ConcreteMachine:
 								} break;
 
 								// The IIe-only state reads follow...
-#define IIeSwitchRead(s)	*value = get_keyboard_input(); if(is_iie()) *value = (*value & 0x7f) | (s ? 0x80 : 0x00);
+#define IIeSwitchRead(s)	*value = keyboard_.get_keyboard_input(); if(is_iie()) *value = (*value & 0x7f) | (s ? 0x80 : 0x00);
 								case 0xc011:	IIeSwitchRead(language_card_.state().bank2);								break;
 								case 0xc012:	IIeSwitchRead(language_card_.state().read);									break;
 								case 0xc013:	IIeSwitchRead(auxiliary_switches_.switches().read_auxiliary_memory);		break;
@@ -559,15 +642,15 @@ template <Analyser::Static::AppleII::Target::Model model> class ConcreteMachine:
 					break;
 
 					case 0xc010:
-						keyboard_input_ &= 0x7f;
-						if(string_serialiser_) {
-							if(!string_serialiser_->advance())
-								string_serialiser_.reset();
+						keyboard_.keyboard_input &= 0x7f;
+						if(keyboard_.string_serialiser) {
+							if(!keyboard_.string_serialiser->advance())
+								keyboard_.string_serialiser.reset();
 						}
 
 						// On the IIe, reading C010 returns additional key info.
 						if(is_iie() && isReadOperation(operation)) {
-							*value = (key_is_down_ ? 0x80 : 0x00) | (keyboard_input_ & 0x7f);
+							*value = (keyboard_.key_is_down ? 0x80 : 0x00) | (keyboard_.keyboard_input & 0x7f);
 						}
 					break;
 
@@ -683,81 +766,16 @@ template <Analyser::Static::AppleII::Target::Model model> class ConcreteMachine:
 			m6502_.run_for(cycles);
 		}
 
-		void reset_all_keys() final {
-			open_apple_is_pressed_ = closed_apple_is_pressed_ = key_is_down_ = false;
-		}
-
 		bool prefers_logical_input() final {
 			return true;
 		}
 
-		bool set_key_pressed(Key key, char value, bool is_pressed) final {
-			// If no ASCII value is supplied, look for a few special cases.
-			switch(key) {
-				case Key::Left:			value = 0x08;	break;
-				case Key::Right:		value = 0x15;	break;
-				case Key::Down:			value = 0x0a;	break;
-				case Key::Up:			value = 0x0b;	break;
-				case Key::Backspace:	value = 0x7f;	break;
-				case Key::Enter:		value = 0x0d;	break;
-				case Key::Tab:			value = '\t';	break;
-				case Key::Escape:		value = 0x1b;	break;
-
-				case Key::LeftOption:
-				case Key::RightMeta:
-					open_apple_is_pressed_ = is_pressed;
-				return true;
-
-				case Key::RightOption:
-				case Key::LeftMeta:
-					closed_apple_is_pressed_ = is_pressed;
-				return true;
-
-				case Key::F1:	case Key::F2:	case Key::F3:	case Key::F4:
-				case Key::F5:	case Key::F6:	case Key::F7:	case Key::F8:
-				case Key::F9:	case Key::F10:	case Key::F11:	case Key::F12:
-				case Key::PrintScreen:
-				case Key::ScrollLock:
-				case Key::Pause:
-				case Key::Insert:
-				case Key::Home:
-				case Key::PageUp:
-				case Key::PageDown:
-				case Key::End:
-					// Accept a bunch non-symbolic other keys, as
-					// reset, in the hope that the user can find
-					// at least one usable key.
-					m6502_.set_reset_line(is_pressed);
-				return true;
-
-				default:
-					if(!value) {
-						return false;
-					}
-
-					// Prior to the IIe, the keyboard could produce uppercase only.
-					if(!is_iie()) value = char(toupper(value));
-				break;
-			}
-
-			if(is_pressed) {
-				keyboard_input_ = uint8_t(value | 0x80);
-				key_is_down_ = true;
-			} else {
-				if((keyboard_input_ & 0x7f) == value) {
-					key_is_down_ = false;
-				}
-			}
-
-			return true;
-		}
-
 		Inputs::Keyboard &get_keyboard() final {
-			return *this;
+			return keyboard_;
 		}
 
 		void type_string(const std::string &string) final {
-			string_serialiser_ = std::make_unique<Utility::StringSerialiser>(string, true);
+			keyboard_.string_serialiser = std::make_unique<Utility::StringSerialiser>(string, true);
 		}
 
 		bool can_type(char c) const final {
@@ -769,12 +787,14 @@ template <Analyser::Static::AppleII::Target::Model model> class ConcreteMachine:
 		std::unique_ptr<Reflection::Struct> get_options() final {
 			auto options = std::make_unique<Options>(Configurable::OptionsType::UserFriendly);
 			options->output = get_video_signal_configurable();
+			options->use_square_pixels = video_.get_use_square_pixels();
 			return options;
 		}
 
 		void set_options(const std::unique_ptr<Reflection::Struct> &str) {
 			const auto options = dynamic_cast<Options *>(str.get());
 			set_video_signal_configurable(options->output);
+			video_.set_use_square_pixels(options->use_square_pixels);
 		}
 
 		// MARK: MediaTarget

Machines/Apple/AppleII/AppleII.hpp

@@ -30,8 +30,11 @@ class Machine {
 		class Options: public Reflection::StructImpl<Options>, public Configurable::DisplayOption<Options> {
 			friend Configurable::DisplayOption<Options>;
 			public:
-				Options(Configurable::OptionsType) : Configurable::DisplayOption<Options>(Configurable::Display::CompositeColour)  {
+				bool use_square_pixels = false;
+
+				Options(Configurable::OptionsType) : Configurable::DisplayOption<Options>(Configurable::Display::CompositeColour) {
 					if(needs_declare()) {
+						DeclareField(use_square_pixels);
 						declare_display_option();
 						limit_enum(&output, Configurable::Display::CompositeMonochrome, Configurable::Display::CompositeColour, -1);
 					}

Machines/Apple/AppleII/DiskIICard.cpp

@@ -10,27 +10,34 @@
 
 using namespace Apple::II;
 
-DiskIICard::DiskIICard(const ROMMachine::ROMFetcher &rom_fetcher, bool is_16_sector) : diskii_(2045454) {
-	std::vector<std::unique_ptr<std::vector<uint8_t>>> roms;
+ROM::Request DiskIICard::rom_request(bool is_16_sector) {
 	if(is_16_sector) {
-		roms = rom_fetcher({
-			{"DiskII", "the Disk II 16-sector boot ROM", "boot-16.rom", 256, 0xce7144f6},
-			{"DiskII", "the Disk II 16-sector state machine ROM", "state-machine-16.rom", 256, { 0x9796a238, 0xb72a2c70 } }
-		});
+		return ROM::Request(ROM::Name::DiskIIBoot16Sector) && ROM::Request(ROM::Name::DiskIIStateMachine16Sector);
 	} else {
-		roms = rom_fetcher({
-			{"DiskII", "the Disk II 13-sector boot ROM", "boot-13.rom", 256, 0xd34eb2ff},
-			{"DiskII", "the Disk II 16-sector state machine ROM", "state-machine-16.rom", 256, { 0x9796a238, 0xb72a2c70 } }
-//			{"DiskII", "the Disk II 13-sector state machine ROM", "state-machine-13.rom", 256, 0x62e22620 }
-			/* TODO: once the DiskII knows how to decode common images of the 13-sector state machine, use that instead of the 16-sector. */
-		});
+		/* TODO: once the DiskII knows how to decode common images of the 13-sector state machine, use that instead of the 16-sector. */
+		return ROM::Request(ROM::Name::DiskIIBoot13Sector) && ROM::Request(ROM::Name::DiskIIStateMachine16Sector);
 	}
-	if(!roms[0] || !roms[1]) {
+}
+
+
+DiskIICard::DiskIICard(ROM::Map &map, bool is_16_sector) : diskii_(2045454) {
+	std::vector<std::unique_ptr<std::vector<uint8_t>>> roms;
+	ROM::Map::iterator state_machine, boot;
+	if(is_16_sector) {
+		state_machine = map.find(ROM::Name::DiskIIStateMachine16Sector);
+		boot = map.find(ROM::Name::DiskIIBoot16Sector);
+	} else {
+		// TODO: see above re: 13-sector state machine.
+		state_machine = map.find(ROM::Name::DiskIIStateMachine16Sector);
+		boot = map.find(ROM::Name::DiskIIBoot13Sector);
+	}
+
+	if(state_machine == map.end() || boot == map.end()) {
 		throw ROMMachine::Error::MissingROMs;
 	}
 
-	boot_ = std::move(*roms[0]);
-	diskii_.set_state_machine(*roms[1]);
+	boot_ = std::move(boot->second);
+	diskii_.set_state_machine(state_machine->second);
 	set_select_constraints(None);
 	diskii_.set_clocking_hint_observer(this);
 }

Machines/Apple/AppleII/DiskIICard.hpp

@@ -25,7 +25,8 @@ namespace II {
 
 class DiskIICard: public Card, public ClockingHint::Observer {
 	public:
-		DiskIICard(const ROMMachine::ROMFetcher &rom_fetcher, bool is_16_sector);
+		static ROM::Request rom_request(bool is_16_sector);
+		DiskIICard(ROM::Map &, bool is_16_sector);
 
 		void perform_bus_operation(Select select, bool is_read, uint16_t address, uint8_t *value) final;
 		void run_for(Cycles cycles, int stretches) final;

Machines/Apple/AppleII/Video.cpp

@@ -15,9 +15,8 @@ VideoBase::VideoBase(bool is_iie, std::function<void(Cycles)> &&target) :
 	crt_(910, 1, Outputs::Display::Type::NTSC60, Outputs::Display::InputDataType::Luminance1),
 	is_iie_(is_iie) {
 
-	// Show only the centre 75% of the TV frame.
 	crt_.set_display_type(Outputs::Display::DisplayType::CompositeColour);
-	crt_.set_visible_area(Outputs::Display::Rect(0.118f, 0.122f, 0.77f, 0.77f));
+	set_use_square_pixels(use_square_pixels_);
 
 	// TODO: there seems to be some sort of bug whereby switching modes can cause
 	// a signal discontinuity that knocks phase out of whack. So it isn't safe to
@@ -26,6 +25,41 @@ VideoBase::VideoBase(bool is_iie, std::function<void(Cycles)> &&target) :
 //	crt_.set_immediate_default_phase(0.5f);
 }
 
+void VideoBase::set_use_square_pixels(bool use_square_pixels) {
+	use_square_pixels_ = use_square_pixels;
+
+	// HYPER-UGLY HACK. See correlated hack in the Macintosh.
+#if defined(__APPLE__) && !defined(IGNORE_APPLE)
+	crt_.set_visible_area(Outputs::Display::Rect(0.128f, 0.122f, 0.75f, 0.77f));
+#else
+	if(use_square_pixels) {
+		crt_.set_visible_area(Outputs::Display::Rect(0.128f, 0.09f, 0.75f, 0.77f));
+	} else {
+		crt_.set_visible_area(Outputs::Display::Rect(0.128f, 0.12f, 0.75f, 0.77f));
+	}
+#endif
+
+	if(use_square_pixels) {
+		// From what I can make out, many contemporary Apple II monitors were
+		// calibrated slightly to stretch the Apple II's display slightly wider
+		// than it should be per the NTSC standards, for approximately square
+		// pixels. This reproduces that.
+
+		// 243 lines and 52µs are visible.
+		// i.e. to be square, 1 pixel should be: (1/243 * 52) * (3/4) = 156/972 = 39/243 µs
+		// On an Apple II each pixel is actually 1/7µs.
+		// Therefore the adjusted aspect ratio should be (4/3) * (39/243)/(1/7) = (4/3) * 273/243 = 1092/729 = 343/243 ~= 1.412
+		crt_.set_aspect_ratio(343.0f / 243.0f);
+	} else {
+		// Standard NTSC aspect ratio.
+		crt_.set_aspect_ratio(4.0f / 3.0f);
+	}
+}
+bool VideoBase::get_use_square_pixels() {
+	return use_square_pixels_;
+}
+
+
 void VideoBase::set_scan_target(Outputs::Display::ScanTarget *scan_target) {
 	crt_.set_scan_target(scan_target);
 }

Machines/Apple/AppleII/Video.hpp

@@ -51,8 +51,14 @@ class VideoBase: public VideoSwitches<Cycles> {
 		/// Gets the type of output.
 		Outputs::Display::DisplayType get_display_type() const;
 
+		/// Sets whether the current CRT should be recalibrated away from normative NTSC
+		/// to produce square pixels in 40-column text mode.
+		void set_use_square_pixels(bool);
+		bool get_use_square_pixels();
+
 	protected:
 		Outputs::CRT::CRT crt_;
+		bool use_square_pixels_ = false;
 
 		// State affecting output video stream generation.
 		uint8_t *pixel_pointer_ = nullptr;
@@ -393,7 +399,7 @@ template <class BusHandler, bool is_iie> class Video: public VideoBase {
 							// The OpenGL scan target introduces a phase error of 1/8th of a wave. The Metal one does not.
 							// Supply the real phase value if this is an Apple build.
 							// TODO: eliminate UGLY HACK.
-#ifdef __APPLE__
+#if defined(__APPLE__) && !defined(IGNORE_APPLE)
 							constexpr int phase = 224;
 #else
 							constexpr int phase = 0;

Machines/Apple/AppleII/VideoSwitches.hpp

@@ -228,36 +228,6 @@ template <typename TimeUnit> class VideoSwitches {
 			return external_.annunciator_3;
 		}
 
-		enum class CharacterROM {
-			/// The ROM that shipped with both the Apple II and the II+.
-			II,
-			/// The ROM that shipped with the original IIe.
-			IIe,
-			/// The ROM that shipped with the Enhanced IIe.
-			EnhancedIIe,
-			/// The ROM that shipped with the IIgs.
-			IIgs
-		};
-
-		/// @returns A file-level description of @c rom.
-		static ROMMachine::ROM rom_description(CharacterROM rom) {
-			const std::string machine_name = "AppleII";
-			switch(rom) {
-				case CharacterROM::II:
-					return ROMMachine::ROM(machine_name, "the basic Apple II character ROM", "apple2-character.rom", 2*1024, 0x64f415c6);
-
-				case CharacterROM::IIe:
-					return ROMMachine::ROM(machine_name, "the Apple IIe character ROM", "apple2eu-character.rom", 4*1024, 0x816a86f1);
-
-				default:	// To appease GCC.
-				case CharacterROM::EnhancedIIe:
-					return ROMMachine::ROM(machine_name, "the Enhanced Apple IIe character ROM", "apple2e-character.rom", 4*1024, 0x2651014d);
-
-				case CharacterROM::IIgs:
-					return ROMMachine::ROM(machine_name, "the Apple IIgs character ROM", "apple2gs.chr", 4*1024, 0x91e53cd8);
-			}
-		}
-
 		/// Set the character ROM for this video output.
 		void set_character_rom(const std::vector<uint8_t> &rom) {
 			character_rom_ = rom;

Machines/Apple/AppleIIgs/AppleIIgs.cpp

@@ -189,31 +189,23 @@ class ConcreteMachine:
 			speaker_.set_input_rate(float(CLOCK_RATE) / float(audio_divider));
 
 			using Target = Analyser::Static::AppleIIgs::Target;
-			std::vector<ROMMachine::ROM> rom_descriptions;
-			const std::string machine_name = "AppleIIgs";
+			ROM::Name system;
 			switch(target.model) {
-				case Target::Model::ROM00:
-					/* TODO */
-				case Target::Model::ROM01:
-					rom_descriptions.emplace_back(machine_name, "the Apple IIgs ROM01", "apple2gs.rom", 128*1024, 0x42f124b0);
-				break;
-
-				case Target::Model::ROM03:
-					rom_descriptions.emplace_back(machine_name, "the Apple IIgs ROM03", "apple2gs.rom2", 256*1024, 0xde7ddf29);
-				break;
+				case Target::Model::ROM00:	system = ROM::Name::AppleIIgsROM00;	break;
+				case Target::Model::ROM01:	system = ROM::Name::AppleIIgsROM01;	break;
+				default:					system = ROM::Name::AppleIIgsROM03;	break;
 			}
-			rom_descriptions.push_back(video_->rom_description(Video::Video::CharacterROM::EnhancedIIe));
+			constexpr ROM::Name characters = ROM::Name::AppleIIEnhancedECharacter;
+			constexpr ROM::Name microcontroller = ROM::Name::AppleIIgsMicrocontrollerROM03;
 
-			// TODO: pick a different ADB ROM for earlier machine revisions?
-			rom_descriptions.emplace_back(machine_name, "the Apple IIgs ADB microcontroller ROM", "341s0632-2", 4*1024, 0xe1c11fb0);
-
-			const auto roms = rom_fetcher(rom_descriptions);
-			if(!roms[0] || !roms[1] || !roms[2]) {
+			ROM::Request request = ROM::Request(system) && ROM::Request(characters) && ROM::Request(microcontroller);
+			auto roms = rom_fetcher(request);
+			if(!request.validate(roms)) {
 				throw ROMMachine::Error::MissingROMs;
 			}
-			rom_ = *roms[0];
-			video_->set_character_rom(*roms[1]);
-			adb_glu_->set_microcontroller_rom(*roms[2]);
+			rom_ = roms.find(system)->second;
+			video_->set_character_rom(roms.find(characters)->second);
+			adb_glu_->set_microcontroller_rom(roms.find(microcontroller)->second);
 
 			// Run only the currently-interesting self test.
 //			rom_[0x36402] = 2;

Machines/Apple/Macintosh/Keyboard.hpp

@@ -271,7 +271,7 @@ class Keyboard {
 		/// so this may not be valid prior to Mode::PerformingCommand.
 		int command_ = 0;
 		/// Populated during PerformingCommand as the response to the most-recently-received command, this
-		/// is then shifted out to teh host computer. So it is guaranteed valid at the beginning of Mode::SendingResponse,
+		/// is then shifted out to the host computer. So it is guaranteed valid at the beginning of Mode::SendingResponse,
 		/// but not afterwards.
 		int response_ = 0;
 

Machines/Apple/Macintosh/Macintosh.cpp

@@ -96,25 +96,24 @@ template <Analyser::Static::Macintosh::Target::Model model> class ConcreteMachin
 			using Model = Analyser::Static::Macintosh::Target::Model;
 			const std::string machine_name = "Macintosh";
 			uint32_t ram_size, rom_size;
-			std::vector<ROMMachine::ROM> rom_descriptions;
+			ROM::Name rom_name;
 			switch(model) {
 				default:
 				case Model::Mac128k:
 					ram_size = 128*1024;
 					rom_size = 64*1024;
-					rom_descriptions.emplace_back(machine_name, "the Macintosh 128k ROM", "mac128k.rom", 64*1024, 0x6d0c8a28);
+					rom_name = ROM::Name::Macintosh128k;
 				break;
 				case Model::Mac512k:
 					ram_size = 512*1024;
 					rom_size = 64*1024;
-					rom_descriptions.emplace_back(machine_name, "the Macintosh 512k ROM", "mac512k.rom", 64*1024, 0xcf759e0d);
+					rom_name = ROM::Name::Macintosh512k;
 				break;
 				case Model::Mac512ke:
 				case Model::MacPlus: {
 					ram_size = ((model == Model::MacPlus) ? 4096 : 512)*1024;
 					rom_size = 128*1024;
-					const std::initializer_list<uint32_t> crc32s = { 0x4fa5b399, 0x7cacd18f, 0xb2102e8e };
-					rom_descriptions.emplace_back(machine_name, "the Macintosh Plus ROM", "macplus.rom", 128*1024, crc32s);
+					rom_name = ROM::Name::MacintoshPlus;
 				} break;
 			}
 			ram_mask_ = ram_size - 1;
@@ -123,12 +122,12 @@ template <Analyser::Static::Macintosh::Target::Model model> class ConcreteMachin
 			video_.set_ram(reinterpret_cast<uint16_t *>(ram_.data()), ram_mask_ >> 1);
 
 			// Grab a copy of the ROM and convert it into big-endian data.
-			const auto roms = rom_fetcher(rom_descriptions);
-			if(!roms[0]) {
+			ROM::Request request(rom_name);
+			auto roms = rom_fetcher(request);
+			if(!request.validate(roms)) {
 				throw ROMMachine::Error::MissingROMs;
 			}
-			roms[0]->resize(rom_size);
-			Memory::PackBigEndian16(*roms[0], rom_);
+			Memory::PackBigEndian16(roms.find(rom_name)->second, rom_);
 
 			// Randomise memory contents.
 			Memory::Fuzz(ram_);

Machines/Apple/Macintosh/Video.cpp

@@ -35,7 +35,7 @@ Video::Video(DeferredAudio &audio, DriveSpeedAccumulator &drive_speed_accumulato
 	// The [newer] Metal scan target has no such issue. So assume that Apple => Metal,
 	// and set a visible area to work around the OpenGL issue if required.
 	// TODO: eliminate UGLY HACK.
-#ifdef __APPLE__
+#if defined(__APPLE__) && !defined(IGNORE_APPLE)
 	crt_.set_visible_area(Outputs::Display::Rect(0.08f, 10.0f / 368.0f, 0.82f, 344.0f / 368.0f));
 #else
 	crt_.set_visible_area(Outputs::Display::Rect(0.08f, -0.025f, 0.82f, 0.82f));

Machines/Atari/ST/AtariST.cpp

@@ -74,15 +74,13 @@ class ConcreteMachine:
 			video_->set_ram(reinterpret_cast<uint16_t *>(ram_.data()), ram_.size());
 			Memory::Fuzz(ram_);
 
-			std::vector<ROMMachine::ROM> rom_descriptions = {
-				{"AtariST", "the UK TOS 1.00 ROM", "tos100.img", 192*1024, 0x1a586c64}
-//				{"AtariST", "the UK TOS 1.04 ROM", "tos104.img", 192*1024, 0xa50d1d43}
-			};
-			const auto roms = rom_fetcher(rom_descriptions);
-			if(!roms[0]) {
+			constexpr ROM::Name rom_name = ROM::Name::AtariSTTOS100;
+			ROM::Request request(rom_name);
+			auto roms = rom_fetcher(request);
+			if(!request.validate(roms)) {
 				throw ROMMachine::Error::MissingROMs;
 			}
-			Memory::PackBigEndian16(*roms[0], rom_);
+			Memory::PackBigEndian16(roms.find(rom_name)->second, rom_);
 
 			// Set up basic memory map.
 			memory_map_[0] = BusDevice::MostlyRAM;

Machines/Atari/ST/DMAController.cpp

@@ -252,7 +252,7 @@ void DMAController::set_component_prefers_clocking(ClockingHint::Source *, Clock
 }
 
 ClockingHint::Preference DMAController::preferred_clocking() const {
-	return (fdc_.preferred_clocking() == ClockingHint::Preference::None) ? ClockingHint::Preference::None : ClockingHint::Preference::RealTime;
+	return (fdc_.preferred_clocking() == ClockingHint::Preference::None) ? ClockingHint::Preference::JustInTime : ClockingHint::Preference::RealTime;
 }
 
 void DMAController::set_activity_observer(Activity::Observer *observer) {

Machines/ColecoVision/ColecoVision.cpp

@@ -127,15 +127,13 @@ class ConcreteMachine:
 			joysticks_.emplace_back(new Joystick);
 			joysticks_.emplace_back(new Joystick);
 
-			const auto roms = rom_fetcher(
-				{ {"ColecoVision", "the ColecoVision BIOS", "coleco.rom", 8*1024, 0x3aa93ef3} });
-
-			if(!roms[0]) {
+			constexpr ROM::Name rom_name = ROM::Name::ColecoVisionBIOS;
+			const ROM::Request request(rom_name);
+			auto roms = rom_fetcher(request);
+			if(!request.validate(roms)) {
 				throw ROMMachine::Error::MissingROMs;
 			}
-
-			bios_ = *roms[0];
-			bios_.resize(8192);
+			bios_ = roms.find(rom_name)->second;
 
 			if(!target.media.cartridges.empty()) {
 				const auto &segment = target.media.cartridges.front()->get_segments().front();

Machines/Commodore/1540/C1540.hpp

@@ -41,7 +41,8 @@ namespace C1540 {
 */
 class Machine final: public MachineBase {
 	public:
-		Machine(Personality personality, const ROMMachine::ROMFetcher &rom_fetcher);
+		static ROM::Request rom_request(Personality personality);
+		Machine(Personality personality, const ROM::Map &roms);
 
 		/*!
 			Sets the serial bus to which this drive should attach itself.

Machines/Commodore/1540/Implementation/C1540.cpp

@@ -16,7 +16,15 @@
 
 using namespace Commodore::C1540;
 
-MachineBase::MachineBase(Personality personality, const ROMMachine::ROMFetcher &rom_fetcher) :
+ROM::Request Machine::rom_request(Personality personality) {
+	switch(personality) {
+		default:
+		case Personality::C1540:	return ROM::Request(ROM::Name::Commodore1540);
+		case Personality::C1541:	return ROM::Request(ROM::Name::Commodore1541);
+	}
+}
+
+MachineBase::MachineBase(Personality personality, const ROM::Map &roms) :
 		Storage::Disk::Controller(1000000),
 		m6502_(*this),
 		serial_port_VIA_port_handler_(new SerialPortVIA(serial_port_VIA_)),
@@ -39,28 +47,22 @@ MachineBase::MachineBase(Personality personality, const ROMMachine::ROMFetcher &
 	emplace_drive(1000000, 300, 2);
 	set_drive(1);
 
-	std::string device_name;
-	uint32_t crc = 0;
+	ROM::Name rom_name;
 	switch(personality) {
-		case Personality::C1540:
-			device_name = "1540";
-			crc = 0x718d42b1;
-		break;
-		case Personality::C1541:
-			device_name = "1541";
-			crc = 0xfb760019;
-		break;
+		default:
+		case Personality::C1540:	rom_name = ROM::Name::Commodore1540;	break;
+		case Personality::C1541:	rom_name = ROM::Name::Commodore1541;	break;
 	}
 
-	auto roms = rom_fetcher({ {"Commodore1540", "the " + device_name + " ROM", device_name + ".bin", 16*1024, crc} });
-	if(!roms[0]) {
+	auto rom = roms.find(rom_name);
+	if(rom == roms.end()) {
 		throw ROMMachine::Error::MissingROMs;
 	}
-	std::memcpy(rom_, roms[0]->data(), std::min(sizeof(rom_), roms[0]->size()));
+	std::memcpy(rom_, roms.find(rom_name)->second.data(), std::min(sizeof(rom_), roms.find(rom_name)->second.size()));
 }
 
-Machine::Machine(Personality personality, const ROMMachine::ROMFetcher &rom_fetcher) :
-	MachineBase(personality, rom_fetcher) {}
+Machine::Machine(Personality personality, const ROM::Map &roms) :
+	MachineBase(personality, roms) {}
 
 void Machine::set_serial_bus(std::shared_ptr<::Commodore::Serial::Bus> serial_bus) {
 	Commodore::Serial::AttachPortAndBus(serial_port_, serial_bus);

Machines/Commodore/1540/Implementation/C1540Base.hpp

@@ -127,7 +127,7 @@ class MachineBase:
 	public Storage::Disk::Controller {
 
 	public:
-		MachineBase(Personality personality, const ROMMachine::ROMFetcher &rom_fetcher);
+		MachineBase(Personality personality, const ROM::Map &roms);
 
 		// to satisfy CPU::MOS6502::Processor
 		Cycles perform_bus_operation(CPU::MOS6502::BusOperation operation, uint16_t address, uint8_t *value);

Machines/Commodore/Vic-20/Keyboard.cpp

@@ -151,5 +151,5 @@ const uint16_t *CharacterMapper::sequence_for_character(char character) const {
 #undef SHIFT
 #undef X
 
-	return table_lookup_sequence_for_character(key_sequences, sizeof(key_sequences), character);
+	return table_lookup_sequence_for_character(key_sequences, character);
 }

Machines/Commodore/Vic-20/Vic20.cpp

@@ -316,53 +316,48 @@ class ConcreteMachine:
 			// Install a joystick.
 			joysticks_.emplace_back(new Joystick(*user_port_via_port_handler_, *keyboard_via_port_handler_));
 
-			const std::string machine_name = "Vic20";
-			std::vector<ROMMachine::ROM> rom_names = {
-				{machine_name, "the VIC-20 BASIC ROM", "basic.bin", 8*1024, 0xdb4c43c1}
-			};
+			ROM::Request request(ROM::Name::Vic20BASIC);
+			ROM::Name kernel, character;
 			switch(target.region) {
 				default:
-					rom_names.emplace_back(machine_name, "the English-language VIC-20 character ROM", "characters-english.bin", 4*1024, 0x83e032a6);
-					rom_names.emplace_back(machine_name, "the English-language PAL VIC-20 kernel ROM", "kernel-pal.bin", 8*1024, 0x4be07cb4);
+					character = ROM::Name::Vic20EnglishCharacters;
+					kernel = ROM::Name::Vic20EnglishPALKernel;
 				break;
 				case Analyser::Static::Commodore::Target::Region::American:
-					rom_names.emplace_back(machine_name, "the English-language VIC-20 character ROM", "characters-english.bin", 4*1024, 0x83e032a6);
-					rom_names.emplace_back(machine_name, "the English-language NTSC VIC-20 kernel ROM", "kernel-ntsc.bin", 8*1024, 0xe5e7c174);
+					character = ROM::Name::Vic20EnglishCharacters;
+					kernel = ROM::Name::Vic20EnglishNTSCKernel;
 				break;
 				case Analyser::Static::Commodore::Target::Region::Danish:
-					rom_names.emplace_back(machine_name, "the Danish VIC-20 character ROM", "characters-danish.bin", 4*1024, 0x7fc11454);
-					rom_names.emplace_back(machine_name, "the Danish VIC-20 kernel ROM", "kernel-danish.bin", 8*1024, 0x02adaf16);
+					character = ROM::Name::Vic20DanishCharacters;
+					kernel = ROM::Name::Vic20DanishKernel;
 				break;
 				case Analyser::Static::Commodore::Target::Region::Japanese:
-					rom_names.emplace_back(machine_name, "the Japanese VIC-20 character ROM", "characters-japanese.bin", 4*1024, 0xfcfd8a4b);
-					rom_names.emplace_back(machine_name, "the Japanese VIC-20 kernel ROM", "kernel-japanese.bin", 8*1024, 0x336900d7);
+					character = ROM::Name::Vic20JapaneseCharacters;
+					kernel = ROM::Name::Vic20JapaneseKernel;
 				break;
 				case Analyser::Static::Commodore::Target::Region::Swedish:
-					rom_names.emplace_back(machine_name, "the Swedish VIC-20 character ROM", "characters-swedish.bin", 4*1024, 0xd808551d);
-					rom_names.emplace_back(machine_name, "the Swedish VIC-20 kernel ROM", "kernel-swedish.bin", 8*1024, 0xb2a60662);
+					character = ROM::Name::Vic20SwedishCharacters;
+					kernel = ROM::Name::Vic20SwedishKernel;
 				break;
 			}
 
-			const auto roms = rom_fetcher(rom_names);
+			if(target.has_c1540) {
+				request = request && Commodore::C1540::Machine::rom_request(Commodore::C1540::Personality::C1540);
+			}
+			request = request && ROM::Request(character) && ROM::Request(kernel);
 
-			for(const auto &rom: roms) {
-				if(!rom) {
-					throw ROMMachine::Error::MissingROMs;
-				}
+			auto roms = rom_fetcher(request);
+			if(!request.validate(roms)) {
+				throw ROMMachine::Error::MissingROMs;
 			}
 
-			basic_rom_ = std::move(*roms[0]);
-			character_rom_ = std::move(*roms[1]);
-			kernel_rom_ = std::move(*roms[2]);
-
-			// Characters ROMs should be 4kb.
-			character_rom_.resize(4096);
-			// Kernel ROMs and the BASIC ROM should be 8kb.
-			kernel_rom_.resize(8192);
+			basic_rom_ = std::move(roms.find(ROM::Name::Vic20BASIC)->second);
+			character_rom_ = std::move(roms.find(character)->second);
+			kernel_rom_ = std::move(roms.find(kernel)->second);
 
 			if(target.has_c1540) {
 				// construct the 1540
-				c1540_ = std::make_unique<::Commodore::C1540::Machine>(Commodore::C1540::Personality::C1540, rom_fetcher);
+				c1540_ = std::make_unique<::Commodore::C1540::Machine>(Commodore::C1540::Personality::C1540, roms);
 
 				// attach it to the serial bus
 				c1540_->set_serial_bus(serial_bus_);

Machines/Electron/Electron.cpp

@@ -69,37 +69,25 @@ template <bool has_scsi_bus> class ConcreteMachine:
 			speaker_.set_input_rate(2000000 / SoundGenerator::clock_rate_divider);
 			speaker_.set_high_frequency_cutoff(6000);
 
-			const std::string machine_name = "Electron";
-			std::vector<ROMMachine::ROM> required_roms = {
-				{machine_name, "the Acorn BASIC II ROM", "basic.rom", 16*1024, 0x79434781},
-				{machine_name, "the Electron MOS ROM", "os.rom", 16*1024, 0xbf63fb1f}
-			};
-			const size_t pres_adfs_rom_position = required_roms.size();
+			::ROM::Request request = ::ROM::Request(::ROM::Name::AcornBASICII) && ::ROM::Request(::ROM::Name::AcornElectronMOS100);
 			if(target.has_pres_adfs) {
-				required_roms.emplace_back(machine_name, "the E00 ADFS ROM, first slot", "ADFS-E00_1.rom", 16*1024, 0x51523993);
-				required_roms.emplace_back(machine_name, "the E00 ADFS ROM, second slot", "ADFS-E00_2.rom", 16*1024, 0x8d17de0e);
+				request = request && ::ROM::Request(::ROM::Name::PRESADFSSlot1) && ::ROM::Request(::ROM::Name::PRESADFSSlot2);
 			}
-			const size_t acorn_adfs_rom_position = required_roms.size();
 			if(target.has_acorn_adfs) {
-				required_roms.emplace_back(machine_name, "the Acorn ADFS ROM", "adfs.rom", 16*1024, 0x3289bdc6);
+				request = request && ::ROM::Request(::ROM::Name::AcornADFS);
 			}
-			const size_t dfs_rom_position = required_roms.size();
 			if(target.has_dfs) {
-				required_roms.emplace_back(machine_name, "the 1770 DFS ROM", "DFS-1770-2.20.rom", 16*1024, 0xf3dc9bc5);
+				request = request && ::ROM::Request(::ROM::Name::Acorn1770DFS);
 			}
-			const size_t ap6_rom_position = required_roms.size();
 			if(target.has_ap6_rom) {
-				required_roms.emplace_back(machine_name, "the 8kb Advanced Plus 6 ROM", "AP6v133.rom", 8*1024, 0xe0013cfc);
+				request = request && ::ROM::Request(::ROM::Name::PRESAdvancedPlus6);
 			}
-			const auto roms = rom_fetcher(required_roms);
-
-			for(const auto &rom: roms) {
-				if(!rom) {
-					throw ROMMachine::Error::MissingROMs;
-				}
+			auto roms = rom_fetcher(request);
+			if(!request.validate(roms)) {
+				throw ROMMachine::Error::MissingROMs;
 			}
-			set_rom(ROM::BASIC, *roms[0], false);
-			set_rom(ROM::OS, *roms[1], false);
+			set_rom(ROM::BASIC, roms.find(::ROM::Name::AcornBASICII)->second, false);
+			set_rom(ROM::OS, roms.find(::ROM::Name::AcornElectronMOS100)->second, false);
 
 			/*
 				ROM slot mapping applied:
@@ -115,19 +103,18 @@ template <bool has_scsi_bus> class ConcreteMachine:
 				plus3_ = std::make_unique<Plus3>();
 
 				if(target.has_dfs) {
-					set_rom(ROM::Slot0, *roms[dfs_rom_position], true);
+					set_rom(ROM::Slot0, roms.find(::ROM::Name::Acorn1770DFS)->second, true);
 				}
 				if(target.has_pres_adfs) {
-					set_rom(ROM::Slot4, *roms[pres_adfs_rom_position], true);
-					set_rom(ROM::Slot5, *roms[pres_adfs_rom_position+1], true);
+					set_rom(ROM::Slot4, roms.find(::ROM::Name::PRESADFSSlot1)->second, true);
+					set_rom(ROM::Slot5, roms.find(::ROM::Name::PRESADFSSlot2)->second, true);
 				}
 				if(target.has_acorn_adfs) {
-					set_rom(ROM::Slot6, *roms[acorn_adfs_rom_position], true);
+					set_rom(ROM::Slot6, roms.find(::ROM::Name::AcornADFS)->second, true);
 				}
 			}
-
 			if(target.has_ap6_rom) {
-				set_rom(ROM::Slot15, *roms[ap6_rom_position], true);
+				set_rom(ROM::Slot15, roms.find(::ROM::Name::PRESAdvancedPlus6)->second, true);
 			}
 
 			if(target.has_sideways_ram) {

Machines/Electron/Keyboard.cpp

@@ -145,7 +145,7 @@ const uint16_t *CharacterMapper::sequence_for_character(char character) const {
 #undef SHIFT
 #undef X
 
-	return table_lookup_sequence_for_character(key_sequences, sizeof(key_sequences), character);
+	return table_lookup_sequence_for_character(key_sequences, character);
 }
 
 bool CharacterMapper::needs_pause_after_key(uint16_t key) const {

Machines/Enterprise/Dave.cpp

@@ -0,0 +1,326 @@
+//
+//  Dave.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 22/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#include "Dave.hpp"
+
+using namespace Enterprise::Dave;
+
+// MARK: - Audio generator
+
+Audio::Audio(Concurrency::DeferringAsyncTaskQueue &audio_queue) :
+	audio_queue_(audio_queue) {}
+
+void Audio::write(uint16_t address, uint8_t value) {
+	address &= 0xf;
+	audio_queue_.defer([address, value, this] {
+		switch(address) {
+			case 0:	case 2:	case 4:
+				channels_[address >> 1].reload = (channels_[address >> 1].reload & 0xff00) | value;
+			break;
+			case 1:	case 3:	case 5:
+				channels_[address >> 1].reload = uint16_t((channels_[address >> 1].reload & 0x00ff) | ((value & 0xf) << 8));
+				channels_[address >> 1].distortion = Channel::Distortion((value >> 4)&3);
+				channels_[address >> 1].high_pass = value & 0x40;
+				channels_[address >> 1].ring_modulate = value & 0x80;
+			break;
+			case 6:
+				noise_.frequency = Noise::Frequency(value&3);
+				noise_.polynomial = Noise::Polynomial((value >> 2)&3);
+				noise_.swap_polynomial = value & 0x10;
+				noise_.low_pass = value & 0x20;
+				noise_.high_pass = value & 0x40;
+				noise_.ring_modulate = value & 0x80;
+			break;
+
+			case 7:
+				channels_[0].sync = value & 0x01;
+				channels_[1].sync = value & 0x02;
+				channels_[2].sync = value & 0x04;
+				use_direct_output_[0] = value & 0x08;
+				use_direct_output_[1] = value & 0x10;
+				// Interrupt bits are handled separately.
+			break;
+
+			case 8: case 9: case 10:
+				channels_[address - 8].amplitude[0] = value & 0x3f;
+			break;
+			case 12: case 13: case 14:
+				channels_[address - 12].amplitude[1] = value & 0x3f;
+			break;
+			case 11:	noise_.amplitude[0] = value & 0x3f;		break;
+			case 15:	noise_.amplitude[1] = value & 0x3f;		break;
+		}
+	});
+}
+
+void Audio::set_sample_volume_range(int16_t range) {
+	audio_queue_.defer([range, this] {
+		volume_ = range / (63*4);
+	});
+}
+
+void Audio::update_channel(int c) {
+	if(channels_[c].sync) {
+		channels_[c].count = channels_[c].reload;
+		channels_[c].output <<= 1;
+		return;
+	}
+
+	auto output = channels_[c].output & 1;
+	channels_[c].output <<= 1;
+	if(!channels_[c].count) {
+		channels_[c].count = channels_[c].reload;
+
+		if(channels_[c].distortion == Channel::Distortion::None)
+			output ^= 1;
+		else
+			output = poly_state_[int(channels_[c].distortion)];
+
+		if(channels_[c].high_pass && (channels_[(c+1)%3].output&3) == 2) {
+			output = 0;
+		}
+		if(channels_[c].ring_modulate) {
+			output = ~(output ^ channels_[(c+2)%3].output) & 1;
+		}
+	} else {
+		--channels_[c].count;
+	}
+
+	channels_[c].output |= output;
+}
+
+void Audio::get_samples(std::size_t number_of_samples, int16_t *target) {
+	for(size_t c = 0; c < number_of_samples; c++) {
+		poly_state_[int(Channel::Distortion::FourBit)] = poly4_.next();
+		poly_state_[int(Channel::Distortion::FiveBit)] = poly5_.next();
+		poly_state_[int(Channel::Distortion::SevenBit)] = poly7_.next();
+		if(noise_.swap_polynomial) {
+			poly_state_[int(Channel::Distortion::SevenBit)] = poly_state_[int(Channel::Distortion::None)];
+		}
+
+		// Update tone channels.
+		update_channel(0);
+		update_channel(1);
+		update_channel(2);
+
+		// Update noise channel.
+
+		// Step 1: decide whether there is a tick to apply.
+		bool noise_tick = false;
+		if(noise_.frequency == Noise::Frequency::DivideByFour) {
+			if(!noise_.count) {
+				noise_tick = true;
+				noise_.count = 3;
+			} else {
+				--noise_.count;
+			}
+		} else {
+			noise_tick = (channels_[int(noise_.frequency) - 1].output&3) == 2;
+		}
+
+		// Step 2: tick if necessary.
+		int noise_output = noise_.output & 1;
+		noise_.output <<= 1;
+		if(noise_tick) {
+			switch(noise_.polynomial) {
+				case Noise::Polynomial::SeventeenBit:
+					poly_state_[int(Channel::Distortion::None)] = uint8_t(poly17_.next());
+				break;
+				case Noise::Polynomial::FifteenBit:
+					poly_state_[int(Channel::Distortion::None)] = uint8_t(poly15_.next());
+				break;
+				case Noise::Polynomial::ElevenBit:
+					poly_state_[int(Channel::Distortion::None)] = uint8_t(poly11_.next());
+				break;
+				case Noise::Polynomial::NineBit:
+					poly_state_[int(Channel::Distortion::None)] = uint8_t(poly9_.next());
+				break;
+			}
+
+			noise_output = poly_state_[int(Channel::Distortion::None)];
+		}
+		noise_.output |= noise_output;
+
+		// Low pass: sample channel 2 on downward transitions of the prima facie output.
+		if(noise_.low_pass && (noise_.output & 3) == 2) {
+			noise_.output = (noise_.output & ~1) | (channels_[2].output & 1);
+		}
+
+		// Apply noise high-pass.
+		if(noise_.high_pass && (channels_[0].output & 3) == 2) {
+			noise_.output &= ~1;
+		}
+
+		// Update noise ring modulation, if any.
+		if(noise_.ring_modulate) {
+			noise_.final_output = !((noise_.output ^ channels_[1].output) & 1);
+		} else {
+			noise_.final_output = noise_.output & 1;
+		}
+
+		// I'm unclear on the details of the time division multiplexing so,
+		// for now, just sum the outputs.
+		target[(c << 1) + 0] =
+			volume_ *
+				(use_direct_output_[0] ?
+					channels_[0].amplitude[0]
+					: (
+						channels_[0].amplitude[0] * (channels_[0].output & 1) +
+						channels_[1].amplitude[0] * (channels_[1].output & 1) +
+						channels_[2].amplitude[0] * (channels_[2].output & 1) +
+						noise_.amplitude[0] * noise_.final_output
+				));
+
+		target[(c << 1) + 1] =
+			volume_ *
+				(use_direct_output_[1] ?
+					channels_[0].amplitude[1]
+					: (
+						channels_[0].amplitude[1] * (channels_[0].output & 1) +
+						channels_[1].amplitude[1] * (channels_[1].output & 1) +
+						channels_[2].amplitude[1] * (channels_[2].output & 1) +
+						noise_.amplitude[1] * noise_.final_output
+				));
+	}
+}
+
+// MARK: - Interrupt source
+
+uint8_t TimedInterruptSource::get_new_interrupts() {
+	const uint8_t result = interrupts_;
+	interrupts_ = 0;
+	return result;
+}
+
+void TimedInterruptSource::write(uint16_t address, uint8_t value) {
+	address &= 15;
+	switch(address) {
+		default: break;
+
+		case 0: case 2:
+			channels_[address >> 1].reload = (channels_[address >> 1].reload & 0xff00) | value;
+		break;
+		case 1:	case 3:
+			channels_[address >> 1].reload = uint16_t((channels_[address >> 1].reload & 0x00ff) | ((value & 0xf) << 8));
+		break;
+
+		case 7: {
+			channels_[0].sync = value & 0x01;
+			channels_[1].sync = value & 0x02;
+
+			const InterruptRate rate = InterruptRate((value >> 5) & 3);
+			if(rate != rate_) {
+				rate_ = rate;
+
+				if(rate_ >= InterruptRate::ToneGenerator0) {
+					programmable_level_ = channels_[int(rate_) - int(InterruptRate::ToneGenerator0)].level;
+				} else {
+					programmable_offset_ = programmble_reload(rate_);
+				}
+			}
+		} break;
+	}
+}
+
+void TimedInterruptSource::update_channel(int c, bool is_linked, int decrement) {
+	if(channels_[c].sync) {
+		channels_[c].value = channels_[c].reload;
+	} else {
+		if(decrement <= channels_[c].value) {
+			channels_[c].value -= decrement;
+		} else {
+			// The decrement is greater than the current value, therefore
+			// there'll be at least one flip.
+			//
+			// After decreasing the decrement by the current value + 1,
+			// it'll be clear how many decrements are left after reload.
+			//
+			// Dividing that by the number of decrements necessary for a
+			// flip will provide the total number of flips.
+			const int decrements_after_flip = decrement - (channels_[c].value + 1);
+			const int num_flips = 1 + decrements_after_flip / (channels_[c].reload + 1);
+
+			// If this is a linked channel, set the interrupt mask if a transition
+			// from high to low is amongst the included flips.
+			if(is_linked && num_flips + channels_[c].level >= 2) {
+				interrupts_ |= uint8_t(Interrupt::VariableFrequency);
+			}
+			channels_[c].level ^= (num_flips & 1);
+
+			// Apply the modulo number of decrements to the reload value to
+			// figure out where things stand now.
+			channels_[c].value = channels_[c].reload - decrements_after_flip % (channels_[c].reload + 1);
+		}
+	}
+}
+
+void TimedInterruptSource::run_for(Cycles cycles) {
+	// Update the 1Hz interrupt.
+	one_hz_offset_ -= cycles;
+	if(one_hz_offset_ <= Cycles(0)) {
+		interrupts_ |= uint8_t(Interrupt::OneHz);
+		one_hz_offset_ += clock_rate;
+	}
+
+	// Update the two tone channels.
+	update_channel(0, rate_ == InterruptRate::ToneGenerator0, cycles.as<int>());
+	update_channel(1, rate_ == InterruptRate::ToneGenerator1, cycles.as<int>());
+
+	// Update the programmable-frequency interrupt.
+	if(rate_ < InterruptRate::ToneGenerator0) {
+		programmable_offset_ -= cycles.as<int>();
+		if(programmable_offset_ <= 0) {
+			if(programmable_level_) {
+				interrupts_ |= uint8_t(Interrupt::VariableFrequency);
+			}
+			programmable_level_ ^= true;
+			programmable_offset_ = programmble_reload(rate_);
+		}
+	}
+}
+
+Cycles TimedInterruptSource::get_next_sequence_point() const {
+	int result = one_hz_offset_.as<int>();
+
+	switch(rate_) {
+		case InterruptRate::OnekHz:
+		case InterruptRate::FiftyHz:
+			result = std::min(result, programmable_offset_ + (!programmable_level_) * programmble_reload(rate_));
+		break;
+		case InterruptRate::ToneGenerator0:
+		case InterruptRate::ToneGenerator1: {
+			const auto &channel = channels_[int(rate_) - int(InterruptRate::ToneGenerator0)];
+			const int cycles_until_interrupt = channel.value + 1 + (!channel.level) * (channel.reload + 1);
+			result = std::min(result, cycles_until_interrupt);
+		} break;
+	}
+
+	return Cycles(result);
+}
+
+uint8_t TimedInterruptSource::get_divider_state() {
+	bool programmable_flag = false;
+	switch(rate_) {
+		case InterruptRate::OnekHz:
+		case InterruptRate::FiftyHz:
+			programmable_flag = programmable_level_;
+		break;
+		case InterruptRate::ToneGenerator0:
+			programmable_flag = channels_[0].level;
+		break;
+		case InterruptRate::ToneGenerator1:
+			programmable_flag = channels_[1].level;
+		break;
+	}
+
+	// one_hz_offset_ counts downwards, so when it crosses the halfway mark
+	// it enters the high part of its wave.
+	return
+		(one_hz_offset_ < half_clock_rate ? 0x4 : 0x0) |
+		(programmable_flag ? 0x1 : 0x0);
+}

Machines/Enterprise/Dave.hpp

@@ -0,0 +1,188 @@
+//
+//  Dave.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 22/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#ifndef Dave_hpp
+#define Dave_hpp
+
+#include <cstdint>
+
+#include "../../ClockReceiver/ClockReceiver.hpp"
+#include "../../Concurrency/AsyncTaskQueue.hpp"
+#include "../../Numeric/LFSR.hpp"
+#include "../../Outputs/Speaker/Implementation/SampleSource.hpp"
+
+namespace Enterprise {
+namespace Dave {
+
+enum class Interrupt: uint8_t {
+	VariableFrequency = 0x02,
+	OneHz = 0x08,
+	Nick = 0x20,
+};
+
+/*!
+	Models the audio-production subset of Dave's behaviour.
+*/
+class Audio: public Outputs::Speaker::SampleSource {
+	public:
+		Audio(Concurrency::DeferringAsyncTaskQueue &audio_queue);
+
+		/// Modifies an register in the audio range; only the low 4 bits are
+		/// used for register decoding so it's assumed that the caller has
+		/// already identified this write as being to an audio register.
+		void write(uint16_t address, uint8_t value);
+
+		// MARK: - SampleSource.
+		void set_sample_volume_range(int16_t range);
+		static constexpr bool get_is_stereo() { return true; }	// Dave produces stereo sound.
+		void get_samples(std::size_t number_of_samples, int16_t *target);
+
+	private:
+		Concurrency::DeferringAsyncTaskQueue &audio_queue_;
+
+		// Tone channels.
+		struct Channel {
+			// User-set values.
+			uint16_t reload = 0;
+			bool high_pass = false;
+			bool ring_modulate = false;
+			enum class Distortion {
+				None = 0,
+				FourBit = 1,
+				FiveBit = 2,
+				SevenBit = 3,
+			} distortion = Distortion::None;
+			uint8_t amplitude[2]{};
+			bool sync = false;
+
+			// Current state.
+			uint16_t count = 0;
+			int output = 0;
+		} channels_[3];
+		void update_channel(int);
+
+		// Noise channel.
+		struct Noise {
+			// User-set values.
+			uint8_t amplitude[2]{};
+			enum class Frequency {
+				DivideByFour,
+				ToneChannel0,
+				ToneChannel1,
+				ToneChannel2,
+			} frequency = Frequency::DivideByFour;
+			enum class Polynomial {
+				SeventeenBit,
+				FifteenBit,
+				ElevenBit,
+				NineBit
+			} polynomial = Polynomial::SeventeenBit;
+			bool swap_polynomial = false;
+			bool low_pass = false;
+			bool high_pass = false;
+			bool ring_modulate = false;
+
+			// Current state.
+			int count = 0;
+			int output = 0;
+			bool final_output = false;
+		} noise_;
+		void update_noise();
+
+		bool use_direct_output_[2]{};
+
+		// Global volume, per SampleSource obligations.
+		int16_t volume_ = 0;
+
+		// Polynomials that are always running.
+		Numeric::LFSRv<0xc> poly4_;
+		Numeric::LFSRv<0x14> poly5_;
+		Numeric::LFSRv<0x60> poly7_;
+
+		// The selectable, noise-related polynomial.
+		Numeric::LFSRv<0x110> poly9_;
+		Numeric::LFSRv<0x500> poly11_;
+		Numeric::LFSRv<0x6000> poly15_;
+		Numeric::LFSRv<0x12000> poly17_;
+
+		// Current state of the active polynomials.
+		uint8_t poly_state_[4];
+};
+
+/*!
+	Provides Dave's timed interrupts — those that are provided at 1 kHz,
+	50 Hz or according to the rate of tone generators 0 or 1, plus the fixed
+	1 Hz interrupt.
+*/
+class TimedInterruptSource {
+	public:
+		/// Modifies an register in the audio range; only the low 4 bits are
+		/// used for register decoding so it's assumed that the caller has
+		/// already identified this write as being to an audio register.
+		void write(uint16_t address, uint8_t value);
+
+		/// Returns a bitmask of interrupts that have become active since
+		/// the last time this method was called; flags are as defined in
+		/// @c Enterprise::Dave::Interrupt
+		uint8_t get_new_interrupts();
+
+		/// Returns the current high or low states of the inputs that trigger
+		/// the interrupts modelled here, as a bit mask compatible with that
+		/// exposed by Dave as the register at 0xb4.
+		uint8_t get_divider_state();
+
+		/// Advances the interrupt source.
+		void run_for(Cycles);
+
+		/// @returns The amount of time from now until the earliest that
+		/// @c get_new_interrupts() _might_ have new interrupts to report.
+		Cycles get_next_sequence_point() const;
+
+	private:
+		static constexpr Cycles clock_rate{250000};
+		static constexpr Cycles half_clock_rate{125000};
+
+		// Interrupts that have fired since get_new_interrupts()
+		// was last called.
+		uint8_t interrupts_ = 0;
+
+		// A counter for the 1Hz interrupt.
+		Cycles one_hz_offset_ = clock_rate;
+
+		// A counter specific to the 1kHz and 50Hz timers, if in use.
+		enum class InterruptRate {
+			OnekHz,
+			FiftyHz,
+			ToneGenerator0,
+			ToneGenerator1,
+		} rate_ = InterruptRate::OnekHz;
+		int programmable_offset_ = programmble_reload(InterruptRate::OnekHz);
+		bool programmable_level_ = false;
+
+		// A local duplicate of the counting state of the first two audio
+		// channels, maintained in case either of those is used as an
+		// interrupt source.
+		struct Channel {
+			int value = 100, reload = 100;
+			bool sync = false;
+			bool level = false;
+		} channels_[2];
+		void update_channel(int c, bool is_linked, int decrement);
+		static constexpr int programmble_reload(InterruptRate rate) {
+			switch(rate) {
+				default: return 0;
+				case InterruptRate::OnekHz:		return 125;
+				case InterruptRate::FiftyHz:	return 2500;
+			}
+		}
+};
+
+}
+}
+
+#endif /* Dave_hpp */

Machines/Enterprise/EXDos.cpp

@@ -0,0 +1,78 @@
+//
+//  EXDos.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 20/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#include "EXDos.hpp"
+
+// TODO: disk_did_change_ should be on the drive. Some drives report it.
+
+using namespace Enterprise;
+
+EXDos::EXDos() : WD1770(P1770) {
+	emplace_drives(4, 8000000, 300, 2);
+	set_control_register(0x00);
+}
+
+void EXDos::set_disk(std::shared_ptr<Storage::Disk::Disk> disk, size_t drive) {
+	get_drive(drive).set_disk(disk);
+	disk_did_change_ = true;
+}
+
+// Documentation for the control register:
+//
+//	Write:
+//		b7	in use				(???)
+//		b6	disk change reset
+//		b5	0 = double density, 1 = single density
+//		b4	side 1 select
+//		b3, b3, b1, b0	select drive 3, 2, 1, 0
+//
+//	Read:
+//		b7 data request from WD1770
+//		b6 disk change
+//		b5, b4, b3, b2: not used
+//		b1 interrupt request from WD1770
+//		b0 drive ready
+
+void EXDos::set_control_register(uint8_t control) {
+	if(control & 0x40) disk_did_change_ = false;
+	set_is_double_density(!(control & 0x20));
+
+	// Set side.
+	const int head = (control >> 4) & 1;
+	for(size_t c = 0; c < 4; c++) {
+		get_drive(c).set_head(head);
+	}
+
+	// Select drive, ensuring handover of the motor-on state.
+	const bool motor_state = get_drive().get_motor_on();
+	for_all_drives([] (Storage::Disk::Drive &drive, size_t) {
+		drive.set_motor_on(false);
+	});
+	set_drive(control & 0xf);
+	get_drive().set_motor_on(motor_state);
+}
+
+uint8_t EXDos::get_control_register() {
+	const uint8_t status =
+		(get_data_request_line() ? 0x80 : 0x00) |
+		(disk_did_change_ ? 0x40 : 0x00) |
+		(get_interrupt_request_line() ? 0x02 : 0x00) |
+		(get_drive().get_is_ready() ? 0x01 : 0x00);
+
+	return status;
+}
+
+void EXDos::set_motor_on(bool on) {
+	get_drive().set_motor_on(on);
+}
+
+void EXDos::set_activity_observer(Activity::Observer *observer) {
+	for_all_drives([observer] (Storage::Disk::Drive &drive, size_t index) {
+		drive.set_activity_observer(observer, "Drive " + std::to_string(index+1), true);
+	});
+}

Machines/Enterprise/EXDos.hpp

@@ -0,0 +1,36 @@
+//
+//  EXDos.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 20/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#ifndef EXDos_hpp
+#define EXDos_hpp
+
+#include "../../Components/1770/1770.hpp"
+#include "../../Activity/Observer.hpp"
+
+namespace Enterprise {
+
+class EXDos final : public WD::WD1770 {
+	public:
+		EXDos();
+
+		void set_disk(std::shared_ptr<Storage::Disk::Disk> disk, size_t drive);
+
+		void set_control_register(uint8_t control);
+		uint8_t get_control_register();
+
+		void set_activity_observer(Activity::Observer *observer);
+
+	private:
+		bool disk_did_change_ = false;
+
+		void set_motor_on(bool on) override;
+};
+
+}
+
+#endif /* EXDos_hpp */

Machines/Enterprise/Enterprise.cpp

@@ -0,0 +1,740 @@
+//
+//  Enterprise.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 10/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#include "Enterprise.hpp"
+
+#include "Dave.hpp"
+#include "EXDos.hpp"
+#include "Keyboard.hpp"
+#include "Nick.hpp"
+
+#include "../MachineTypes.hpp"
+#include "../Utility/Typer.hpp"
+
+#include "../../Analyser/Static/Enterprise/Target.hpp"
+#include "../../ClockReceiver/JustInTime.hpp"
+#include "../../Outputs/Speaker/Implementation/LowpassSpeaker.hpp"
+#include "../../Processors/Z80/Z80.hpp"
+
+#define LOG_PREFIX "[Enterprise] "
+#include "../../Outputs/Log.hpp"
+
+namespace Enterprise {
+
+/*
+	Notes to self on timing:
+
+	Nick divides each line into 57 windows; each window lasts 16 cycles and dedicates the
+	first 10 of those to VRAM accesses, leaving the final six for a Z80 video RAM access
+	if one has been requested.
+
+	The Z80 has a separate, asynchronous 4Mhz clock. That's that.
+
+	The documentation is also very forward in emphasising that Nick generates phaselocked
+	(i.e. in-phase) PAL video.
+
+	So: 57*16 = 912 cycles/line.
+
+	A standard PAL line lasts 64µs and during that time outputs 283.7516 colour cycles.
+
+	I shall _guess_ that the Enterprise stretches each line to 284 colour cycles rather than
+	reducing it to 283.
+
+	Therefore 912 cycles occurs in 284/283.7516 * 64 µs.
+
+	So one line = 181760000 / 2837516 µs = 45440000 / 709379 µs
+	=> one cycle = 45440000 / 709379*912 = 45440000 / 646953648 = 2840000 / 40434603 µs
+	=> clock rate of 40434603 / 2840000 Mhz
+
+	And, therefore, the ratio to a 4Mhz Z80 clock is:
+
+		40434603 / (2840000 * 4)
+		= 40434603 / 11360000
+		i.e. roughly 3.55 Nick cycles per Z80 cycle.
+
+	If that's true then the 6-cycle window is around 1.69 Z80 cycles long. Given that the Z80
+	clock in an Enterprise can be stopped in half-cycle increments only, the Z80 can only be
+	guaranteed to have around a 1.19 cycle minimum for its actual access. I'm therefore further
+	postulating that the clock stoppage takes place so as to align the final cycle of a relevant
+	access over the available window.
+
+*/
+
+template <bool has_disk_controller> class ConcreteMachine:
+	public Activity::Source,
+	public Configurable::Device,
+	public CPU::Z80::BusHandler,
+	public Machine,
+	public MachineTypes::AudioProducer,
+	public MachineTypes::MappedKeyboardMachine,
+	public MachineTypes::MediaTarget,
+	public MachineTypes::ScanProducer,
+	public MachineTypes::TimedMachine,
+	public Utility::TypeRecipient<CharacterMapper> {
+	private:
+		constexpr uint8_t min_ram_slot(const Analyser::Static::Enterprise::Target &target) {
+			size_t ram_size = 128*1024;
+			switch(target.model) {
+				case Analyser::Static::Enterprise::Target::Model::Enterprise64:		ram_size = 64*1024;		break;
+				case Analyser::Static::Enterprise::Target::Model::Enterprise128:	ram_size = 128*1024;	break;
+				case Analyser::Static::Enterprise::Target::Model::Enterprise256:	ram_size = 256*1024;	break;
+			}
+
+			return uint8_t(0x100 - ram_size / 0x4000);
+		}
+
+	public:
+		ConcreteMachine([[maybe_unused]] const Analyser::Static::Enterprise::Target &target, const ROMMachine::ROMFetcher &rom_fetcher) :
+			min_ram_slot_(min_ram_slot(target)),
+			z80_(*this),
+			nick_(ram_.end() - 65536),
+			dave_audio_(audio_queue_),
+			speaker_(dave_audio_) {
+			// Request a clock of 4Mhz; this'll be mapped upwards for Nick and Dave elsewhere.
+			set_clock_rate(4'000'000);
+
+			ROM::Request request;
+			using Target = Analyser::Static::Enterprise::Target;
+
+			// Pick one or more EXOS ROMs.
+			switch(target.exos_version) {
+				case Target::EXOSVersion::v10:	request = request && ROM::Request(ROM::Name::EnterpriseEXOS10);	break;
+				case Target::EXOSVersion::v20:	request = request && ROM::Request(ROM::Name::EnterpriseEXOS20);	break;
+				case Target::EXOSVersion::v21:	request = request && ROM::Request(ROM::Name::EnterpriseEXOS21);	break;
+				case Target::EXOSVersion::v23:	request = request && ROM::Request(ROM::Name::EnterpriseEXOS23);	break;
+				case Target::EXOSVersion::Any:
+					request =
+						request && (
+							ROM::Request(ROM::Name::EnterpriseEXOS10) || ROM::Request(ROM::Name::EnterpriseEXOS20) ||
+							ROM::Request(ROM::Name::EnterpriseEXOS21) || ROM::Request(ROM::Name::EnterpriseEXOS23)
+						);
+				break;
+
+				default: break;
+			}
+
+			// Similarly pick one or more BASIC ROMs.
+			switch(target.basic_version) {
+				case Target::BASICVersion::v10:
+					request = request && (
+						ROM::Request(ROM::Name::EnterpriseBASIC10) ||
+						(ROM::Request(ROM::Name::EnterpriseBASIC10Part1) && ROM::Request(ROM::Name::EnterpriseBASIC10Part2))
+					);
+				break;
+				case Target::BASICVersion::v11:
+					request = request && (
+						ROM::Request(ROM::Name::EnterpriseBASIC11) ||
+						ROM::Request(ROM::Name::EnterpriseBASIC11Suffixed)
+					);
+				case Target::BASICVersion::v21:
+					request = request && ROM::Request(ROM::Name::EnterpriseBASIC21);
+				break;
+				case Target::BASICVersion::Any:
+					request =
+						request && (
+							ROM::Request(ROM::Name::EnterpriseBASIC10) ||
+							(ROM::Request(ROM::Name::EnterpriseBASIC10Part1) && ROM::Request(ROM::Name::EnterpriseBASIC10Part2)) ||
+							ROM::Request(ROM::Name::EnterpriseBASIC11) ||
+							ROM::Request(ROM::Name::EnterpriseBASIC21)
+						);
+				break;
+
+				default: break;
+			}
+
+			// Possibly add in a DOS.
+			switch(target.dos) {
+				case Target::DOS::EXDOS:			request = request && ROM::Request(ROM::Name::EnterpriseEXDOS);	break;
+				default: break;
+			}
+
+			// Get and validate ROMs.
+			auto roms = rom_fetcher(request);
+			if(!request.validate(roms)) {
+				throw ROMMachine::Error::MissingROMs;
+			}
+
+			// Extract the appropriate EXOS ROM.
+			exos_.fill(0xff);
+			for(const auto rom_name: { ROM::Name::EnterpriseEXOS10, ROM::Name::EnterpriseEXOS20, ROM::Name::EnterpriseEXOS21, ROM::Name::EnterpriseEXOS23 }) {
+				const auto exos = roms.find(rom_name);
+				if(exos != roms.end()) {
+					memcpy(exos_.data(), exos->second.data(), std::min(exos_.size(), exos->second.size()));
+					break;
+				}
+			}
+
+			// Extract the appropriate BASIC ROM[s] (if any).
+			basic_.fill(0xff);
+			bool has_basic = false;
+			for(const auto rom_name: { ROM::Name::EnterpriseBASIC10, ROM::Name::EnterpriseBASIC11, ROM::Name::EnterpriseBASIC11Suffixed, ROM::Name::EnterpriseBASIC21 }) {
+				const auto basic = roms.find(rom_name);
+				if(basic != roms.end()) {
+					memcpy(basic_.data(), basic->second.data(), std::min(basic_.size(), basic->second.size()));
+					has_basic = true;
+					break;
+				}
+			}
+			if(!has_basic) {
+				const auto basic1 = roms.find(ROM::Name::EnterpriseBASIC10Part1);
+				const auto basic2 = roms.find(ROM::Name::EnterpriseBASIC10Part2);
+				if(basic1 != roms.end() && basic2 != roms.end()) {
+					memcpy(&basic_[0x0000], basic1->second.data(), std::min(size_t(8192), basic1->second.size()));
+					memcpy(&basic_[0x2000], basic2->second.data(), std::min(size_t(8192), basic2->second.size()));
+				}
+			}
+
+			// Extract the appropriate DOS ROMs.
+			epdos_rom_.fill(0xff);
+			const auto epdos = roms.find(ROM::Name::EnterpriseEPDOS);
+			if(epdos != roms.end()) {
+				memcpy(epdos_rom_.data(), epdos->second.data(), std::min(epdos_rom_.size(), epdos->second.size()));
+			}
+			exdos_rom_.fill(0xff);
+			const auto exdos = roms.find(ROM::Name::EnterpriseEXDOS);
+			if(exdos != roms.end()) {
+				memcpy(exdos_rom_.data(), exdos->second.data(), std::min(exdos_rom_.size(), exdos->second.size()));
+			}
+
+			// Seed key state.
+			clear_all_keys();
+
+			// Take a reasonable guess at the initial memory configuration:
+			// put EXOS into the first bank since this is a Z80 and therefore
+			// starts from address 0; the third instruction in EXOS is a jump
+			// to $c02e so it's reasonable to assume EXOS is in the highest bank
+			// too, and it appears to act correctly if it's the first 16kb that's
+			// in the highest bank. From there I guess: all banks are initialised
+			// to 0.
+			page<0>(0x00);
+			page<1>(0x00);
+			page<2>(0x00);
+			page<3>(0x00);
+
+			// Set up audio.
+			speaker_.set_input_rate(250000.0f);	// TODO: a bigger number, and respect the programmable divider.
+
+			// Pass on any media.
+			insert_media(target.media);
+			if(!target.loading_command.empty()) {
+				type_string(target.loading_command);
+			}
+
+			// Ensure the splash screen is automatically skipped if any media has been provided.
+			if(!target.media.empty()) {
+				should_skip_splash_screen_ = !target.media.empty();
+				typer_delay_ = 2;
+			}
+		}
+
+		~ConcreteMachine() {
+			audio_queue_.flush();
+		}
+
+		// MARK: - Z80::BusHandler.
+		forceinline void advance_nick(HalfCycles duration) {
+			if(nick_ += duration) {
+				const auto nick = nick_.last_valid();
+				const bool nick_interrupt_line = nick->get_interrupt_line();
+				if(nick_interrupt_line && !previous_nick_interrupt_line_) {
+					set_interrupts(uint8_t(Dave::Interrupt::Nick), nick_.last_sequence_point_overrun());
+				}
+				previous_nick_interrupt_line_ = nick_interrupt_line;
+			}
+		}
+
+		forceinline HalfCycles perform_machine_cycle(const CPU::Z80::PartialMachineCycle &cycle) {
+			using PartialMachineCycle = CPU::Z80::PartialMachineCycle;
+			const uint16_t address = cycle.address ? *cycle.address : 0x0000;
+
+			// Calculate an access penalty, if applicable.
+			//
+			// Rule applied here, which is slightly inferred:
+			//
+			//	Non-video reads and writes are delayed by exactly a cycle or not delayed at all,
+			//	depending on the programmer's configuration of Dave.
+			//
+			//	Video reads and writes, and Nick port accesses, are delayed so that the last
+			//	clock cycle of the machine cycle falls wholly inside the designated Z80 access
+			//	window, per Nick.
+			//
+			// The switch statement below just attempts to implement that logic.
+			//
+			HalfCycles penalty;
+			switch(cycle.operation) {
+				default: break;
+
+				// For non-video pauses, insert during the initial part of the bus cycle.
+				case CPU::Z80::PartialMachineCycle::ReadStart:
+				case CPU::Z80::PartialMachineCycle::WriteStart:
+					if(!is_video_[address >> 14] && wait_mode_ == WaitMode::OnAllAccesses) {
+						penalty = HalfCycles(2);
+					}
+				break;
+				case CPU::Z80::PartialMachineCycle::ReadOpcodeStart:
+					if(!is_video_[address >> 14] && wait_mode_ != WaitMode::None) {
+						penalty = HalfCycles(2);
+					} else {
+						// Query Nick for the amount of delay that would occur with one cycle left
+						// in this read opcode.
+						const auto delay_time = nick_.time_since_flush(HalfCycles(2));
+						const auto delay = nick_.last_valid()->get_time_until_z80_slot(delay_time);
+						penalty = nick_.back_map(delay, delay_time);
+					}
+				break;
+
+				// Video pauses: insert right at the end of the bus cycle.
+				case CPU::Z80::PartialMachineCycle::Write:
+					// Ensure all video that should have been collected prior to
+					// this write has been.
+					if(is_video_[address >> 14]) {
+						nick_.flush();
+					}
+					[[fallthrough]];
+
+				case CPU::Z80::PartialMachineCycle::Read:
+					if(is_video_[address >> 14]) {
+						// Get delay, in Nick cycles, for a Z80 access that occurs in 0.5
+						// cycles from now (i.e. with one cycle left to run).
+						const auto delay_time = nick_.time_since_flush(HalfCycles(1));
+						const auto delay = nick_.last_valid()->get_time_until_z80_slot(delay_time);
+						penalty = nick_.back_map(delay, delay_time);
+					}
+				break;
+
+				case CPU::Z80::PartialMachineCycle::Input:
+				case CPU::Z80::PartialMachineCycle::Output: {
+					if((address & 0xf0) == 0x80) {
+						// Get delay, in Nick cycles, for a Z80 access that occurs in 0.5
+						// cycles from now (i.e. with one cycle left to run).
+						const auto delay_time = nick_.time_since_flush(HalfCycles(1));
+						const auto delay = nick_.last_valid()->get_time_until_z80_slot(delay_time);
+						penalty = nick_.back_map(delay, delay_time);
+					}
+				}
+			}
+
+			const HalfCycles full_length = cycle.length + penalty;
+			time_since_audio_update_ += full_length;
+			advance_nick(full_length);
+			if(dave_timer_ += full_length) {
+				set_interrupts(dave_timer_.last_valid()->get_new_interrupts(), dave_timer_.last_sequence_point_overrun());
+			}
+
+			// The WD/etc runs at a nominal 8Mhz.
+			if constexpr (has_disk_controller) {
+				exdos_.run_for(Cycles(full_length.as_integral()));
+			}
+
+			switch(cycle.operation) {
+				default: break;
+
+				case CPU::Z80::PartialMachineCycle::Input:
+					switch(address & 0xff) {
+						default:
+							LOG("Unhandled input from " << PADHEX(2) << (address & 0xff));
+							*cycle.value = 0xff;
+						break;
+
+						case 0x10:	case 0x11:	case 0x12:	case 0x13:
+						case 0x14:	case 0x15:	case 0x16:	case 0x17:
+							if constexpr (has_disk_controller) {
+								*cycle.value = exdos_.read(address);
+							} else {
+								*cycle.value = 0xff;
+							}
+						break;
+						case 0x18:	case 0x19:	case 0x1a:	case 0x1b:
+						case 0x1c:	case 0x1d:	case 0x1e:	case 0x1f:
+							if constexpr (has_disk_controller) {
+								*cycle.value = exdos_.get_control_register();
+							} else {
+								*cycle.value = 0xff;
+							}
+						break;
+
+						case 0x80:	case 0x81:	case 0x82:	case 0x83:
+						case 0x84:	case 0x85:	case 0x86:	case 0x87:
+						case 0x88:	case 0x89:	case 0x8a:	case 0x8b:
+						case 0x8c:	case 0x8d:	case 0x8e:	case 0x8f:
+							*cycle.value = nick_->read();
+						break;
+
+						case 0xb0:	*cycle.value = pages_[0];	break;
+						case 0xb1:	*cycle.value = pages_[1];	break;
+						case 0xb2:	*cycle.value = pages_[2];	break;
+						case 0xb3:	*cycle.value = pages_[3];	break;
+
+						case 0xb4:
+							*cycle.value =
+								(nick_->get_interrupt_line() ? 0x00 : 0x10) |
+								dave_timer_->get_divider_state() |
+								interrupt_state_;
+						break;
+						case 0xb5:
+							if(active_key_line_ < key_lines_.size()) {
+								*cycle.value = key_lines_[active_key_line_];
+							} else {
+								*cycle.value = 0xff;
+							}
+						break;
+						case 0xb6: {
+							// TODO: selected keyboard row, 0 to 9, should return one bit of joystick
+							// input. That being the case:
+							//
+							//	b0:		joystick input
+							//	b1, b2:	unused (in theory read from control port, but not used by any hardware)
+							//	b3:		0 = printer ready; 1 = not ready
+							//	b4:		serial, data in
+							//	b5:		serial, status in
+							//	b6:		tape input volume level, 0 = high, 1 = low
+							//	b7:		tape data input
+							*cycle.value = 0xff;
+						} break;
+					}
+				break;
+
+				case CPU::Z80::PartialMachineCycle::Output:
+					switch(address & 0xff) {
+						default:
+							LOG("Unhandled output: " << PADHEX(2) << *cycle.value << " to " << PADHEX(2) << (address & 0xff));
+						break;
+
+						case 0x10:	case 0x11:	case 0x12:	case 0x13:
+						case 0x14:	case 0x15:	case 0x16:	case 0x17:
+							if constexpr(has_disk_controller) {
+								exdos_.write(address, *cycle.value);
+							}
+						break;
+						case 0x18:	case 0x19:	case 0x1a:	case 0x1b:
+						case 0x1c:	case 0x1d:	case 0x1e:	case 0x1f:
+							if constexpr(has_disk_controller) {
+								exdos_.set_control_register(*cycle.value);
+							}
+						break;
+
+						case 0x80:	case 0x81:	case 0x82:	case 0x83:
+						case 0x84:	case 0x85:	case 0x86:	case 0x87:
+						case 0x88:	case 0x89:	case 0x8a:	case 0x8b:
+						case 0x8c:	case 0x8d:	case 0x8e:	case 0x8f:
+							nick_->write(address, *cycle.value);
+						break;
+
+						case 0xb0:	page<0>(*cycle.value);	break;
+						case 0xb1:	page<1>(*cycle.value);	break;
+						case 0xb2:	page<2>(*cycle.value);	break;
+						case 0xb3:	page<3>(*cycle.value);	break;
+
+						case 0xa0:	case 0xa1:	case 0xa2:	case 0xa3:
+						case 0xa4:	case 0xa5:	case 0xa6:	case 0xa7:
+						case 0xa8:	case 0xa9:	case 0xaa:	case 0xab:
+						case 0xac:	case 0xad:	case 0xae:	case 0xaf:
+							update_audio();
+							dave_audio_.write(address, *cycle.value);
+							dave_timer_->write(address, *cycle.value);
+						break;
+
+						case 0xb4:
+							interrupt_mask_ = *cycle.value & 0x55;
+							interrupt_state_ &= ~*cycle.value;
+							update_interrupts();
+						break;
+						case 0xb5:
+							// Logic here: the ROM scans the keyboard by checking ascending
+							// lines. It also seems to provide a line of 0 when using port B5
+							// for non-keyboard uses.
+							//
+							// So: use the rollover from line 9 back to line 0 as a trigger to
+							// spot that a scan of the keyboard just finished. Which makes it
+							// time to enqueue the next keypress.
+							//
+							// Re: should_skip_splash_screen_ and typer_delay_, assume that a
+							// single keypress is necessary to get past the Enterprise splash
+							// screen, then a pause in keypressing while BASIC or whatever
+							// starts up, then presses can resume.
+							if(active_key_line_ == 9 && !(*cycle.value & 0xf) && (should_skip_splash_screen_ || typer_)) {
+								if(should_skip_splash_screen_) {
+									set_key_state(uint16_t(Key::Space), typer_delay_);
+									if(typer_delay_) {
+										--typer_delay_;
+									} else {
+										typer_delay_ = 60;
+										should_skip_splash_screen_ = false;
+									}
+								} else {
+									if(!typer_delay_) {
+										if(!typer_->type_next_character()) {
+											clear_all_keys();
+											typer_ = nullptr;
+										}
+									} else {
+										--typer_delay_;
+									}
+								}
+							}
+
+							active_key_line_ = *cycle.value & 0xf;
+							// TODO:
+							//
+							//	b4:	strobe output for printer
+							//	b5:	tape sound control (?)
+							//	b6:	tape motor control 1, 1 = on
+							//	b7: tape motor control 2, 1 = on
+						break;
+						case 0xb6:
+							// Just 8 bits of printer data.
+							LOG("TODO: printer output " << PADHEX(2) << *cycle.value);
+						break;
+						case 0xb7:
+							// b0 = serial data out
+							// b1 = serial status out
+							LOG("TODO: serial output " << PADHEX(2) << *cycle.value);
+						break;
+						case 0xbf:
+							// TODO: onboard RAM, Dave 8/12Mhz select.
+							switch((*cycle.value >> 2)&3) {
+								default:	wait_mode_ = WaitMode::None;			break;
+								case 0:		wait_mode_ = WaitMode::OnAllAccesses;	break;
+								case 1:		wait_mode_ = WaitMode::OnM1;			break;
+							}
+						break;
+					}
+				break;
+
+				case CPU::Z80::PartialMachineCycle::Read:
+				case CPU::Z80::PartialMachineCycle::ReadOpcode:
+					if(read_pointers_[address >> 14]) {
+						*cycle.value = read_pointers_[address >> 14][address];
+					} else {
+						*cycle.value = 0xff;
+					}
+				break;
+
+				case CPU::Z80::PartialMachineCycle::Write:
+					if(write_pointers_[address >> 14]) {
+						write_pointers_[address >> 14][address] = *cycle.value;
+					}
+				break;
+			}
+
+			return penalty;
+		}
+
+		void flush() {
+			nick_.flush();
+			update_audio();
+			audio_queue_.perform();
+		}
+
+	private:
+		// MARK: - Memory layout
+		std::array<uint8_t, 256 * 1024> ram_{};
+		std::array<uint8_t, 64 * 1024> exos_;
+		std::array<uint8_t, 16 * 1024> basic_;
+		std::array<uint8_t, 16 * 1024> exdos_rom_;
+		std::array<uint8_t, 32 * 1024> epdos_rom_;
+		const uint8_t min_ram_slot_;
+
+		const uint8_t *read_pointers_[4] = {nullptr, nullptr, nullptr, nullptr};
+		uint8_t *write_pointers_[4] = {nullptr, nullptr, nullptr, nullptr};
+		uint8_t pages_[4] = {0x80, 0x80, 0x80, 0x80};
+
+		template <size_t slot> void page(uint8_t offset) {
+			pages_[slot] = offset;
+
+#define Map(location, source)												\
+	if(offset >= location && offset < location + source.size() / 0x4000) {	\
+		page<slot>(&source[(offset - location) * 0x4000], nullptr);			\
+		is_video_[slot] = false;											\
+		return;																\
+	}
+
+			Map(0, exos_);
+			Map(16, basic_);
+			Map(32, exdos_rom_);
+			Map(48, epdos_rom_);
+
+#undef Map
+
+			// Of whatever size of RAM I've declared above, use only the final portion.
+			// This correlated with Nick always having been handed the final 64kb and,
+			// at least while the RAM is the first thing declared above, does a little
+			// to benefit data locality. Albeit not in a useful sense.
+			if(offset >= min_ram_slot_) {
+				const auto ram_floor = 4194304 - ram_.size();
+				const size_t address = offset * 0x4000 - ram_floor;
+				is_video_[slot] = offset >= 0xfc;	// TODO: this hard-codes a 64kb video assumption.
+				page<slot>(&ram_[address], &ram_[address]);
+				return;
+			}
+
+			page<slot>(nullptr, nullptr);
+		}
+
+		template <size_t slot> void page(const uint8_t *read, uint8_t *write) {
+			read_pointers_[slot] = read ? read - (slot * 0x4000) : nullptr;
+			write_pointers_[slot] = write ? write - (slot * 0x4000) : nullptr;
+		}
+
+		// MARK: - Memory Timing
+
+		// The wait mode affects all memory accesses _outside of the video area_.
+		enum class WaitMode {
+			None,
+			OnM1,
+			OnAllAccesses
+		} wait_mode_ = WaitMode::None;
+		bool is_video_[4]{};
+
+		// MARK: - ScanProducer
+		void set_scan_target(Outputs::Display::ScanTarget *scan_target) override {
+			nick_.last_valid()->set_scan_target(scan_target);
+		}
+
+		Outputs::Display::ScanStatus get_scaled_scan_status() const override {
+			return nick_.last_valid()->get_scaled_scan_status();
+		}
+
+		void set_display_type(Outputs::Display::DisplayType display_type) final {
+			nick_.last_valid()->set_display_type(display_type);
+		}
+
+		Outputs::Display::DisplayType get_display_type() const final {
+			return nick_.last_valid()->get_display_type();
+		}
+
+		// MARK: - AudioProducer
+
+		Outputs::Speaker::Speaker *get_speaker() final {
+			return &speaker_;
+		}
+
+		// MARK: - TimedMachine
+		void run_for(const Cycles cycles) override {
+			z80_.run_for(cycles);
+		}
+
+		// MARK: - KeyboardMachine
+		Enterprise::KeyboardMapper keyboard_mapper_;
+		KeyboardMapper *get_keyboard_mapper() final {
+			return &keyboard_mapper_;
+		}
+
+		uint8_t active_key_line_ = 0;
+		std::array<uint8_t, 10> key_lines_;
+		void set_key_state(uint16_t key, bool is_pressed) final {
+			if(is_pressed) {
+				key_lines_[key >> 8] &= ~uint8_t(key);
+			} else {
+				key_lines_[key >> 8] |= uint8_t(key);
+			}
+		}
+
+		void clear_all_keys() final {
+			key_lines_.fill(0xff);
+		}
+
+		// MARK: - Utility::TypeRecipient
+		void type_string(const std::string &string) final {
+			Utility::TypeRecipient<CharacterMapper>::add_typer(string);
+
+			if(z80_.get_is_resetting()) {
+				should_skip_splash_screen_ = true;
+				typer_delay_ = 1;
+			} else {
+				should_skip_splash_screen_ = false;
+				typer_delay_ = 0;
+			}
+		}
+
+		bool can_type(char c) const final {
+			return Utility::TypeRecipient<CharacterMapper>::can_type(c);
+		}
+
+		bool should_skip_splash_screen_ = false;
+		int typer_delay_ = 30;
+
+		// MARK: - MediaTarget
+		bool insert_media(const Analyser::Static::Media &media) final {
+			if constexpr (has_disk_controller) {
+				if(!media.disks.empty()) {
+					exdos_.set_disk(media.disks.front(), 0);
+				}
+			}
+
+			return true;
+		}
+
+		// MARK: - Interrupts
+
+		uint8_t interrupt_mask_ = 0x00, interrupt_state_ = 0x00;
+		void set_interrupts(uint8_t mask, HalfCycles offset = HalfCycles(0)) {
+			interrupt_state_ |= uint8_t(mask);
+			update_interrupts(offset);
+		}
+		void update_interrupts(HalfCycles offset = HalfCycles(0)) {
+			z80_.set_interrupt_line((interrupt_state_ >> 1) & interrupt_mask_, offset);
+		}
+
+		// MARK: - Chips.
+		CPU::Z80::Processor<ConcreteMachine, false, false> z80_;
+		JustInTimeActor<Nick, HalfCycles, 40434603, 11360000> nick_;
+		bool previous_nick_interrupt_line_ = false;
+		// Cf. timing guesses above.
+
+		Concurrency::DeferringAsyncTaskQueue audio_queue_;
+		Dave::Audio dave_audio_;
+		Outputs::Speaker::LowpassSpeaker<Dave::Audio> speaker_;
+		HalfCycles time_since_audio_update_;
+
+		// The following two should both use the same divider.
+		JustInTimeActor<Dave::TimedInterruptSource, HalfCycles, 1, 16> dave_timer_;
+		inline void update_audio() {
+			// TODO: divide by only 8, letting Dave divide itself by a further 2 or 3
+			// as per its own register.
+			speaker_.run_for(audio_queue_, time_since_audio_update_.divide_cycles(Cycles(16)));
+		}
+
+		// MARK: - EXDos card.
+		EXDos exdos_;
+
+		// MARK: - Activity Source
+		void set_activity_observer(Activity::Observer *observer) final {
+			if constexpr (has_disk_controller) {
+				exdos_.set_activity_observer(observer);
+			}
+		}
+
+		// MARK: - Configuration options.
+		std::unique_ptr<Reflection::Struct> get_options() final {
+			auto options = std::make_unique<Options>(Configurable::OptionsType::UserFriendly);
+			options->output = get_video_signal_configurable();
+			return options;
+		}
+
+		void set_options(const std::unique_ptr<Reflection::Struct> &str) final {
+			const auto options = dynamic_cast<Options *>(str.get());
+			set_video_signal_configurable(options->output);
+		}
+};
+
+}
+
+using namespace Enterprise;
+
+Machine *Machine::Enterprise(const Analyser::Static::Target *target, const ROMMachine::ROMFetcher &rom_fetcher) {
+	using Target = Analyser::Static::Enterprise::Target;
+	const Target *const enterprise_target = dynamic_cast<const Target *>(target);
+
+	if(enterprise_target->dos == Target::DOS::None)
+		return new Enterprise::ConcreteMachine<false>(*enterprise_target, rom_fetcher);
+	else
+		return new Enterprise::ConcreteMachine<true>(*enterprise_target, rom_fetcher);
+}
+
+Machine::~Machine() {}

Machines/Enterprise/Enterprise.hpp

@@ -0,0 +1,47 @@
+//
+//  Enterprise.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 10/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#ifndef Enterprise_hpp
+#define Enterprise_hpp
+
+#include "../../Analyser/Static/StaticAnalyser.hpp"
+#include "../../Configurable/Configurable.hpp"
+#include "../../Configurable/StandardOptions.hpp"
+#include "../ROMMachine.hpp"
+
+namespace Enterprise {
+
+/*!
+	@abstract Represents an Elan Enterprise.
+
+	@discussion An instance of Enterprise::Machine represents the current state of an
+	Elan Enterprise.
+*/
+class Machine {
+	public:
+		virtual ~Machine();
+
+		static Machine *Enterprise(const Analyser::Static::Target *target, const ROMMachine::ROMFetcher &rom_fetcher);
+
+		/// Defines the runtime options available for an Enterprise.
+		class Options: public Reflection::StructImpl<Options>, public Configurable::DisplayOption<Options> {
+			friend Configurable::DisplayOption<Options>;
+			public:
+				Options(Configurable::OptionsType type) :
+					Configurable::DisplayOption<Options>(type == Configurable::OptionsType::UserFriendly ? Configurable::Display::RGB : Configurable::Display::CompositeColour) {
+					if(needs_declare()) {
+						declare_display_option();
+						limit_enum(&output, Configurable::Display::RGB, Configurable::Display::CompositeColour, Configurable::Display::CompositeMonochrome, -1);
+					}
+				}
+		};
+};
+
+};
+
+#endif /* Enterprise_hpp */

Machines/Enterprise/Keyboard.cpp

@@ -0,0 +1,151 @@
+//
+//  Keyboard.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 17/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#include "Keyboard.hpp"
+
+using namespace Enterprise;
+
+uint16_t KeyboardMapper::mapped_key_for_key(Inputs::Keyboard::Key key) const {
+#define BIND(source, dest)	case Inputs::Keyboard::Key::source:	return uint16_t(Key::dest)
+	switch(key) {
+		default: break;
+
+		BIND(Backslash, Backslash);
+		BIND(CapsLock, Lock);
+		BIND(Tab, Tab);
+		BIND(Escape, Escape);
+		BIND(Hyphen, Hyphen);
+		BIND(Equals, Caret);
+		BIND(Backspace, Erase);
+		BIND(Delete, Delete);
+		BIND(Semicolon, Semicolon);
+		BIND(Quote, Colon);
+		BIND(OpenSquareBracket, OpenSquareBracket);
+		BIND(CloseSquareBracket, CloseSquareBracket);
+
+		BIND(End, Stop);
+		BIND(Insert, Insert);
+		BIND(BackTick, At);
+
+		BIND(k1, k1);	BIND(k2, k2);	BIND(k3, k3);	BIND(k4, k4);	BIND(k5, k5);
+		BIND(k6, k6);	BIND(k7, k7);	BIND(k8, k8);	BIND(k9, k9);	BIND(k0, k0);
+
+		BIND(F1, F1);	BIND(F2, F2);	BIND(F3, F3);	BIND(F4, F4);
+		BIND(F5, F5);	BIND(F6, F6);	BIND(F7, F7);	BIND(F8, F8);
+
+		BIND(Keypad1, F1);	BIND(Keypad2, F2);	BIND(Keypad3, F3);	BIND(Keypad4, F4);
+		BIND(Keypad5, F5);	BIND(Keypad6, F6);	BIND(Keypad7, F7);	BIND(Keypad8, F8);
+
+		BIND(Q, Q);	BIND(W, W);	BIND(E, E);	BIND(R, R);	BIND(T, T);
+		BIND(Y, Y);	BIND(U, U);	BIND(I, I);	BIND(O, O);	BIND(P, P);
+
+		BIND(A, A);	BIND(S, S);	BIND(D, D);	BIND(F, F);	BIND(G, G);
+		BIND(H, H);	BIND(J, J);	BIND(K, K);	BIND(L, L);
+
+		BIND(Z, Z);	BIND(X, X);	BIND(C, C);	BIND(V, V);
+		BIND(B, B);	BIND(N, N);	BIND(M, M);
+
+		BIND(FullStop, FullStop);
+		BIND(Comma, Comma);
+		BIND(ForwardSlash, ForwardSlash);
+
+		BIND(Space, Space);	BIND(Enter, Enter);
+
+		BIND(LeftShift, LeftShift);
+		BIND(RightShift, RightShift);
+		BIND(LeftOption, Alt);
+		BIND(RightOption, Alt);
+		BIND(LeftControl, Control);
+		BIND(RightControl, Control);
+
+		BIND(Left, Left);
+		BIND(Right, Right);
+		BIND(Up, Up);
+		BIND(Down, Down);
+	}
+#undef BIND
+
+	return MachineTypes::MappedKeyboardMachine::KeyNotMapped;
+}
+
+const uint16_t *CharacterMapper::sequence_for_character(char character) const {
+#define KEYS(x)		{uint16_t(x), MachineTypes::MappedKeyboardMachine::KeyEndSequence}
+#define SHIFT(x)	{uint16_t(Key::LeftShift), uint16_t(x), MachineTypes::MappedKeyboardMachine::KeyEndSequence}
+#define _			{MachineTypes::MappedKeyboardMachine::KeyNotMapped}
+	static KeySequence key_sequences[] = {
+		/* NUL */	_,							/* SOH */	_,
+		/* STX */	_,							/* ETX */	_,
+		/* EOT */	_,							/* ENQ */	_,
+		/* ACK */	_,							/* BEL */	_,
+		/* BS */	KEYS(Key::Erase),			/* HT */	KEYS(Key::Tab),
+		/* LF */	KEYS(Key::Enter),			/* VT */	_,
+		/* FF */	_,							/* CR */	KEYS(Key::Enter),
+		/* SO */	_,							/* SI */	_,
+		/* DLE */	_,							/* DC1 */	_,
+		/* DC2 */	_,							/* DC3 */	_,
+		/* DC4 */	_,							/* NAK */	_,
+		/* SYN */	_,							/* ETB */	_,
+		/* CAN */	_,							/* EM */	_,
+		/* SUB */	_,							/* ESC */	KEYS(Key::Escape),
+		/* FS */	_,							/* GS */	_,
+		/* RS */	_,							/* US */	_,
+		/* space */	KEYS(Key::Space),			/* ! */		SHIFT(Key::k1),
+		/* " */		SHIFT(Key::k2),				/* # */		_,
+		/* $ */		SHIFT(Key::k4),				/* % */		SHIFT(Key::k5),
+		/* & */		SHIFT(Key::k6),				/* ' */		SHIFT(Key::k7),
+		/* ( */		SHIFT(Key::k8),				/* ) */		SHIFT(Key::k9),
+		/* * */		SHIFT(Key::Colon),			/* + */		SHIFT(Key::Semicolon),
+		/* , */		KEYS(Key::Comma),			/* - */		KEYS(Key::Hyphen),
+		/* . */		KEYS(Key::FullStop),		/* / */		KEYS(Key::ForwardSlash),
+		/* 0 */		KEYS(Key::k0),				/* 1 */		KEYS(Key::k1),
+		/* 2 */		KEYS(Key::k2),				/* 3 */		KEYS(Key::k3),
+		/* 4 */		KEYS(Key::k4),				/* 5 */		KEYS(Key::k5),
+		/* 6 */		KEYS(Key::k6),				/* 7 */		KEYS(Key::k7),
+		/* 8 */		KEYS(Key::k8),				/* 9 */		KEYS(Key::k9),
+		/* : */		KEYS(Key::Colon),			/* ; */		KEYS(Key::Semicolon),
+		/* < */		SHIFT(Key::Comma),			/* = */		SHIFT(Key::Hyphen),
+		/* > */		SHIFT(Key::FullStop),		/* ? */		SHIFT(Key::ForwardSlash),
+		/* @ */		KEYS(Key::At),				/* A */		SHIFT(Key::A),
+		/* B */		SHIFT(Key::B),				/* C */		SHIFT(Key::C),
+		/* D */		SHIFT(Key::D),				/* E */		SHIFT(Key::E),
+		/* F */		SHIFT(Key::F),				/* G */		SHIFT(Key::G),
+		/* H */		SHIFT(Key::H),				/* I */		SHIFT(Key::I),
+		/* J */		SHIFT(Key::J),				/* K */		SHIFT(Key::K),
+		/* L */		SHIFT(Key::L),				/* M */		SHIFT(Key::M),
+		/* N */		SHIFT(Key::N),				/* O */		SHIFT(Key::O),
+		/* P */		SHIFT(Key::P),				/* Q */		SHIFT(Key::Q),
+		/* R */		SHIFT(Key::R),				/* S */		SHIFT(Key::S),
+		/* T */		SHIFT(Key::T),				/* U */		SHIFT(Key::U),
+		/* V */		SHIFT(Key::V),				/* W */		SHIFT(Key::W),
+		/* X */		SHIFT(Key::X),				/* Y */		SHIFT(Key::Y),
+		/* Z */		SHIFT(Key::Z),				/* [ */		KEYS(Key::OpenSquareBracket),
+		/* \ */		KEYS(Key::Backslash),		/* ] */		KEYS(Key::CloseSquareBracket),
+		/* ^ */		SHIFT(Key::Caret),			/* _ */		SHIFT(Key::k0),
+		/* ` */		SHIFT(Key::At),				/* a */		KEYS(Key::A),
+		/* b */		KEYS(Key::B),				/* c */		KEYS(Key::C),
+		/* d */		KEYS(Key::D),				/* e */		KEYS(Key::E),
+		/* f */		KEYS(Key::F),				/* g */		KEYS(Key::G),
+		/* h */		KEYS(Key::H),				/* i */		KEYS(Key::I),
+		/* j */		KEYS(Key::J),				/* k */		KEYS(Key::K),
+		/* l */		KEYS(Key::L),				/* m */		KEYS(Key::M),
+		/* n */		KEYS(Key::N),				/* o */		KEYS(Key::O),
+		/* p */		KEYS(Key::P),				/* q */		KEYS(Key::Q),
+		/* r */		KEYS(Key::R),				/* s */		KEYS(Key::S),
+		/* t */		KEYS(Key::T),				/* u */		KEYS(Key::U),
+		/* v */		KEYS(Key::V),				/* w */		KEYS(Key::W),
+		/* x */		KEYS(Key::X),				/* y */		KEYS(Key::Y),
+		/* z */		KEYS(Key::Z),				/* { */		SHIFT(Key::OpenSquareBracket),
+		/* | */		SHIFT(Key::Backslash),		/* } */		SHIFT(Key::CloseSquareBracket),
+		/* ~ */		SHIFT(Key::Caret)
+	};
+#undef _
+#undef SHIFT
+#undef KEYS
+
+	return table_lookup_sequence_for_character(key_sequences, character);
+}

Machines/Enterprise/Keyboard.hpp

@@ -0,0 +1,66 @@
+//
+//  Keyboard.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 17/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#ifndef Machines_Enterprise_Keyboard_hpp
+#define Machines_Enterprise_Keyboard_hpp
+
+#include "../KeyboardMachine.hpp"
+#include "../Utility/Typer.hpp"
+
+namespace Enterprise {
+
+#define KeyCode(line, mask)	(line << 8) | mask
+
+enum class Key: uint16_t {
+	N		= 0x0000 | 0x01,	Backslash	= 0x0000 | 0x02,	B		= 0x0000 | 0x04,	C			= 0x0000 | 0x08,
+	V		= 0x0000 | 0x10,	X 			= 0x0000 | 0x20,	Z		= 0x0000 | 0x40,	LeftShift	= 0x0000 | 0x80,
+
+	H		= 0x0100 | 0x01,	Lock		= 0x0100 | 0x02,	G		= 0x0100 | 0x04,	D			= 0x0100 | 0x08,
+	F		= 0x0100 | 0x10,	S			= 0x0100 | 0x20,	A		= 0x0100 | 0x40,	Control		= 0x0100 | 0x80,
+
+	U		= 0x0200 | 0x01,	Q			= 0x0200 | 0x02,	Y		= 0x0200 | 0x04,	R			= 0x0200 | 0x08,
+	T		= 0x0200 | 0x10,	E			= 0x0200 | 0x20,	W		= 0x0200 | 0x40,	Tab			= 0x0200 | 0x80,
+
+	k7		= 0x0300 | 0x01,	k1			= 0x0300 | 0x02,	k6		= 0x0300 | 0x04,	k4			= 0x0300 | 0x08,
+	k5		= 0x0300 | 0x10,	k3			= 0x0300 | 0x20,	k2		= 0x0300 | 0x40,	Escape		= 0x0300 | 0x80,
+
+	F4		= 0x0400 | 0x01,	F8			= 0x0400 | 0x02,	F3		= 0x0400 | 0x04,	F6			= 0x0400 | 0x08,
+	F5		= 0x0400 | 0x10,	F7			= 0x0400 | 0x20,	F2		= 0x0400 | 0x40,	F1			= 0x0400 | 0x80,
+
+	k8		= 0x0500 | 0x01,									k9		= 0x0500 | 0x04,	Hyphen		= 0x0500 | 0x08,
+	k0		= 0x0500 | 0x10,	Caret		= 0x0500 | 0x20,	Erase	= 0x0500 | 0x40,
+
+	J		= 0x0600 | 0x01,									K		= 0x0600 | 0x04,	Semicolon	= 0x0600 | 0x08,
+	L		= 0x0600 | 0x10,	Colon		= 0x0600 | 0x20,	CloseSquareBracket		= 0x0600 | 0x40,
+
+	Stop	= 0x0700 | 0x01,	Down		= 0x0700 | 0x02,	Right	= 0x0700 | 0x04,	Up			= 0x0700 | 0x08,
+	Hold	= 0x0700 | 0x10,	Left		= 0x0700 | 0x20,	Enter	= 0x0700 | 0x40,	Alt			= 0x0700 | 0x80,
+
+	M		= 0x0800 | 0x01,	Delete		= 0x0800 | 0x02,	Comma	= 0x0800 | 0x04,
+	ForwardSlash	= 0x0800 | 0x08,
+	FullStop		= 0x0800 | 0x10,
+								RightShift	= 0x0800 | 0x20,	Space	= 0x0800 | 0x40,	Insert		= 0x0800 | 0x80,
+
+	I		= 0x0900 | 0x01,									O		= 0x0900 | 0x04,	At			= 0x0900 | 0x08,
+	P		= 0x0900 | 0x10,
+	OpenSquareBracket		= 0x0900 | 0x20
+};
+
+#undef KeyCode
+
+struct KeyboardMapper: public MachineTypes::MappedKeyboardMachine::KeyboardMapper {
+	uint16_t mapped_key_for_key(Inputs::Keyboard::Key key) const final;
+};
+
+struct CharacterMapper: public ::Utility::CharacterMapper {
+	const uint16_t *sequence_for_character(char character) const override;
+};
+
+}
+
+#endif /* Keyboard_hpp */

Machines/Enterprise/Nick.cpp

@@ -0,0 +1,629 @@
+//
+//  Nick.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 14/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#include "Nick.hpp"
+
+#include <cstdio>
+
+namespace  {
+
+uint16_t mapped_colour(uint8_t source) {
+	// On the Enterprise, red and green are 3-bit quantities; blue is a 2-bit quantity.
+	int red		= ((source&0x01) << 2) | ((source&0x08) >> 2) | ((source&0x40) >> 6);
+	int green	= ((source&0x02) << 1) | ((source&0x10) >> 3) | ((source&0x80) >> 7);
+	int blue	= ((source&0x04) >> 1) | ((source&0x20) >> 5);
+
+	assert(red <= 7);
+	assert(green <= 7);
+	assert(blue <= 3);
+
+	red = (red << 1) + (red >> 3);
+	green = (green << 1) + (green >> 3);
+	blue = (blue << 2) + blue;
+
+	assert(red <= 15);
+	assert(green <= 15);
+	assert(blue <= 15);
+
+	// Duplicate bits where necessary to map to a full 4-bit range per channel.
+	const uint8_t parts[2] = {
+		uint8_t(
+			red
+		),
+		uint8_t(
+			(green << 4) + blue
+		)
+	};
+	return *reinterpret_cast<const uint16_t *>(parts);
+}
+
+}
+
+using namespace Enterprise;
+
+Nick::Nick(const uint8_t *ram) :
+	crt_(57*16, 16, Outputs::Display::Type::PAL50, Outputs::Display::InputDataType::Red4Green4Blue4),
+	ram_(ram) {
+
+	// Just use RGB for now.
+	set_display_type(Outputs::Display::DisplayType::RGB);
+
+	// Crop to the centre 90% of the display.
+	crt_.set_visible_area(Outputs::Display::Rect(0.05f, 0.05f, 0.9f, 0.9f));
+}
+
+void Nick::write(uint16_t address, uint8_t value) {
+	switch(address & 3) {
+		case 0:
+			// Ignored: everything to do with external colour.
+			for(int c = 0; c < 8; c++) {
+				palette_[c + 8] = mapped_colour(uint8_t(((value & 0x1f) << 3) + c));
+			}
+		break;
+		case 1:
+			if(output_type_ == OutputType::Border) {
+				set_output_type(OutputType::Border, true);
+			}
+			border_colour_ = mapped_colour(value);
+		break;
+		case 2:
+			line_parameter_base_ = uint16_t((line_parameter_base_ & 0xf000) | (value << 4));
+		break;
+		case 3:
+			line_parameter_base_ = uint16_t((line_parameter_base_ & 0x0ff0) | (value << 12));
+
+			// Still a mystery to me: the exact meaning of the top two bits here. For now
+			// just treat a 0 -> 1 transition of the MSB as a forced frame restart.
+			if((value^line_parameter_control_) & value & 0x80) {
+				// For now: just force this to be the final line of this mode block.
+				// I'm unclear whether I should also reset the horizontal counter
+				// (i.e. completely abandon current video phase).
+				lines_remaining_ = 0xff;
+				should_reload_line_parameters_ = true;
+			}
+			line_parameter_control_ = value & 0xc0;
+		break;
+	}
+}
+
+uint8_t Nick::read() {
+	return last_read_;
+}
+
+Cycles Nick::get_time_until_z80_slot(Cycles after_period) const {
+	// Place Z80 accesses in the first six cycles in each sixteen-cycle window.
+	// That models video accesses as being the final ten. Which has the net effect
+	// of responding to the line parameter table interrupt flag as soon as it's
+	// loaded.
+
+	// Assumed below: the Z80 can start its final cycle anywhere in the first three
+	// of the permitted six.
+	const int offset = (horizontal_counter_ + after_period.as<int>()) & 15;
+	if(offset < 3) {
+		return 0;
+	} else {
+		return 16 - offset;
+	}
+}
+
+void Nick::run_for(Cycles duration) {
+	constexpr int line_length = 912;
+
+#define add_window(x)															\
+	line_data_pointer_[0] += is_sync_or_pixels_ * line_data_per_column_increments_[0] * (x);	\
+	line_data_pointer_[1] += is_sync_or_pixels_ * line_data_per_column_increments_[1] * (x);	\
+	window += x;																\
+	if(window != 57 && window == left_margin_) is_sync_or_pixels_ = true;		\
+	if(window != 57 && window == right_margin_) is_sync_or_pixels_ = false;
+
+	int clocks_remaining = duration.as<int>();
+	while(clocks_remaining) {
+		// Determine how many cycles are left this line.
+		const int clocks_this_line = std::min(clocks_remaining, line_length - horizontal_counter_);
+
+		// Convert that into a [start/current] and end window.
+		int window = horizontal_counter_ >> 4;
+		const int end_window = (horizontal_counter_ + clocks_this_line) >> 4;
+
+		// Advance the line counters.
+		clocks_remaining -= clocks_this_line;
+		horizontal_counter_ = (horizontal_counter_ + clocks_this_line) % line_length;
+
+		// Do nothing if a window boundary isn't crossed.
+		if(window == end_window) continue;
+
+		// HSYNC is signalled for four windows at the start of the line.
+		// I currently believe this happens regardless of Vsync mode.
+		if(!window) {
+			set_output_type(OutputType::Sync);
+
+			// There's no increment to get to 0, it happens when the horizontal_counter_
+			// is reset. So test for active bit effect manually.
+			if(!left_margin_) is_sync_or_pixels_ = true;
+			if(!right_margin_) is_sync_or_pixels_ = false;
+		}
+
+		// Default to noting read.
+		last_read_ = 0xff;
+
+		while(window < 4 && window < end_window) {
+			if(should_reload_line_parameters_) {
+				switch(window) {
+					// First slot: line count, mode and interrupt flag.
+					case 0:
+						// Byte 0: lines remaining.
+						lines_remaining_ = ram_[line_parameter_pointer_];
+
+						// Byte 1: current interrupt output plus graphics modes...
+						last_read_ = ram_[line_parameter_pointer_ + 1];
+
+						// Set the new interrupt line output.
+						interrupt_line_ = ram_[line_parameter_pointer_ + 1] & 0x80;
+
+						// Determine the mode and depth, and hence the column size.
+						mode_ = Mode((ram_[line_parameter_pointer_ + 1] >> 1)&7);
+						bpp_ = 1 << ((ram_[line_parameter_pointer_ + 1] >> 5)&3);
+						switch(mode_) {
+							default:
+							case Mode::Pixel:
+								column_size_ = 16 / bpp_;
+								line_data_per_column_increments_[0] = 2;
+								line_data_per_column_increments_[1] = 0;
+							break;
+
+							case Mode::LPixel:
+							case Mode::CH64:
+							case Mode::CH128:
+							case Mode::CH256:
+								column_size_ = 8 / bpp_;
+								line_data_per_column_increments_[0] = 1;
+								line_data_per_column_increments_[1] = 0;
+							break;
+
+							case Mode::Attr:
+								column_size_ = 8;
+								line_data_per_column_increments_[0] = 1;
+								line_data_per_column_increments_[1] = 1;
+							break;
+						}
+
+						vres_ = ram_[line_parameter_pointer_ + 1] & 0x10;
+						reload_line_parameter_pointer_ = ram_[line_parameter_pointer_ + 1] & 0x01;
+					break;
+
+					// Second slot: margins and ALT/IND bits.
+					case 1:
+						// Determine the margins.
+						left_margin_ = ram_[line_parameter_pointer_ + 2] & 0x3f;
+						right_margin_ = ram_[line_parameter_pointer_ + 3] & 0x3f;
+						last_read_ = ram_[line_parameter_pointer_ + 3];
+
+						// Set up the alternative palettes,
+						switch(mode_) {
+							default:
+							break;
+
+							// NB: LSBALT/MSBALT and ALTIND0/ALTIND1 appear to have opposite effects on palette selection.
+
+							case Mode::Pixel:
+							case Mode::LPixel: {
+								const uint8_t flags = ram_[line_parameter_pointer_ + 2];
+
+								// Use MSBALT and LSBALT to pick the alt_ind_palettes.
+								//
+								// LSBALT = b6 of params[2], if set => character codes with bit 6 set should use palette indices 4... instead of 0... .
+								// MSBALT = b7 of params[2], if set => character codes with bit 7 set should use palette indices 2 and 3.
+								two_colour_mask_ = 0xff &~ (((flags&0x80) >> 7) | ((flags&0x40) << 1));
+
+								alt_ind_palettes[0] = palette_;
+								alt_ind_palettes[2] = alt_ind_palettes[0] + ((flags & 0x80) ? 2 : 0);
+
+								alt_ind_palettes[1] = alt_ind_palettes[0] + ((flags & 0x40) ? 4 : 0);
+								alt_ind_palettes[3] = alt_ind_palettes[2] + ((flags & 0x40) ? 4 : 0);
+							} break;
+
+							case Mode::CH64:
+							case Mode::CH128:
+							case Mode::CH256: {
+								const uint8_t flags = ram_[line_parameter_pointer_ + 3];
+
+								// Use ALTIND0 and ALTIND1 to pick the alt_ind_palettes.
+								//
+								// ALTIND1 = b6 of params[3], if set => character codes with bit 7 set should use palette indices 2 and 3.
+								// ALTIND0 = b7 of params[3], if set => character codes with bit 6 set should use palette indices 4... instead of 0... .
+								alt_ind_palettes[0] = palette_;
+								alt_ind_palettes[2] = alt_ind_palettes[0] + ((flags & 0x40) ? 2 : 0);
+
+								alt_ind_palettes[1] = alt_ind_palettes[0] + ((flags & 0x80) ? 4 : 0);
+								alt_ind_palettes[3] = alt_ind_palettes[2] + ((flags & 0x80) ? 4 : 0);
+							} break;
+						}
+					break;
+
+					// Third slot: Line data pointer 1.
+					case 2:
+						start_line_data_pointer_[0] = ram_[line_parameter_pointer_ + 4];
+						start_line_data_pointer_[0] |= ram_[line_parameter_pointer_ + 5] << 8;
+
+						line_data_pointer_[0] = start_line_data_pointer_[0];
+						last_read_ = ram_[line_parameter_pointer_ + 5];
+					break;
+
+					// Fourth slot: Line data pointer 2.
+					case 3:
+						start_line_data_pointer_[1] = ram_[line_parameter_pointer_ + 6];
+						start_line_data_pointer_[1] |= ram_[line_parameter_pointer_ + 7] << 8;
+
+						line_data_pointer_[1] = start_line_data_pointer_[1];
+						last_read_ = ram_[line_parameter_pointer_ + 7];
+					break;
+				}
+			}
+
+			++output_duration_;
+			add_window(1);
+		}
+		if(window == 4) {
+			if(mode_ == Mode::Vsync) {
+				set_output_type(is_sync_or_pixels_ ? OutputType::Sync : OutputType::Blank);
+			} else {
+				set_output_type(OutputType::Blank);
+			}
+		}
+
+		// Deal with vsync mode out here.
+		if(mode_ == Mode::Vsync) {
+			if(window >= 4) {
+				while(window < end_window) {
+					// Skip straight to the next event.
+					int next_event = end_window;
+					if(window < left_margin_) next_event = std::min(next_event, left_margin_);
+					if(window < right_margin_) next_event = std::min(next_event, right_margin_);
+
+					output_duration_ += next_event - window;
+					add_window(next_event - window);
+					set_output_type(is_sync_or_pixels_ ? OutputType::Sync : OutputType::Blank);
+				}
+			}
+		} else {
+			// If present then the colour burst is output for the period from
+			// the start of window 6 to the end of window 10.
+			//
+			// The first 8 palette entries also need to be fetched here.
+			while(window < first_pixel_window_ && window < end_window) {
+				if(window == 6) {
+					set_output_type(OutputType::ColourBurst);
+				}
+
+				if(should_reload_line_parameters_ && window < 8) {
+					const int base = (window - 4) << 1;
+					assert(base < 7);
+					palette_[base] = mapped_colour(ram_[line_parameter_pointer_ + base + 8]);
+					palette_[base + 1] = mapped_colour(ram_[line_parameter_pointer_ + base + 9]);
+					last_read_ = ram_[line_parameter_pointer_ + base + 9];
+				}
+
+				++output_duration_;
+				add_window(1);
+			}
+
+			if(window >= first_pixel_window_) {
+				if(window == first_pixel_window_) {
+					set_output_type(is_sync_or_pixels_ ? OutputType::Pixels : OutputType::Border);
+				}
+
+				while(window < end_window) {
+					int next_event = end_window;
+					if(window < left_margin_) next_event = std::min(next_event, left_margin_);
+					if(window < right_margin_) next_event = std::min(next_event, right_margin_);
+
+					if(is_sync_or_pixels_) {
+
+#define DispatchBpp(func) \
+	switch(bpp_) {	\
+		default:	\
+		case 1: func(1)(pixel_pointer_, output_duration);	break;	\
+		case 2: func(2)(pixel_pointer_, output_duration);	break;	\
+		case 4: func(4)(pixel_pointer_, output_duration);	break;	\
+		case 8: func(8)(pixel_pointer_, output_duration);	break;	\
+	}
+
+#define pixel(x) output_pixel<x, false>
+#define lpixel(x) output_pixel<x, true>
+#define ch256(x) output_character<x, 8>
+#define ch128(x) output_character<x, 7>
+#define ch64(x) output_character<x, 6>
+#define attr(x) output_attributed<x>
+
+						int columns_remaining = next_event - window;
+						while(columns_remaining) {
+							if(!pixel_pointer_) {
+								if(output_duration_) {
+									set_output_type(OutputType::Pixels, true);
+								}
+								pixel_pointer_ = allocated_pointer_ = reinterpret_cast<uint16_t *>(crt_.begin_data(allocation_size));
+							}
+
+							if(allocated_pointer_) {
+								const int output_duration = std::min(columns_remaining, int(allocated_pointer_ + allocation_size - pixel_pointer_) / column_size_);
+
+								switch(mode_) {
+									default:
+									case Mode::Pixel:	DispatchBpp(pixel);		break;
+									case Mode::LPixel:	DispatchBpp(lpixel);	break;
+									case Mode::CH256:	DispatchBpp(ch256);		break;
+									case Mode::CH128:	DispatchBpp(ch128);		break;
+									case Mode::CH64:	DispatchBpp(ch64);		break;
+									case Mode::Attr:	DispatchBpp(attr);		break;
+								}
+
+								pixel_pointer_ += output_duration * column_size_;
+								output_duration_ += output_duration;
+								if(pixel_pointer_ - allocated_pointer_ == allocation_size) {
+									set_output_type(OutputType::Pixels, true);
+								}
+								columns_remaining -= output_duration;
+								add_window(output_duration);
+							} else {
+								output_duration_ += columns_remaining;
+								add_window(columns_remaining);
+								columns_remaining = 0;
+							}
+						}
+
+#undef attr
+#undef ch64
+#undef ch128
+#undef ch256
+#undef pixel
+#undef lpixel
+#undef DispatchBpp
+					} else {
+						output_duration_ += next_event - window;
+						add_window(next_event - window);
+					}
+
+					set_output_type(is_sync_or_pixels_ ? OutputType::Pixels : OutputType::Border);
+				}
+			}
+		}
+
+		// Check for end of line.
+		if(!horizontal_counter_) {
+			assert(window == 57);
+
+			++lines_remaining_;
+			if(!lines_remaining_) {
+				should_reload_line_parameters_ = true;
+
+				// Check for end-of-frame.
+				if(reload_line_parameter_pointer_) {
+					line_parameter_pointer_ = line_parameter_base_;
+				} else {
+					line_parameter_pointer_ += 16;
+				}
+			} else {
+				should_reload_line_parameters_ = false;
+			}
+
+			// Deal with VRES and other address reloading, dependant upon mode.
+			switch(mode_) {
+				default: break;
+				case Mode::CH64:
+				case Mode::CH128:
+				case Mode::CH256:
+					line_data_pointer_[0] = start_line_data_pointer_[0];
+					++line_data_pointer_[1];
+				break;
+
+				case Mode::Pixel:
+				case Mode::LPixel:
+				case Mode::Attr:
+					// Reload the pixel or attribute address if VRES is clear.
+					if(!vres_) {
+						line_data_pointer_[0] = start_line_data_pointer_[0];
+					}
+				break;
+			}
+		}
+	}
+
+#undef add_window
+
+}
+
+void Nick::set_output_type(OutputType type, bool force_flush) {
+	if(type == output_type_ && !force_flush) {
+		return;
+	}
+	if(output_duration_) {
+		switch(output_type_) {
+			case OutputType::Border: {
+				uint16_t *const colour_pointer = reinterpret_cast<uint16_t *>(crt_.begin_data(1));
+				if(colour_pointer) *colour_pointer = border_colour_;
+				crt_.output_level(output_duration_*16);
+			} break;
+
+			case OutputType::Pixels: {
+				crt_.output_data(output_duration_*16, size_t(output_duration_*column_size_));
+				pixel_pointer_ = nullptr;
+				allocated_pointer_ = nullptr;
+			} break;
+
+			case OutputType::Sync:			crt_.output_sync(output_duration_*16);				break;
+			case OutputType::Blank:			crt_.output_blank(output_duration_*16);				break;
+			case OutputType::ColourBurst:	crt_.output_colour_burst(output_duration_*16, 0);	break;
+		}
+	}
+
+	output_duration_ = 0;
+	output_type_ = type;
+}
+
+// MARK: - Sequence points.
+
+Cycles Nick::get_next_sequence_point() const {
+	constexpr int load_point = 16;	// i.e. 16 cycles after the start of the line, the
+									// interrupt line may change. That is, after the
+									// second byte of the mode line has been read.
+
+	// Any mode line may cause a change in the interrupt output, so as a first blush
+	// just always report the time until the end of the mode line.
+	if(lines_remaining_ || horizontal_counter_ >= load_point) {
+		return Cycles(load_point + (912 - horizontal_counter_) + (0xff - lines_remaining_) * 912);
+	} else {
+		return Cycles(load_point - horizontal_counter_);
+	}
+}
+
+// MARK: - CRT passthroughs.
+
+void Nick::set_scan_target(Outputs::Display::ScanTarget *scan_target) {
+	crt_.set_scan_target(scan_target);
+}
+
+Outputs::Display::ScanStatus Nick::get_scaled_scan_status() const {
+	return crt_.get_scaled_scan_status();
+}
+
+void Nick::set_display_type(Outputs::Display::DisplayType display_type) {
+	first_pixel_window_ = display_type == Outputs::Display::DisplayType::RGB ? 8 : 10;
+	crt_.set_display_type(display_type);
+}
+
+Outputs::Display::DisplayType Nick::get_display_type() const {
+	return crt_.get_display_type();
+}
+
+// MARK: - Specific pixel outputters.
+
+#define output1bpp(x)	\
+	target[0] = palette[(x & 0x80) >> 7];	\
+	target[1] = palette[(x & 0x40) >> 6];	\
+	target[2] = palette[(x & 0x20) >> 5];	\
+	target[3] = palette[(x & 0x10) >> 4];	\
+	target[4] = palette[(x & 0x08) >> 3];	\
+	target[5] = palette[(x & 0x04) >> 2];	\
+	target[6] = palette[(x & 0x02) >> 1];	\
+	target[7] = palette[(x & 0x01) >> 0];	\
+	target += 8
+
+#define output2bpp(x)	\
+	target[0] = palette_[((x & 0x80) >> 7) | ((x & 0x08) >> 2)];	\
+	target[1] = palette_[((x & 0x40) >> 6) | ((x & 0x04) >> 1)];	\
+	target[2] = palette_[((x & 0x20) >> 5) | ((x & 0x02) >> 0)];	\
+	target[3] = palette_[((x & 0x10) >> 4) | ((x & 0x01) << 1)];	\
+	target += 4
+
+#define output4bpp(x)	\
+	target[0] = palette_[((x & 0x02) << 2) | ((x & 0x20) >> 3) | ((x & 0x08) >> 2) | ((x & 0x80) >> 7)];	\
+	target[1] = palette_[((x & 0x01) << 3) | ((x & 0x10) >> 2) | ((x & 0x04) >> 1) | ((x & 0x40) >> 6)];	\
+	target += 2
+
+#define output8bpp(x)	\
+	target[0] = mapped_colour(x);	\
+	++target
+
+template <int bpp, bool is_lpixel> void Nick::output_pixel(uint16_t *target, int columns) const {
+	static_assert(bpp == 1 || bpp == 2 || bpp == 4 || bpp == 8);
+
+	int index = 0;
+	for(int c = 0; c < columns; c++) {
+		uint8_t pixels[2] = {
+			ram_[(line_data_pointer_[0] + index) & 0xffff],
+			ram_[(line_data_pointer_[0] + index + 1) & 0xffff]
+		};
+		index += is_lpixel ? 1 : 2;
+		last_read_ = pixels[1];
+
+		switch(bpp) {
+			default:
+			case 1: {
+				const uint16_t *palette = alt_ind_palettes[((pixels[0] >> 6) & 0x02) | (pixels[0]&1)];
+				pixels[0] &= two_colour_mask_;
+				output1bpp(pixels[0]);
+
+				if constexpr (!is_lpixel) {
+					palette = alt_ind_palettes[((pixels[1] >> 6) & 0x02) | (pixels[1]&1)];
+					pixels[1] &= two_colour_mask_;
+					output1bpp(pixels[1]);
+				}
+			} break;
+
+			case 2:
+				output2bpp(pixels[0]);
+				if constexpr (!is_lpixel) {
+					output2bpp(pixels[1]);
+				}
+			break;
+
+			case 4:
+				output4bpp(pixels[0]);
+				if constexpr (!is_lpixel) {
+					output4bpp(pixels[1]);
+				}
+			break;
+
+			case 8:
+				output8bpp(pixels[0]);
+				if constexpr (!is_lpixel) {
+					output8bpp(pixels[1]);
+				}
+			break;
+		}
+	}
+}
+
+template <int bpp, int index_bits> void Nick::output_character(uint16_t *target, int columns) const {
+	static_assert(bpp == 1 || bpp == 2 || bpp == 4 || bpp == 8);
+
+	for(int c = 0; c < columns; c++) {
+		const uint8_t character = ram_[(line_data_pointer_[0] + c) & 0xffff];
+		const uint8_t pixels = ram_[(
+			(line_data_pointer_[1] << index_bits) +
+			(character & ((1 << index_bits) - 1))
+		) & 0xffff];
+		last_read_ = pixels;
+
+		switch(bpp) {
+			default:
+				assert(false);
+			break;
+
+			case 1: {
+				// This applies ALTIND0 and ALTIND1.
+				const uint16_t *palette = alt_ind_palettes[character >> 6];
+				output1bpp(pixels);
+			} break;
+
+			case 2:		output2bpp(pixels);		break;
+			case 4:		output4bpp(pixels);		break;
+			case 8:		output8bpp(pixels);		break;
+		}
+	}
+}
+
+template <int bpp> void Nick::output_attributed(uint16_t *target, int columns) const {
+	static_assert(bpp == 1 || bpp == 2 || bpp == 4 || bpp == 8);
+
+	for(int c = 0; c < columns; c++) {
+		const uint8_t pixels = ram_[(line_data_pointer_[1] + c) & 0xffff];
+		const uint8_t attributes = ram_[(line_data_pointer_[0] + c) & 0xffff];
+		last_read_ = pixels;
+
+		const uint16_t palette[2] = {
+			palette_[attributes >> 4], palette_[attributes & 0x0f]
+		};
+		output1bpp(pixels);
+	}
+}
+
+#undef output1bpp
+#undef output2bpp
+#undef output4bpp
+#undef output8bpp

Machines/Enterprise/Nick.hpp

@@ -0,0 +1,129 @@
+//
+//  Nick.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 14/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#ifndef Nick_hpp
+#define Nick_hpp
+
+#include <cstdint>
+#include "../../ClockReceiver/ClockReceiver.hpp"
+#include "../../Outputs/CRT/CRT.hpp"
+
+namespace Enterprise {
+
+class Nick {
+	public:
+		Nick(const uint8_t *ram);
+
+		/// Writes to a Nick register; only the low two bits are decoded.
+		void write(uint16_t address, uint8_t value);
+
+		/// Reads from the Nick range. Nobody seems to be completely clear what
+		/// this should return; I've set it up to return the last fetched video or mode
+		/// line byte during periods when those things are being fetched, 0xff at all
+		/// other times. Including during refresh, since I don't know what addresses
+		/// are generated then.
+		///
+		/// This likely isn't accurate, but is the most accurate guess I could make.
+		uint8_t read();
+
+		void run_for(Cycles);
+		Cycles get_time_until_z80_slot(Cycles after_period) const;
+
+		void set_scan_target(Outputs::Display::ScanTarget *scan_target);
+		Outputs::Display::ScanStatus get_scaled_scan_status() const;
+
+		/// @returns The amount of time until the next potential change in interrupt output.
+		Cycles get_next_sequence_point() const;
+
+		/*!
+			@returns The current state of the interrupt line — @c true for active;
+				@c false for inactive.
+		*/
+		inline bool get_interrupt_line() const {
+			return interrupt_line_;
+		}
+
+		/// Sets the type of output.
+		void set_display_type(Outputs::Display::DisplayType);
+
+		/// Gets the type of output.
+		Outputs::Display::DisplayType get_display_type() const;
+
+	private:
+		Outputs::CRT::CRT crt_;
+		const uint8_t *const ram_;
+
+		// CPU-provided state.
+		uint8_t line_parameter_control_ = 0xc0;
+		uint16_t line_parameter_base_ = 0x0000;
+		uint16_t border_colour_ = 0;
+
+		// Ephemerals, related to current video position.
+		int horizontal_counter_ = 0;
+		uint16_t line_parameter_pointer_ = 0x0000;
+		bool should_reload_line_parameters_ = true;
+		uint16_t line_data_pointer_[2];
+		uint16_t start_line_data_pointer_[2];
+		mutable uint8_t last_read_ = 0xff;
+
+		// Current mode line parameters.
+		uint8_t lines_remaining_ = 0x00;
+		uint8_t two_colour_mask_ = 0xff;
+		int left_margin_ = 0, right_margin_ = 0;
+		const uint16_t *alt_ind_palettes[4];
+		enum class Mode {
+			Vsync,
+			Pixel,
+			Attr,
+			CH256,
+			CH128,
+			CH64,
+			Unused,
+			LPixel,
+		} mode_ = Mode::Vsync;
+		bool is_sync_or_pixels_ = false;
+		int bpp_ = 0;
+		int column_size_ = 0;
+		bool interrupt_line_ = true;
+		int line_data_per_column_increments_[2] = {0, 0};
+		bool vres_ = false;
+		bool reload_line_parameter_pointer_ = false;
+
+		// An accumulator for border output regions.
+		int border_duration_ = 0;
+
+		// The destination for new pixels.
+		static constexpr int allocation_size = 336;
+		static_assert((allocation_size % 16) == 0, "Allocation size must be a multiple of 16");
+		uint16_t *pixel_pointer_ = nullptr, *allocated_pointer_ = nullptr;
+
+		// Output transitions.
+		enum class OutputType {
+			Sync, Blank, Pixels, Border, ColourBurst
+		};
+		void set_output_type(OutputType, bool force_flush = false);
+		int output_duration_ = 0;
+		OutputType output_type_ = OutputType::Sync;
+
+		// Current palette.
+		uint16_t palette_[16]{};
+
+		// The first column with pixels on it; will be either 8 or 10 depending
+		// on whether the colour burst is meaningful to the current display type.
+		int first_pixel_window_ = 10;
+
+		// Specific outputters.
+		template <int bpp, bool is_lpixel> void output_pixel(uint16_t *target, int columns) const;
+		template <int bpp, int index_bits> void output_character(uint16_t *target, int columns) const;
+		template <int bpp> void output_attributed(uint16_t *target, int columns) const;
+};
+
+
+}
+
+#endif /* Nick_hpp */

Machines/MSX/MSX.cpp

@@ -169,19 +169,22 @@ class ConcreteMachine:
 
 			// Install the proper TV standard and select an ideal BIOS name.
 			const std::string machine_name = "MSX";
-			std::vector<ROMMachine::ROM> required_roms = {
-				{machine_name, "any MSX BIOS", "msx.rom", 32*1024, 0x94ee12f3}
-			};
+			ROM::Request bios_request = ROM::Request(ROM::Name::MSXGenericBIOS);
+//			std::vector<ROMMachine::ROM> required_roms = {
+//				{machine_name, "any MSX BIOS", "msx.rom", 32*1024, 0x94ee12f3u}
+//			};
 
 			bool is_ntsc = true;
 			uint8_t character_generator = 1;	/* 0 = Japan, 1 = USA, etc, 2 = USSR */
 			uint8_t date_format = 1;			/* 0 = Y/M/D, 1 = M/D/Y, 2 = D/M/Y */
 			uint8_t keyboard = 1;				/* 0 = Japan, 1 = USA, 2 = France, 3 = UK, 4 = Germany, 5 = USSR, 6 = Spain */
+			ROM::Name regional_bios_name;
 
 			// TODO: CRCs below are incomplete, at best.
 			switch(target.region) {
+				default:
 				case Target::Region::Japan:
-					required_roms.emplace_back(machine_name, "a Japanese MSX BIOS", "msx-japanese.rom", 32*1024, 0xee229390);
+					regional_bios_name = ROM::Name::MSXJapaneseBIOS;
 					vdp_->set_tv_standard(TI::TMS::TVStandard::NTSC);
 
 					is_ntsc = true;
@@ -189,7 +192,7 @@ class ConcreteMachine:
 					date_format = 0;
 				break;
 				case Target::Region::USA:
-					required_roms.emplace_back(machine_name, "an American MSX BIOS", "msx-american.rom", 32*1024, 0);
+					regional_bios_name = ROM::Name::MSXAmericanBIOS;
 					vdp_->set_tv_standard(TI::TMS::TVStandard::NTSC);
 
 					is_ntsc = true;
@@ -197,7 +200,7 @@ class ConcreteMachine:
 					date_format = 1;
 				break;
 				case Target::Region::Europe:
-					required_roms.emplace_back(machine_name, "a European MSX BIOS", "msx-european.rom", 32*1024, 0);
+					regional_bios_name = ROM::Name::MSXEuropeanBIOS;
 					vdp_->set_tv_standard(TI::TMS::TVStandard::PAL);
 
 					is_ntsc = false;
@@ -205,27 +208,30 @@ class ConcreteMachine:
 					date_format = 2;
 				break;
 			}
+			bios_request = bios_request || ROM::Request(regional_bios_name);
 
 			// Fetch the necessary ROMs; try the region-specific ROM first,
 			// but failing that fall back on patching the main one.
-			size_t disk_index = 0;
+			ROM::Request request;
 			if(target.has_disk_drive) {
-				disk_index = required_roms.size();
-				required_roms.emplace_back(machine_name, "the MSX-DOS ROM", "disk.rom", 16*1024, 0x721f61df);
+				request = ROM::Request(ROM::Name::MSXDOS) && bios_request;
+			} else {
+				request = bios_request;
 			}
-			const auto roms = rom_fetcher(required_roms);
 
-			if((!roms[0] && !roms[1]) || (target.has_disk_drive && !roms[2])) {
+			auto roms = rom_fetcher(request);
+			if(!request.validate(roms)) {
 				throw ROMMachine::Error::MissingROMs;
 			}
 
 			// Figure out which BIOS to use, either a specific one or the generic
 			// one appropriately patched.
-			if(roms[1]) {
-				memory_slots_[0].source = std::move(*roms[1]);
+			const auto regional_bios = roms.find(regional_bios_name);
+			if(regional_bios != roms.end()) {
+				memory_slots_[0].source = std::move(regional_bios->second);
 				memory_slots_[0].source.resize(32768);
 			} else {
-				memory_slots_[0].source = std::move(*roms[0]);
+				memory_slots_[0].source = std::move(roms.find(ROM::Name::MSXGenericBIOS)->second);
 				memory_slots_[0].source.resize(32768);
 
 				memory_slots_[0].source[0x2b] = uint8_t(
@@ -252,7 +258,7 @@ class ConcreteMachine:
 			// Add a disk cartridge if any disks were supplied.
 			if(target.has_disk_drive) {
 				memory_slots_[2].set_handler(new DiskROM(memory_slots_[2].source));
-				memory_slots_[2].source = std::move(*roms[disk_index]);
+				memory_slots_[2].source = std::move(roms.find(ROM::Name::MSXDOS)->second);
 				memory_slots_[2].source.resize(16384);
 
 				map(2, 0, 0x4000, 0x2000);

Machines/MachineTypes.hpp

@@ -20,6 +20,7 @@
 #include "MediaTarget.hpp"
 #include "MouseMachine.hpp"
 #include "ScanProducer.hpp"
+#include "StateProducer.hpp"
 #include "TimedMachine.hpp"
 
 #endif /* MachineTypes_h */

Machines/MasterSystem/MasterSystem.cpp

@@ -141,23 +141,20 @@ class ConcreteMachine:
 			//	0072ed54 = US/European BIOS 1.3
 			//	48d44a13 = Japanese BIOS 2.1
 			const bool is_japanese = target.region == Target::Region::Japan;
-			const auto roms = rom_fetcher(
-				{ {"MasterSystem",
-					is_japanese ? "the Japanese Master System BIOS" : "the European/US Master System BIOS",
-					is_japanese ? "japanese-bios.sms" : "bios.sms",
-					8*1024,
-					{ is_japanese ? 0x48d44a13u : 0x0072ed54u }
-				} }
-			);
-			if(!roms[0]) {
+			const ROM::Name bios_name = is_japanese ? ROM::Name::MasterSystemJapaneseBIOS : ROM::Name::MasterSystemWesternBIOS;
+			ROM::Request request(bios_name, true);
+			auto roms = rom_fetcher(request);
+			request.validate(roms);
+
+			const auto rom = roms.find(bios_name);
+			if(rom == roms.end()) {
 				// No BIOS found; attempt to boot as though it has already disabled itself.
 				has_bios_ = false;
 				memory_control_ |= 0x08;
 				std::cerr << "No BIOS found; attempting to start cartridge directly" << std::endl;
 			} else {
 				has_bios_ = true;
-				roms[0]->resize(8*1024);
-				memcpy(&bios_, roms[0]->data(), roms[0]->size());
+				memcpy(&bios_, rom->second.data(), std::min(sizeof(bios_), rom->second.size()));
 			}
 			page_cartridge();
 

Machines/Oric/Keyboard.cpp

@@ -127,5 +127,5 @@ const uint16_t *CharacterMapper::sequence_for_character(char character) const {
 #undef SHIFT
 #undef X
 
-	return table_lookup_sequence_for_character(key_sequences, sizeof(key_sequences), character);
+	return table_lookup_sequence_for_character(key_sequences, character);
 }

Machines/Oric/Oric.cpp

@@ -40,6 +40,45 @@
 #include <memory>
 #include <vector>
 
+namespace {
+
+/*!
+	Provides an Altai-style joystick.
+*/
+class Joystick: public Inputs::ConcreteJoystick {
+	public:
+		Joystick() :
+			ConcreteJoystick({
+				Input(Input::Up),
+				Input(Input::Down),
+				Input(Input::Left),
+				Input(Input::Right),
+				Input(Input::Fire)
+			}) {}
+
+		void did_set_input(const Input &digital_input, bool is_active) final {
+#define APPLY(b)	if(is_active) state_ &= ~b; else state_ |= b;
+			switch(digital_input.type) {
+				default: return;
+				case Input::Right:	APPLY(0x02);	break;
+				case Input::Left:	APPLY(0x01);	break;
+				case Input::Down:	APPLY(0x08);	break;
+				case Input::Up:		APPLY(0x10);	break;
+				case Input::Fire:	APPLY(0x20);	break;
+			}
+#undef APPLY
+		}
+
+		uint8_t get_state() {
+			return state_;
+		}
+
+	private:
+		uint8_t state_ = 0xff;
+};
+
+}
+
 namespace Oric {
 
 using DiskInterface = Analyser::Static::Oric::Target::DiskInterface;
@@ -140,7 +179,12 @@ class TapePlayer: public Storage::Tape::BinaryTapePlayer {
 class VIAPortHandler: public MOS::MOS6522::IRQDelegatePortHandler {
 	public:
 		VIAPortHandler(Concurrency::DeferringAsyncTaskQueue &audio_queue, AY &ay8910, Speaker &speaker, TapePlayer &tape_player, Keyboard &keyboard) :
-			audio_queue_(audio_queue), ay8910_(ay8910), speaker_(speaker), tape_player_(tape_player), keyboard_(keyboard) {}
+			audio_queue_(audio_queue), ay8910_(ay8910), speaker_(speaker), tape_player_(tape_player), keyboard_(keyboard)
+		{
+			// Attach a couple of joysticks.
+			joysticks_.emplace_back(new Joystick);
+			joysticks_.emplace_back(new Joystick);
+		}
 
 		/*!
 			Reponds to the 6522's control line output change signal; on an Oric A2 is connected to
@@ -165,6 +209,7 @@ class VIAPortHandler: public MOS::MOS6522::IRQDelegatePortHandler {
 			} else {
 				update_ay();
 				ay8910_.set_data_input(value);
+				porta_output_ = value;
 			}
 		}
 
@@ -176,7 +221,10 @@ class VIAPortHandler: public MOS::MOS6522::IRQDelegatePortHandler {
 				uint8_t column = ay8910_.get_port_output(false) ^ 0xff;
 				return keyboard_.query_column(column) ? 0x08 : 0x00;
 			} else {
-				return ay8910_.get_data_output();
+				uint8_t result = ay8910_.get_data_output();
+				if(porta_output_ & 0x40) result &= static_cast<Joystick *>(joysticks_[0].get())->get_state();
+				if(porta_output_ & 0x80) result &= static_cast<Joystick *>(joysticks_[1].get())->get_state();
+				return result;
 			}
 		}
 
@@ -193,12 +241,17 @@ class VIAPortHandler: public MOS::MOS6522::IRQDelegatePortHandler {
 			audio_queue_.perform();
 		}
 
+		const std::vector<std::unique_ptr<Inputs::Joystick>> &get_joysticks() {
+			return joysticks_;
+		}
+
 	private:
 		void update_ay() {
 			speaker_.run_for(audio_queue_, cycles_since_ay_update_.flush<Cycles>());
 		}
 		bool ay_bdir_ = false;
 		bool ay_bc1_ = false;
+		uint8_t porta_output_ = 0xff;
 		HalfCycles cycles_since_ay_update_;
 
 		Concurrency::DeferringAsyncTaskQueue &audio_queue_;
@@ -206,12 +259,15 @@ class VIAPortHandler: public MOS::MOS6522::IRQDelegatePortHandler {
 		Speaker &speaker_;
 		TapePlayer &tape_player_;
 		Keyboard &keyboard_;
+
+		std::vector<std::unique_ptr<Inputs::Joystick>> joysticks_;
 };
 
 template <Analyser::Static::Oric::Target::DiskInterface disk_interface, CPU::MOS6502Esque::Type processor_type> class ConcreteMachine:
 	public MachineTypes::TimedMachine,
 	public MachineTypes::ScanProducer,
 	public MachineTypes::AudioProducer,
+	public MachineTypes::JoystickMachine,
 	public MachineTypes::MediaTarget,
 	public MachineTypes::MappedKeyboardMachine,
 	public Configurable::Device,
@@ -248,73 +304,64 @@ template <Analyser::Static::Oric::Target::DiskInterface disk_interface, CPU::MOS
 				ram_[c] |= 0x40;
 			}
 
-			const std::string machine_name = "Oric";
-			std::vector<ROMMachine::ROM> rom_names = { {machine_name, "the Oric colour ROM", "colour.rom", 128, 0xd50fca65} };
+			::ROM::Request request = ::ROM::Request(::ROM::Name::OricColourROM, true);
+			::ROM::Name basic;
 			switch(target.rom) {
-				case Analyser::Static::Oric::Target::ROM::BASIC10:
-					rom_names.emplace_back(machine_name, "Oric BASIC 1.0", "basic10.rom", 16*1024, 0xf18710b4);
-				break;
-				case Analyser::Static::Oric::Target::ROM::BASIC11:
-					rom_names.emplace_back(machine_name, "Oric BASIC 1.1", "basic11.rom", 16*1024, 0xc3a92bef);
-				break;
-				case Analyser::Static::Oric::Target::ROM::Pravetz:
-					rom_names.emplace_back(machine_name, "Pravetz BASIC", "pravetz.rom", 16*1024, 0x58079502);
-				break;
+				case Analyser::Static::Oric::Target::ROM::BASIC10:	basic = ::ROM::Name::OricBASIC10;		break;
+				default:
+				case Analyser::Static::Oric::Target::ROM::BASIC11:	basic = ::ROM::Name::OricBASIC11;		break;
+				case Analyser::Static::Oric::Target::ROM::Pravetz:	basic = ::ROM::Name::OricPravetzBASIC;	break;
 			}
-			size_t diskii_state_machine_index = 0;
+			request = request && ::ROM::Request(basic);
+
 			switch(disk_interface) {
 				default: break;
 				case DiskInterface::BD500:
-					rom_names.emplace_back(machine_name, "the Oric Byte Drive 500 ROM", "bd500.rom", 8*1024, 0x61952e34);
+					request = request && ::ROM::Request(::ROM::Name::OricByteDrive500);
 				break;
 				case DiskInterface::Jasmin:
-					rom_names.emplace_back(machine_name, "the Oric Jasmin ROM", "jasmin.rom", 2*1024, 0x37220e89);
+					request = request && ::ROM::Request(::ROM::Name::OricJasmin);
 				break;
 				case DiskInterface::Microdisc:
-					rom_names.emplace_back(machine_name, "the Oric Microdisc ROM", "microdisc.rom", 8*1024, 0xa9664a9c);
+					request = request && ::ROM::Request(::ROM::Name::OricMicrodisc);
 				break;
 				case DiskInterface::Pravetz:
-					rom_names.emplace_back(machine_name, "the 8DOS boot ROM", "8dos.rom", 512, 0x49a74c06);
-					// These ROM details are coupled with those in the DiskIICard.
-					diskii_state_machine_index = rom_names.size();
-					rom_names.push_back({"DiskII", "the Disk II 16-sector state machine ROM", "state-machine-16.rom", 256, { 0x9796a238, 0xb72a2c70 }});
+					request = request && ::ROM::Request(::ROM::Name::Oric8DOSBoot) && ::ROM::Request(::ROM::Name::DiskIIStateMachine16Sector);
 				break;
 			}
 
-			const auto roms = rom_fetcher(rom_names);
-
-			for(std::size_t index = 0; index < roms.size(); ++index) {
-				if(!roms[index]) {
-					throw ROMMachine::Error::MissingROMs;
-				}
+			auto roms = rom_fetcher(request);
+			if(!request.validate(roms)) {
+				throw ROMMachine::Error::MissingROMs;
 			}
 
-			video_->set_colour_rom(*roms[0]);
-			rom_ = std::move(*roms[1]);
+			// The colour ROM is optional; an alternative composite encoding can be used if
+			// it is absent.
+			const auto colour_rom = roms.find(::ROM::Name::OricColourROM);
+			if(colour_rom != roms.end()) {
+				video_->set_colour_rom(colour_rom->second);
+			}
+			rom_ = std::move(roms.find(basic)->second);
 
 			switch(disk_interface) {
 				default: break;
 				case DiskInterface::BD500:
-					disk_rom_ = std::move(*roms[2]);
-					disk_rom_.resize(8192);
+					disk_rom_ = std::move(roms.find(::ROM::Name::OricByteDrive500)->second);
 				break;
 				case DiskInterface::Jasmin:
-					disk_rom_ = std::move(*roms[2]);
-					disk_rom_.resize(2048);
+					disk_rom_ = std::move(roms.find(::ROM::Name::OricJasmin)->second);
 				break;
 				case DiskInterface::Microdisc:
-					disk_rom_ = std::move(*roms[2]);
-					disk_rom_.resize(8192);
+					disk_rom_ = std::move(roms.find(::ROM::Name::OricMicrodisc)->second);
 				break;
 				case DiskInterface::Pravetz: {
-					pravetz_rom_ = std::move(*roms[2]);
+					pravetz_rom_ = std::move(roms.find(::ROM::Name::Oric8DOSBoot)->second);
 					pravetz_rom_.resize(512);
 
-					diskii_->set_state_machine(*roms[diskii_state_machine_index]);
+					diskii_->set_state_machine(roms.find(::ROM::Name::DiskIIStateMachine16Sector)->second);
 				} break;
 			}
 
-			rom_.resize(16384);
 			paged_rom_ = rom_.data();
 
 			switch(target.disk_interface) {
@@ -731,8 +778,13 @@ template <Analyser::Static::Oric::Target::DiskInterface disk_interface, CPU::MOS
 			}
 		}
 
-		// MARK - typing
+		// MARK: - typing
 		std::unique_ptr<Utility::StringSerialiser> string_serialiser_;
+
+		// MARK: - Joysticks
+		const std::vector<std::unique_ptr<Inputs::Joystick>> &get_joysticks() override {
+			return via_port_handler_.get_joysticks();
+		}
 };
 
 }

Machines/Oric/Video.cpp

@@ -54,7 +54,7 @@ void VideoOutput::set_display_type(Outputs::Display::DisplayType display_type) {
 
 #ifdef SUPPLY_COMPOSITE
 	const auto data_type =
-		(display_type == Outputs::Display::DisplayType::RGB) ?
+		(!has_colour_rom_ || display_type == Outputs::Display::DisplayType::RGB) ?
 			Outputs::Display::InputDataType::Red1Green1Blue1 :
 			Outputs::Display::InputDataType::PhaseLinkedLuminance8;
 #else
@@ -80,6 +80,7 @@ Outputs::Display::ScanStatus VideoOutput::get_scaled_scan_status() const {
 }
 
 void VideoOutput::set_colour_rom(const std::vector<uint8_t> &rom) {
+	has_colour_rom_ = true;
 	for(std::size_t c = 0; c < 8; c++) {
 		colour_forms_[c] = 0;
 

Machines/Oric/Video.hpp

@@ -37,6 +37,7 @@ class VideoOutput {
 		Outputs::CRT::CRT crt_;
 		Outputs::CRT::CRTFrequencyMismatchWarner<VideoOutput> frequency_mismatch_warner_;
 		bool crt_is_60Hz_ = false;
+		bool has_colour_rom_ = false;
 
 		void update_crt_frequency();
 

Machines/ROMMachine.hpp

@@ -10,38 +10,16 @@
 #define ROMMachine_hpp
 
 #include <functional>
+#include <map>
 #include <memory>
+#include <optional>
 #include <string>
 #include <vector>
 
+#include "Utility/ROMCatalogue.hpp"
+
 namespace ROMMachine {
 
-/*!
-	Describes a ROM image; this term is used in this emulator strictly in the sense of firmware —
-	system software that is an inherent part of a machine.
-*/
-struct ROM {
-	/// The machine with which this ROM is associated, in a form that is safe for using as
-	/// part of a file name.
-	std::string machine_name;
-	/// A descriptive name for this ROM, suitable for use in a bullet-point list, a bracket
-	/// clause, etc, e.g. "the Electron MOS 1.0".
-	std::string descriptive_name;
-	/// An idiomatic file name for this ROM, e.g. "os10.rom".
-	std::string file_name;
-	/// The expected size of this ROM in bytes, e.g. 32768.
-	size_t size = 0;
-	/// CRC32s for all known acceptable copies of this ROM; intended to allow a host platform
-	/// to test user-provided ROMs of unknown provenance. **Not** intended to be used
-	/// to exclude ROMs where the user's intent is otherwise clear.
-	std::vector<uint32_t> crc32s;
-
-	ROM(std::string machine_name, std::string descriptive_name, std::string file_name, size_t size, uint32_t crc32) :
-		machine_name(machine_name), descriptive_name(descriptive_name), file_name(file_name), size(size), crc32s({crc32}) {}
-	ROM(std::string machine_name, std::string descriptive_name, std::string file_name, size_t size, std::initializer_list<uint32_t> crc32s) :
-		machine_name(machine_name), descriptive_name(descriptive_name), file_name(file_name), size(size), crc32s(crc32s) {}
-};
-
 /*!
 	Defines the signature for a function that must be supplied by the host environment in order to give machines
 	a route for fetching any system ROMs they might need.
@@ -50,7 +28,7 @@ struct ROM {
 	return a vector of unique_ptrs that either contain the contents of the ROM from @c names that corresponds by
 	index, or else are @c nullptr.
 */
-typedef std::function<std::vector<std::unique_ptr<std::vector<uint8_t>>>(const std::vector<ROM> &roms)> ROMFetcher;
+typedef std::function<ROM::Map(const ROM::Request &request)> ROMFetcher;
 
 enum class Error {
 	MissingROMs

Machines/Sinclair/Keyboard/Keyboard.cpp

@@ -275,13 +275,14 @@ const uint16_t *CharacterMapper::sequence_for_character(char character) const {
 
 	switch(machine_) {
 		case Machine::ZX80:
-		return table_lookup_sequence_for_character(zx80_key_sequences, sizeof(zx80_key_sequences), character);
+		return table_lookup_sequence_for_character(zx80_key_sequences, character);
 
 		case Machine::ZX81:
-		return table_lookup_sequence_for_character(zx81_key_sequences, sizeof(zx81_key_sequences), character);
+		return table_lookup_sequence_for_character(zx81_key_sequences, character);
 
+		default:
 		case Machine::ZXSpectrum:
-		return table_lookup_sequence_for_character(spectrum_key_sequences, sizeof(zx81_key_sequences), character);
+		return table_lookup_sequence_for_character(spectrum_key_sequences, character);
 	}
 }
 

Machines/Sinclair/ZX8081/ZX8081.cpp

@@ -74,15 +74,13 @@ template<bool is_zx81> class ConcreteMachine:
 			speaker_.set_input_rate(float(ZX8081ClockRate) / 2.0f);
 
 			const bool use_zx81_rom = target.is_ZX81 || target.ZX80_uses_ZX81_ROM;
-			const auto roms =
-				use_zx81_rom ?
-					rom_fetcher({ {"ZX8081", "the ZX81 BASIC ROM", "zx81.rom", 8 * 1024, 0x4b1dd6eb} }) :
-					rom_fetcher({ {"ZX8081", "the ZX80 BASIC ROM", "zx80.rom", 4 * 1024, 0x4c7fc597} });
-
-			if(!roms[0]) throw ROMMachine::Error::MissingROMs;
-
-			rom_ = std::move(*roms[0]);
-			rom_.resize(use_zx81_rom ? 8192 : 4096);
+			const ROM::Name rom_name = use_zx81_rom ? ROM::Name::ZX81 : ROM::Name::ZX80;
+			const ROM::Request request(rom_name);
+			auto roms = rom_fetcher(request);
+			if(!request.validate(roms)) {
+				throw ROMMachine::Error::MissingROMs;
+			}
+			rom_ = std::move(roms.find(rom_name)->second);
 
 			rom_mask_ = uint16_t(rom_.size() - 1);
 

Machines/Sinclair/ZX8081/ZX8081.hpp

@@ -32,7 +32,7 @@ class Machine {
 		class Options: public Reflection::StructImpl<Options>, public Configurable::QuickloadOption<Options> {
 			friend Configurable::QuickloadOption<Options>;
 			public:
-				bool automatic_tape_motor_control;
+				bool automatic_tape_motor_control = true;
 
 				Options(Configurable::OptionsType type):
 					Configurable::QuickloadOption<Options>(type == Configurable::OptionsType::UserFriendly),

Machines/Sinclair/ZXSpectrum/State.hpp

@@ -0,0 +1,53 @@
+//
+//  State.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 25/04/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#ifndef State_hpp
+#define State_hpp
+
+#include "../../../Reflection/Struct.hpp"
+#include "../../../Processors/Z80/State/State.hpp"
+
+#include "Video.hpp"
+#include "../../../Components/AY38910/AY38910.hpp"
+
+namespace Sinclair {
+namespace ZXSpectrum {
+
+
+struct State: public Reflection::StructImpl<State> {
+	CPU::Z80::State z80;
+	Video::State video;
+
+	// In 16kb or 48kb mode, RAM will be 16kb or 48kb and represent
+	// memory in standard linear order. In 128kb mode, RAM will be
+	// 128kb with the first 16kb representing bank 0, the next bank 1, etc.
+	std::vector<uint8_t> ram;
+
+	// Meaningful for 128kb machines only.
+	uint8_t last_7ffd = 0;
+	GI::AY38910::State ay;
+
+	// Meaningful for the +2a and +3 only.
+	uint8_t last_1ffd = 0;
+
+	State() {
+		if(needs_declare()) {
+			DeclareField(z80);
+			DeclareField(video);
+			DeclareField(ram);
+			DeclareField(last_7ffd);
+			DeclareField(last_1ffd);
+			DeclareField(ay);
+		}
+	}
+};
+
+}
+}
+
+#endif /* State_h */

Machines/Sinclair/ZXSpectrum/Video.hpp

@@ -12,12 +12,15 @@
 #include "../../../Outputs/CRT/CRT.hpp"
 #include "../../../ClockReceiver/ClockReceiver.hpp"
 
+#include "../../../Reflection/Struct.hpp"
+
 #include <algorithm>
 
 namespace Sinclair {
 namespace ZXSpectrum {
+namespace Video {
 
-enum class VideoTiming {
+enum class Timing {
 	FortyEightK,
 	OneTwoEightK,
 	Plus3,
@@ -47,11 +50,11 @@ enum class VideoTiming {
 
 */
 
-template <VideoTiming timing> class Video {
+template <Timing timing> class Video {
 	private:
 		struct Timings {
 			// Number of cycles per line. Will be 224 or 228.
-			int cycles_per_line;
+			int half_cycles_per_line;
 			// Number of lines comprising a whole frame. Will be 311 or 312.
 			int lines_per_frame;
 
@@ -63,128 +66,56 @@ template <VideoTiming timing> class Video {
 			// Number of cycles after first pixel fetch at which interrupt is first signalled.
 			int interrupt_time;
 
-			// Contention to apply, in half-cycles, as a function of number of half cycles since
+			// Contention to apply, in whole cycles, as a function of number of whole cycles since
 			// contention began.
-			int delays[16];
+			int delays[8];
+
+			constexpr Timings(int cycles_per_line, int lines_per_frame, int contention_leadin, int contention_duration, int interrupt_offset, const int *delays) noexcept :
+				half_cycles_per_line(cycles_per_line * 2),
+				lines_per_frame(lines_per_frame),
+				contention_leadin(contention_leadin * 2),
+				contention_duration(contention_duration * 2),
+				interrupt_time((cycles_per_line * lines_per_frame - interrupt_offset - contention_leadin) * 2),
+				delays{ delays[0] * 2, delays[1] * 2, delays[2] * 2, delays[3] * 2, delays[4] * 2, delays[5] * 2, delays[6] * 2, delays[7] * 2}
+			 {}
 		};
 
 		static constexpr Timings get_timings() {
-			if constexpr (timing == VideoTiming::Plus3) {
-				// Amstrad gate array timings, classic statement:
-				//
-				// Contention begins 14361 cycles "after interrupt" and follows the pattern [1, 0, 7, 6 5 4, 3, 2].
-				// The first four bytes of video are fetched at 14365–14368 cycles, in the order [pixels, attribute, pixels, attribute].
-				//
-				// For my purposes:
-				//
-				// Video fetching always begins at 0. Since there are 311*228 = 70908 cycles per frame, and the interrupt
-				// should "occur" (I assume: begin) 14365 before that, it should actually begin at 70908 - 14365 = 56543.
-				//
-				// Contention begins four cycles before the first video fetch, so it begins at 70904. I don't currently
-				// know whether the four cycles is true across all models, so it's given here as convention_leadin.
-				//
-				// ... except that empirically that all seems to be two cycles off. So maybe I misunderstand what the
-				// contention patterns are supposed to indicate relative to MREQ? It's frustrating that all documentation
-				// I can find is vaguely in terms of contention patterns, and what they mean isn't well-defined in terms
-				// of regular Z80 signalling.
-				constexpr Timings result = {
-					.cycles_per_line = 228 * 2,
-					.lines_per_frame = 311,
-
-					// i.e. video fetching begins five cycles after the start of the
-					// contended memory pattern below; that should put a clear two
-					// cycles between a Z80 access and the first video fetch.
-					.contention_leadin = 5 * 2,
-					.contention_duration = 129 * 2,
-
-					// i.e. interrupt is first signalled 14368 cycles before the first video fetch.
-					.interrupt_time = (228*311 - 14360) * 2,
-
-					.delays = {		// Should start at 14365
-						2, 1,
-						0, 0,
-						14, 13,
-						12, 11,
-						10, 9,
-						8, 7,
-						6, 5,
-						4, 3,
-					}
-				};
-
-				return result;
+			if constexpr (timing == Timing::Plus3) {
+				constexpr int delays[] = {1, 0, 7, 6, 5, 4, 3, 2};
+				return Timings(228, 311, 6, 129, 14361, delays);
 			}
 
-			if constexpr (timing == VideoTiming::OneTwoEightK) {
-				constexpr Timings result = {
-					.cycles_per_line = 228 * 2,
-					.lines_per_frame = 311,
-
-					.contention_leadin = 4 * 2,
-					.contention_duration = 128 * 2,
-
-					.interrupt_time = (228*311 - 14357) * 2,
-
-					.delays = {		// Should start at 14361.
-						12, 11,
-						10, 9,
-						8, 7,
-						6, 5,
-						4, 3,
-						2, 1,
-						0, 0,
-						0, 0,
-					}
-				};
-
-				return result;
+			if constexpr (timing == Timing::OneTwoEightK) {
+				constexpr int delays[] = {6, 5, 4, 3, 2, 1, 0, 0};
+				return Timings(228, 311, 4, 128, 14361, delays);
 			}
 
-			if constexpr (timing == VideoTiming::FortyEightK) {
-				constexpr Timings result = {
-					.cycles_per_line = 224 * 2,
-					.lines_per_frame = 312,
-
-					.contention_leadin = 4 * 2,
-					.contention_duration = 128 * 2,
-
-					.interrupt_time = (224*312 - 14331) * 2,
-
-					.delays = {		// Should start at 14335.
-						12, 11,
-						10, 9,
-						8, 7,
-						6, 5,
-						4, 3,
-						2, 1,
-						0, 0,
-						0, 0,
-					}
-				};
-
-				return result;
+			if constexpr (timing == Timing::FortyEightK) {
+				constexpr int delays[] = {6, 5, 4, 3, 2, 1, 0, 0};
+				return Timings(224, 312, 4, 128, 14335, delays);
 			}
 		}
 
-		// TODO: how long is the interrupt line held for?
-		static constexpr int interrupt_duration = 48;
+		// Interrupt should be held for 32 cycles.
+		static constexpr int interrupt_duration = 64;
 
 	public:
 		void run_for(HalfCycles duration) {
 			constexpr auto timings = get_timings();
 
-			constexpr int sync_line = (timings.interrupt_time / timings.cycles_per_line) + 1;
+			constexpr int sync_line = (timings.interrupt_time / timings.half_cycles_per_line) + 1;
 
-			constexpr int sync_position = 166 * 2;
+			constexpr int sync_position = (timing == Timing::FortyEightK) ? 164 * 2 : 166 * 2;
 			constexpr int sync_length = 17 * 2;
 			constexpr int burst_position = sync_position + 40;
 			constexpr int burst_length = 17;
 
 			int cycles_remaining = duration.as<int>();
 			while(cycles_remaining) {
-				int line = time_into_frame_ / timings.cycles_per_line;
-				int offset = time_into_frame_ % timings.cycles_per_line;
-				const int cycles_this_line = std::min(cycles_remaining, timings.cycles_per_line - offset);
+				int line = time_into_frame_ / timings.half_cycles_per_line;
+				int offset = time_into_frame_ % timings.half_cycles_per_line;
+				const int cycles_this_line = std::min(cycles_remaining, timings.half_cycles_per_line - offset);
 				const int end_offset = offset + cycles_this_line;
 
 				if(!offset) {
@@ -292,7 +223,7 @@ template <VideoTiming timing> class Video {
 					if(offset >= burst_position && offset < burst_position+burst_length && end_offset > offset) {
 						const int burst_duration = std::min(burst_position + burst_length, end_offset) - offset;
 
-						if constexpr (timing >= VideoTiming::OneTwoEightK) {
+						if constexpr (timing >= Timing::OneTwoEightK) {
 							crt_.output_colour_burst(burst_duration, 116, is_alternate_line_);
 							// The colour burst phase above is an empirical guess. I need to research further.
 						} else {
@@ -308,7 +239,7 @@ template <VideoTiming timing> class Video {
 				}
 
 				cycles_remaining -= cycles_this_line;
-				time_into_frame_ = (time_into_frame_ + cycles_this_line) % (timings.cycles_per_line * timings.lines_per_frame);
+				time_into_frame_ = (time_into_frame_ + cycles_this_line) % (timings.half_cycles_per_line * timings.lines_per_frame);
 			}
 		}
 
@@ -320,7 +251,7 @@ template <VideoTiming timing> class Video {
 		}
 
 		static constexpr int half_cycles_per_line() {
-			if constexpr (timing == VideoTiming::FortyEightK) {
+			if constexpr (timing == Timing::FortyEightK) {
 				// TODO: determine real figure here, if one exists.
 				// The source I'm looking at now suggests that the theoretical
 				// ideal of 224*2 ignores the real-life effects of separate
@@ -331,6 +262,39 @@ template <VideoTiming timing> class Video {
 			}
 		}
 
+		static constexpr HalfCycles frame_duration() {
+			const auto timings = get_timings();
+			return HalfCycles(timings.half_cycles_per_line * timings.lines_per_frame);
+		}
+
+		HalfCycles time_since_interrupt() {
+			const auto timings = get_timings();
+			if(time_into_frame_ >= timings.interrupt_time) {
+				return HalfCycles(time_into_frame_ - timings.interrupt_time);
+			} else {
+				return HalfCycles(time_into_frame_) + frame_duration() - HalfCycles(timings.interrupt_time);
+			}
+		}
+
+		void set_time_since_interrupt(const HalfCycles time) {
+			// Advance using run_for to ensure that all proper CRT interactions occurred.
+			const auto timings = get_timings();
+			const auto target = (time + timings.interrupt_time) % frame_duration();
+			const auto now = HalfCycles(time_into_frame_);
+
+			// Maybe this is easy?
+			if(target == now) return;
+
+			// Is the time within this frame?
+			if(time > now) {
+				run_for(target - time);
+				return;
+			}
+
+			// Then it's necessary to finish this frame and run into the next.
+			run_for(frame_duration() - now + time);
+		}
+
 	public:
 		Video() :
 			crt_(half_cycles_per_line(), 2, Outputs::Display::Type::PAL50, Outputs::Display::InputDataType::Red2Green2Blue2)
@@ -339,6 +303,11 @@ template <VideoTiming timing> class Video {
 			crt_.set_display_type(Outputs::Display::DisplayType::RGB);
 			crt_.set_visible_area(Outputs::Display::Rect(0.1f, 0.1f, 0.8f, 0.8f));
 
+			// Get the CRT roughly into phase.
+			//
+			// TODO: this is coupled to an assumption about the initial CRT. Fix.
+			const auto timings = get_timings();
+			crt_.output_blank(timings.lines_per_frame*timings.half_cycles_per_line - timings.interrupt_time);
 		}
 
 		void set_video_source(const uint8_t *source) {
@@ -362,7 +331,7 @@ template <VideoTiming timing> class Video {
 			}
 
 			// If not, it'll be in the next batch.
-			return timings.interrupt_time + timings.cycles_per_line * timings.lines_per_frame - time_into_frame_;
+			return timings.interrupt_time + timings.half_cycles_per_line * timings.lines_per_frame - time_into_frame_;
 		}
 
 		/*!
@@ -377,21 +346,22 @@ template <VideoTiming timing> class Video {
 			@returns How many cycles the [ULA/gate array] would delay the CPU for if it were to recognise that contention
 			needs to be applied in @c offset half-cycles from now.
 		*/
-		int access_delay(HalfCycles offset) const {
+		HalfCycles access_delay(HalfCycles offset) const {
 			constexpr auto timings = get_timings();
-			const int delay_time = (time_into_frame_ + offset.as<int>() + timings.contention_leadin) % (timings.cycles_per_line * timings.lines_per_frame);
+			const int delay_time = (time_into_frame_ + offset.as<int>() + timings.contention_leadin) % (timings.half_cycles_per_line * timings.lines_per_frame);
+			assert(!(delay_time&1));
 
 			// Check for a time within the no-contention window.
-			if(delay_time >= (191*timings.cycles_per_line + timings.contention_duration)) {
+			if(delay_time >= (191*timings.half_cycles_per_line + timings.contention_duration)) {
 				return 0;
 			}
 
-			const int time_into_line = delay_time % timings.cycles_per_line;
+			const int time_into_line = delay_time % timings.half_cycles_per_line;
 			if(time_into_line >= timings.contention_duration) {
 				return 0;
 			}
 
-			return timings.delays[time_into_line & 15];
+			return HalfCycles(timings.delays[(time_into_line >> 1) & 7]);
 		}
 
 		/*!
@@ -399,21 +369,21 @@ template <VideoTiming timing> class Video {
 		*/
 		uint8_t get_floating_value() const {
 			constexpr auto timings = get_timings();
-			const uint8_t out_of_bounds = (timing == VideoTiming::Plus3) ? last_contended_access_ : 0xff;
+			const uint8_t out_of_bounds = (timing == Timing::Plus3) ? last_contended_access_ : 0xff;
 
-			const int line = time_into_frame_ / timings.cycles_per_line;
+			const int line = time_into_frame_ / timings.half_cycles_per_line;
 			if(line >= 192) {
 				return out_of_bounds;
 			}
 
-			const int time_into_line = time_into_frame_ % timings.cycles_per_line;
+			const int time_into_line = time_into_frame_ % timings.half_cycles_per_line;
 			if(time_into_line >= 256 || (time_into_line&8)) {
 				return out_of_bounds;
 			}
 
 			// The +2a and +3 always return the low bit as set.
 			const uint8_t value = last_fetches_[(time_into_line >> 1) & 3];
-			if constexpr (timing == VideoTiming::Plus3) {
+			if constexpr (timing == Timing::Plus3) {
 				return value | 1;
 			}
 			return value;
@@ -425,7 +395,7 @@ template <VideoTiming timing> class Video {
 			bus is accessed when the gate array isn't currently reading.
 		*/
 		void set_last_contended_area_access([[maybe_unused]] uint8_t value) {
-			if constexpr (timing == VideoTiming::Plus3) {
+			if constexpr (timing == Timing::Plus3) {
 				last_contended_access_ = value | 1;
 			}
 		}
@@ -434,6 +404,7 @@ template <VideoTiming timing> class Video {
 			Sets the current border colour.
 		*/
 		void set_border_colour(uint8_t colour) {
+			border_byte_ = colour;
 			border_colour_ = palette[colour];
 		}
 
@@ -452,11 +423,17 @@ template <VideoTiming timing> class Video {
 			crt_.set_display_type(type);
 		}
 
+		/*! Gets the display type. */
+		Outputs::Display::DisplayType get_display_type() const {
+			return crt_.get_display_type();
+		}
+
 	private:
 		int time_into_frame_ = 0;
 		Outputs::CRT::CRT crt_;
 		const uint8_t *memory_ = nullptr;
 		uint8_t border_colour_ = 0;
+		uint8_t border_byte_ = 0;
 
 		uint8_t *pixel_target_ = nullptr;
 		int attribute_address_ = 0;
@@ -469,6 +446,8 @@ template <VideoTiming timing> class Video {
 		uint8_t last_fetches_[4] = {0xff, 0xff, 0xff, 0xff};
 		uint8_t last_contended_access_ = 0xff;
 
+		friend struct State;
+
 #define RGB(r, g, b)	(r << 4) | (g << 2) | b
 		static constexpr uint8_t palette[] = {
 			RGB(0, 0, 0),	RGB(0, 0, 2),	RGB(2, 0, 0),	RGB(2, 0, 2),
@@ -479,6 +458,41 @@ template <VideoTiming timing> class Video {
 #undef RGB
 };
 
+struct State: public Reflection::StructImpl<State> {
+	uint8_t border_colour = 0;
+	int half_cycles_since_interrupt = 0;
+	bool flash = 0;
+	int flash_counter = 0;
+	bool is_alternate_line = false;
+
+	State() {
+		if(needs_declare()) {
+			DeclareField(border_colour);
+			DeclareField(half_cycles_since_interrupt);
+			DeclareField(flash);
+			DeclareField(flash_counter);
+			DeclareField(is_alternate_line);
+		}
+	}
+
+	template <typename Video> State(const Video &source) : State() {
+		border_colour = source.border_byte_;
+		flash = source.flash_mask_;
+		flash_counter = source.flash_counter_;
+		is_alternate_line = source. is_alternate_line_;
+		half_cycles_since_interrupt = source.time_since_interrupt().template as<int>();
+	}
+
+	template <typename Video> void apply(Video &target) {
+		target.set_border_colour(border_colour);
+		target.flash_mask_ = flash ? 0xff : 0x00;
+		target.flash_counter_ = flash_counter;
+		target.is_alternate_line_ = is_alternate_line;
+		target.set_time_since_interrupt(HalfCycles(half_cycles_since_interrupt));
+	}
+};
+
+}
 }
 }
 

Machines/Sinclair/ZXSpectrum/ZXSpectrum.cpp

@@ -8,9 +8,9 @@
 
 #include "ZXSpectrum.hpp"
 
+#include "State.hpp"
 #include "Video.hpp"
-
-#define LOG_PREFIX "[Spectrum] "
+#include "../Keyboard/Keyboard.hpp"
 
 #include "../../../Activity/Source.hpp"
 #include "../../MachineTypes.hpp"
@@ -24,7 +24,9 @@
 // just grab the CPC's version of an FDC.
 #include "../../AmstradCPC/FDC.hpp"
 
+#define LOG_PREFIX "[Spectrum] "
 #include "../../../Outputs/Log.hpp"
+
 #include "../../../Outputs/Speaker/Implementation/CompoundSource.hpp"
 #include "../../../Outputs/Speaker/Implementation/LowpassSpeaker.hpp"
 #include "../../../Outputs/Speaker/Implementation/SampleSource.hpp"
@@ -39,12 +41,76 @@
 
 #include "../../../ClockReceiver/JustInTime.hpp"
 
-#include "../../../Processors/Z80/State/State.hpp"
-
-#include "../Keyboard/Keyboard.hpp"
-
 #include <array>
 
+namespace {
+
+/*!
+	Provides a simultaneous Kempston and Interface 2-style joystick.
+*/
+class Joystick: public Inputs::ConcreteJoystick {
+	public:
+		Joystick() :
+			ConcreteJoystick({
+				Input(Input::Up),
+				Input(Input::Down),
+				Input(Input::Left),
+				Input(Input::Right),
+				Input(Input::Fire)
+			}) {}
+
+		void did_set_input(const Input &digital_input, bool is_active) final {
+#define APPLY_KEMPSTON(b)	if(is_active) kempston_ |= b; else kempston_ &= ~b;
+#define APPLY_SINCLAIR(b)	if(is_active) sinclair_ &= ~b; else sinclair_ |= b;
+
+			switch(digital_input.type) {
+				default: return;
+
+				case Input::Right:
+					APPLY_KEMPSTON(0x01);
+					APPLY_SINCLAIR(0x0208);
+				break;
+				case Input::Left:
+					APPLY_KEMPSTON(0x02);
+					APPLY_SINCLAIR(0x0110);
+				break;
+				case Input::Down:
+					APPLY_KEMPSTON(0x04);
+					APPLY_SINCLAIR(0x0404);
+				break;
+				case Input::Up:
+					APPLY_KEMPSTON(0x08);
+					APPLY_SINCLAIR(0x0802);
+				break;
+				case Input::Fire:
+					APPLY_KEMPSTON(0x10);
+					APPLY_SINCLAIR(0x1001);
+				break;
+			}
+
+#undef APPLY_KEMPSTON
+#undef APPLY_SINCLAIR
+		}
+
+		/// @returns The value that a Kempston joystick interface would report if this joystick
+		/// were plugged into it.
+		uint8_t get_kempston() {
+			return kempston_;
+		}
+
+		/// @returns The value that a Sinclair interface would report if this joystick
+		/// were plugged into it via @c port (which should be either 0 or 1, for ports 1 or 2).
+		uint8_t get_sinclair(int port) {
+			return uint8_t(sinclair_ >> (port * 8));
+		}
+
+	private:
+		uint8_t kempston_ = 0x00;
+		uint16_t sinclair_ = 0xffff;
+};
+
+}
+
 namespace Sinclair {
 namespace ZXSpectrum {
 
@@ -58,6 +124,7 @@ template<Model model> class ConcreteMachine:
 	public CPU::Z80::BusHandler,
 	public Machine,
 	public MachineTypes::AudioProducer,
+	public MachineTypes::JoystickMachine,
 	public MachineTypes::MappedKeyboardMachine,
 	public MachineTypes::MediaTarget,
 	public MachineTypes::ScanProducer,
@@ -79,37 +146,32 @@ template<Model model> class ConcreteMachine:
 			set_clock_rate(clock_rate());
 			speaker_.set_input_rate(float(clock_rate()) / 2.0f);
 
-			// With only the +2a and +3 currently supported, the +3 ROM is always
-			// the one required.
-			std::vector<ROMMachine::ROM> rom_names;
-			const std::string machine = "ZXSpectrum";
+			ROM::Name rom_name;
 			switch(model) {
 				case Model::SixteenK:
-				case Model::FortyEightK:
-					rom_names.emplace_back(machine, "the 48kb ROM", "48.rom", 16 * 1024, 0xddee531f);
-				break;
-
-				case Model::OneTwoEightK:
-					rom_names.emplace_back(machine, "the 128kb ROM", "128.rom", 32 * 1024, 0x2cbe8995);
-				break;
-
-				case Model::Plus2:
-					rom_names.emplace_back(machine, "the +2 ROM", "plus2.rom", 32 * 1024, 0xe7a517dc);
-				break;
-
+				case Model::FortyEightK:	rom_name = ROM::Name::Spectrum48k;		break;
+				case Model::OneTwoEightK:	rom_name = ROM::Name::Spectrum128k;		break;
+				case Model::Plus2:			rom_name = ROM::Name::SpecrumPlus2;		break;
 				case Model::Plus2a:
-				case Model::Plus3: {
-					const std::initializer_list<uint32_t> crc32s = { 0x96e3c17a, 0xbe0d9ec4 };
-					rom_names.emplace_back(machine, "the +2a/+3 ROM", "plus3.rom", 64 * 1024, crc32s);
-				} break;
+				case Model::Plus3: 			rom_name = ROM::Name::SpectrumPlus3;	break;
+				// TODO: possibly accept the +3 ROM in multiple parts?
 			}
-			const auto roms = rom_fetcher(rom_names);
-			if(!roms[0]) throw ROMMachine::Error::MissingROMs;
-			memcpy(rom_.data(), roms[0]->data(), std::min(rom_.size(), roms[0]->size()));
+			const auto request = ROM::Request(rom_name);
+			auto roms = rom_fetcher(request);
+			if(!request.validate(roms)) {
+				throw ROMMachine::Error::MissingROMs;
+			}
+
+			const auto &rom = roms.find(rom_name)->second;
+			memcpy(rom_.data(), rom.data(), std::min(rom_.size(), rom.size()));
 
 			// Register for sleeping notifications.
 			tape_player_.set_clocking_hint_observer(this);
 
+			// Attach a couple of joysticks.
+			joysticks_.emplace_back(new Joystick);
+			joysticks_.emplace_back(new Joystick);
+
 			// Set up initial memory map.
 			update_memory_map();
 			set_video_address();
@@ -124,6 +186,29 @@ template<Model model> class ConcreteMachine:
 				duration_to_press_enter_ = Cycles(5 * clock_rate());
 				keyboard_.set_key_state(ZX::Keyboard::KeyEnter, true);
 			}
+
+			// Install state if supplied.
+			if(target.state) {
+				const auto state = static_cast<State *>(target.state.get());
+				state->z80.apply(z80_);
+				state->video.apply(*video_.last_valid());
+				state->ay.apply(ay_);
+
+				// If this is a 48k or 16k machine, remap source data from its original
+				// linear form to whatever the banks end up being; otherwise copy as is.
+				if(model <= Model::FortyEightK) {
+					const size_t num_banks = std::min(size_t(48*1024), state->ram.size()) >> 14;
+					for(size_t c = 0; c < num_banks; c++) {
+						memcpy(&write_pointers_[c + 1][(c+1) * 0x4000], &state->ram[c * 0x4000], 0x4000);
+					}
+				} else {
+					memcpy(ram_.data(), state->ram.data(), std::min(ram_.size(), state->ram.size()));
+
+					port1ffd_ = state->last_1ffd;
+					port7ffd_ = state->last_7ffd;
+					update_memory_map();
+				}
+			}
 		}
 
 		~ConcreteMachine() {
@@ -202,6 +287,10 @@ template<Model model> class ConcreteMachine:
 			video_->set_display_type(display_type);
 		}
 
+		Outputs::Display::DisplayType get_display_type() const override {
+			return video_->get_display_type();
+		}
+
 		// MARK: - BusHandler.
 
 		forceinline HalfCycles perform_machine_cycle(const CPU::Z80::PartialMachineCycle &cycle) {
@@ -218,12 +307,23 @@ template<Model model> class ConcreteMachine:
 					cycle.operation >= PartialMachineCycle::ReadOpcodeStart &&
 					cycle.operation <= PartialMachineCycle::WriteStart) {
 
-					const HalfCycles delay = video_.last_valid()->access_delay(video_.time_since_flush() + HalfCycles(1));
+					const auto delay = video_.last_valid()->access_delay(video_.time_since_flush());
 					advance(cycle.length + delay);
 					return delay;
 				}
 			} else {
 				switch(cycle.operation) {
+					case CPU::Z80::PartialMachineCycle::Input:
+					case CPU::Z80::PartialMachineCycle::Output:
+					case CPU::Z80::PartialMachineCycle::Read:
+					case CPU::Z80::PartialMachineCycle::Write:
+					case CPU::Z80::PartialMachineCycle::ReadOpcode:
+					case CPU::Z80::PartialMachineCycle::Interrupt:
+						// For these, carry on into the actual handler, below.
+					break;
+
+					// For anything else that isn't listed below, just advance
+					// time and conclude here.
 					default:
 						advance(cycle.length);
 					return HalfCycles(0);
@@ -234,7 +334,7 @@ template<Model model> class ConcreteMachine:
 						// always occurs if it is in the $4000–$8000 range regardless of current
 						// memory mapping.
 						HalfCycles delay;
-						HalfCycles time = video_.time_since_flush() + HalfCycles(1);
+						HalfCycles time = video_.time_since_flush();
 
 						if((address & 0xc000) == 0x4000) {
 							for(int c = 0; c < ((address & 1) ? 4 : 2); c++) {
@@ -250,7 +350,7 @@ template<Model model> class ConcreteMachine:
 
 						advance(cycle.length + delay);
 						return delay;
-					}
+					} break;
 
 					case PartialMachineCycle::ReadOpcodeStart:
 					case PartialMachineCycle::ReadStart:
@@ -258,12 +358,12 @@ template<Model model> class ConcreteMachine:
 						// These all start by loading the address bus, then set MREQ
 						// half a cycle later.
 						if(is_contended_[address >> 14]) {
-							const HalfCycles delay = video_.last_valid()->access_delay(video_.time_since_flush() + HalfCycles(1));
+							const auto delay = video_.last_valid()->access_delay(video_.time_since_flush());
 
 							advance(cycle.length + delay);
 							return delay;
 						}
-					}
+					} break;
 
 					case PartialMachineCycle::Internal: {
 						// Whatever's on the address bus will remain there, without IOREQ or
@@ -273,7 +373,7 @@ template<Model model> class ConcreteMachine:
 							const auto half_cycles = cycle.length.as<int>();
 							assert(!(half_cycles & 1));
 
-							HalfCycles time = video_.time_since_flush() + HalfCycles(1);
+							HalfCycles time = video_.time_since_flush();
 							HalfCycles delay;
 							for(int c = 0; c < half_cycles; c += 2) {
 								const auto next_delay = video_.last_valid()->access_delay(time);
@@ -284,15 +384,7 @@ template<Model model> class ConcreteMachine:
 							advance(cycle.length + delay);
 							return delay;
 						}
-					}
-
-					case CPU::Z80::PartialMachineCycle::Input:
-					case CPU::Z80::PartialMachineCycle::Output:
-					case CPU::Z80::PartialMachineCycle::Read:
-					case CPU::Z80::PartialMachineCycle::Write:
-					case CPU::Z80::PartialMachineCycle::ReadOpcode:
-						// For these, carry on into the actual handler, below.
-					break;
+					} break;
 				}
 			}
 
@@ -319,6 +411,7 @@ template<Model model> class ConcreteMachine:
 							break;
 						}
 					}
+					[[fallthrough]];
 
 				case PartialMachineCycle::Read:
 					if constexpr (model == Model::SixteenK) {
@@ -381,10 +474,6 @@ template<Model model> class ConcreteMachine:
 
 						// Set the proper video base pointer.
 						set_video_address();
-
-						// Potentially lock paging, _after_ the current
-						// port values have taken effect.
-						disable_paging_ |= *cycle.value & 0x20;
 					}
 
 					// Test for +2a/+3 paging (i.e. port 1ffd).
@@ -432,6 +521,11 @@ template<Model model> class ConcreteMachine:
 					bool did_match = false;
 					*cycle.value = 0xff;
 
+					if(!(address&32)) {
+						did_match = true;
+						*cycle.value &= static_cast<Joystick *>(joysticks_[0].get())->get_kempston();
+					}
+
 					if(!(address&1)) {
 						did_match = true;
 
@@ -444,11 +538,15 @@ template<Model model> class ConcreteMachine:
 						*cycle.value &= keyboard_.read(address);
 						*cycle.value &= tape_player_.get_input() ? 0xbf : 0xff;
 
-						// If this read is within 200 cycles of the previous,
-						// count it as an adjacent hit; if 20 of those have
-						// occurred then start the tape motor.
+						// Add Joystick input on top.
+						if(!(address&0x1000)) *cycle.value &= static_cast<Joystick *>(joysticks_[0].get())->get_sinclair(0);
+						if(!(address&0x0800)) *cycle.value &= static_cast<Joystick *>(joysticks_[1].get())->get_sinclair(1);
+
+						// If this read is between 50 and 200 cycles since the
+						// previous, count it as an adjacent hit; if 20 of those
+						// have occurred then start the tape motor.
 						if(use_automatic_tape_motor_control_) {
-							if(cycles_since_tape_input_read_ < HalfCycles(400)) {
+							if(cycles_since_tape_input_read_ >= HalfCycles(100) && cycles_since_tape_input_read_ < HalfCycles(200)) {
 								++recent_tape_hits_;
 
 								if(recent_tape_hits_ == 20) {
@@ -496,6 +594,13 @@ template<Model model> class ConcreteMachine:
 						}
 					}
 				} break;
+
+				case PartialMachineCycle::Interrupt:
+					// At least one piece of Spectrum software, Escape from M.O.N.J.A.S. explicitly
+					// assumes that a 0xff value will be on the bus during an interrupt acknowledgment.
+					// I wasn't otherwise aware that this value is reliable.
+					*cycle.value = 0xff;
+				break;
 			}
 
 			return HalfCycles(0);
@@ -513,11 +618,11 @@ template<Model model> class ConcreteMachine:
 			if(!tape_player_is_sleeping_) tape_player_.run_for(duration.as_integral());
 
 			// Update automatic tape motor control, if enabled; if it's been
-			// 3 seconds since software last possibly polled the tape, stop it.
-			if(use_automatic_tape_motor_control_ && cycles_since_tape_input_read_ < HalfCycles(clock_rate() * 6)) {
+			// 0.5 seconds since software last possibly polled the tape, stop it.
+			if(use_automatic_tape_motor_control_ && cycles_since_tape_input_read_ < HalfCycles(clock_rate())) {
 				cycles_since_tape_input_read_ += duration;
 
-				if(cycles_since_tape_input_read_ >= HalfCycles(clock_rate() * 6)) {
+				if(cycles_since_tape_input_read_ >= HalfCycles(clock_rate())) {
 					tape_player_.set_motor_control(false);
 					recent_tape_hits_ = 0;
 				}
@@ -615,6 +720,7 @@ template<Model model> class ConcreteMachine:
 			auto options = std::make_unique<Options>(Configurable::OptionsType::UserFriendly);	// OptionsType is arbitrary, but not optional.
 			options->automatic_tape_motor_control = use_automatic_tape_motor_control_;
 			options->quickload = allow_fast_tape_hack_;
+			options->output = get_video_signal_configurable();
 			return options;
 		}
 
@@ -703,13 +809,17 @@ template<Model model> class ConcreteMachine:
 				set_memory(2, 2);
 				set_memory(3, port7ffd_ & 7);
 			}
+
+			// Potentially lock paging, _after_ the current
+			// port values have taken effect.
+			disable_paging_ = port7ffd_ & 0x20;
 		}
 
 		void set_memory(int bank, uint8_t source) {
 			if constexpr (model >= Model::Plus2a) {
-				is_contended_[bank] = (source >= 4 && source < 8);
+				is_contended_[bank] = source >= 4 && source < 8;
 			} else {
-				is_contended_[bank] = source & 1;
+				is_contended_[bank] = source < 0x80 && source & 1;
 			}
 			pages_[bank] = source;
 
@@ -748,10 +858,10 @@ template<Model model> class ConcreteMachine:
 		// MARK: - Video.
 		using VideoType =
 			std::conditional_t<
-				model <= Model::FortyEightK, Video<VideoTiming::FortyEightK>,
+				model <= Model::FortyEightK, Video::Video<Video::Timing::FortyEightK>,
 				std::conditional_t<
-					model <= Model::Plus2, Video<VideoTiming::OneTwoEightK>,
-					Video<VideoTiming::Plus3>
+					model <= Model::Plus2, Video::Video<Video::Timing::OneTwoEightK>,
+					Video::Video<Video::Timing::Plus3>
 				>
 			>;
 		JustInTimeActor<VideoType> video_;
@@ -862,6 +972,12 @@ template<Model model> class ConcreteMachine:
 
 		// MARK: - Automatic startup.
 		Cycles duration_to_press_enter_;
+
+		// MARK: - Joysticks
+		std::vector<std::unique_ptr<Inputs::Joystick>> joysticks_;
+		const std::vector<std::unique_ptr<Inputs::Joystick>> &get_joysticks() override {
+			return joysticks_;
+		}
 };
 
 

Machines/Sinclair/ZXSpectrum/ZXSpectrum.hpp

@@ -31,7 +31,7 @@ class Machine {
 			friend Configurable::DisplayOption<Options>;
 			friend Configurable::QuickloadOption<Options>;
 			public:
-				bool automatic_tape_motor_control;
+				bool automatic_tape_motor_control = true;
 
 				Options(Configurable::OptionsType type) :
 					Configurable::DisplayOption<Options>(type == Configurable::OptionsType::UserFriendly ? Configurable::Display::RGB : Configurable::Display::CompositeColour),

Machines/StateProducer.hpp

@@ -0,0 +1,26 @@
+//
+//  StateProducer.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 24/04/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#ifndef State_h
+#define State_h
+
+#include <memory>
+#include "../Analyser/Static/StaticAnalyser.hpp"
+
+namespace MachineTypes {
+
+struct StateProducer {
+	// TODO.
+//	virtual bool get_state(Analyser::Static::State *, [[maybe_unused]] bool advance_to_simple = false) {
+//		return false;
+//	}
+};
+
+};
+
+#endif /* State_h */

Machines/Utility/MachineForTarget.cpp

@@ -20,6 +20,7 @@
 #include "../ColecoVision/ColecoVision.hpp"
 #include "../Commodore/Vic-20/Vic20.hpp"
 #include "../Electron/Electron.hpp"
+#include "../Enterprise/Enterprise.hpp"
 #include "../MasterSystem/MasterSystem.hpp"
 #include "../MSX/MSX.hpp"
 #include "../Oric/Oric.hpp"
@@ -34,6 +35,7 @@
 #include "../../Analyser/Static/Atari2600/Target.hpp"
 #include "../../Analyser/Static/AtariST/Target.hpp"
 #include "../../Analyser/Static/Commodore/Target.hpp"
+#include "../../Analyser/Static/Enterprise/Target.hpp"
 #include "../../Analyser/Static/Macintosh/Target.hpp"
 #include "../../Analyser/Static/MSX/Target.hpp"
 #include "../../Analyser/Static/Oric/Target.hpp"
@@ -49,7 +51,7 @@ Machine::DynamicMachine *Machine::MachineForTarget(const Analyser::Static::Targe
 
 	Machine::DynamicMachine *machine = nullptr;
 	try {
-#define BindD(name, m)	case Analyser::Machine::m: machine = new Machine::TypedDynamicMachine<name::Machine>(name::Machine::m(target, rom_fetcher));	break;
+#define BindD(name, m)	case Analyser::Machine::m: machine = new Machine::TypedDynamicMachine<::name::Machine>(name::Machine::m(target, rom_fetcher));	break;
 #define Bind(m)	BindD(m, m)
 		switch(target->machine) {
 			Bind(AmstradCPC)
@@ -61,6 +63,7 @@ Machine::DynamicMachine *Machine::MachineForTarget(const Analyser::Static::Targe
 			BindD(Coleco::Vision, ColecoVision)
 			BindD(Commodore::Vic20, Vic20)
 			Bind(Electron)
+			Bind(Enterprise)
 			Bind(MSX)
 			Bind(Oric)
 			BindD(Sega::MasterSystem, MasterSystem)
@@ -127,6 +130,7 @@ std::string Machine::ShortNameForTargetMachine(const Analyser::Machine machine)
 		case Analyser::Machine::AtariST:		return "AtariST";
 		case Analyser::Machine::ColecoVision:	return "ColecoVision";
 		case Analyser::Machine::Electron:		return "Electron";
+		case Analyser::Machine::Enterprise:		return "Enterprise";
 		case Analyser::Machine::Macintosh:		return "Macintosh";
 		case Analyser::Machine::MasterSystem:	return "MasterSystem";
 		case Analyser::Machine::MSX:			return "MSX";
@@ -148,6 +152,7 @@ std::string Machine::LongNameForTargetMachine(Analyser::Machine machine) {
 		case Analyser::Machine::AtariST:		return "Atari ST";
 		case Analyser::Machine::ColecoVision:	return "ColecoVision";
 		case Analyser::Machine::Electron:		return "Acorn Electron";
+		case Analyser::Machine::Enterprise:		return "Enterprise";
 		case Analyser::Machine::Macintosh:		return "Apple Macintosh";
 		case Analyser::Machine::MasterSystem:	return "Sega Master System";
 		case Analyser::Machine::MSX:			return "MSX";
@@ -177,11 +182,13 @@ std::vector<std::string> Machine::AllMachines(Type type, bool long_names) {
 		AddName(AppleIIgs);
 		AddName(AtariST);
 		AddName(Electron);
+		AddName(Enterprise);
 		AddName(Macintosh);
 		AddName(MSX);
 		AddName(Oric);
 		AddName(Vic20);
 		AddName(ZX8081);
+		AddName(ZXSpectrum);
 	}
 
 #undef AddName
@@ -200,6 +207,7 @@ std::map<std::string, std::unique_ptr<Reflection::Struct>> Machine::AllOptionsBy
 	Emplace(AtariST, Atari::ST::Machine);
 	Emplace(ColecoVision, Coleco::Vision::Machine);
 	Emplace(Electron, Electron::Machine);
+	Emplace(Enterprise, Enterprise::Machine);
 	Emplace(Macintosh, Apple::Macintosh::Machine);
 	Emplace(MasterSystem, Sega::MasterSystem::Machine);
 	Emplace(MSX, MSX::Machine);
@@ -225,6 +233,7 @@ std::map<std::string, std::unique_ptr<Analyser::Static::Target>> Machine::Target
 	Add(AppleIIgs);
 	Add(AtariST);
 	AddMapped(Electron, Acorn);
+	Add(Enterprise);
 	Add(Macintosh);
 	Add(MSX);
 	Add(Oric);

Machines/Utility/MemoryPacker.cpp

@@ -8,6 +8,8 @@
 
 #include "MemoryPacker.hpp"
 
+#include <cstddef>
+
 void Memory::PackBigEndian16(const std::vector<uint8_t> &source, uint16_t *target) {
 	for(size_t c = 0; c < source.size(); c += 2) {
 		target[c >> 1] = uint16_t(source[c] << 8) | uint16_t(source[c+1]);

Machines/Utility/ROMCatalogue.cpp

@@ -0,0 +1,545 @@
+//
+//  ROMCatalogue.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 01/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#include "ROMCatalogue.hpp"
+
+#include <algorithm>
+#include <cassert>
+#include <codecvt>
+#include <iomanip>
+#include <locale>
+#include <sstream>
+
+using namespace ROM;
+
+namespace {
+constexpr Name MaxName = Name::SpectrumPlus3;
+}
+
+Request::Request(Name name, bool optional) {
+	node.name = name;
+	node.is_optional = optional;
+}
+
+Request Request::append(Node::Type type, const Request &rhs) {
+	// If either side is empty, act appropriately.
+	if(node.empty() && !rhs.node.empty()) {
+		return rhs;
+	}
+	if(rhs.node.empty()) {
+		return *this;
+	}
+
+	// Just copy in the RHS child nodes if types match.
+	if(node.type == type && rhs.node.type == type) {
+		Request new_request = *this;
+		new_request.node.children.insert(new_request.node.children.end(), rhs.node.children.begin(), rhs.node.children.end());
+		new_request.node.sort();
+		return new_request;
+	}
+
+	// Possibly: left is appropriate request and rhs is just one more thing?
+	if(node.type == type && rhs.node.type == Node::Type::One) {
+		Request new_request = *this;
+		new_request.node.children.push_back(rhs.node);
+		new_request.node.sort();
+		return new_request;
+	}
+
+	// Or: right is appropriate request and this is just one more thing?
+	if(rhs.node.type == type && node.type == Node::Type::One) {
+		Request new_request = rhs;
+		new_request.node.children.push_back(node);
+		new_request.node.sort();
+		return new_request;
+	}
+
+	// Otherwise create a new parent node.
+	Request parent;
+	parent.node.type = type;
+	parent.node.children.push_back(this->node);
+	parent.node.children.push_back(rhs.node);
+	return parent;
+}
+
+Request Request::operator &&(const Request &rhs) {
+	return append(Node::Type::All, rhs);
+}
+
+Request Request::operator ||(const Request &rhs) {
+	return append(Node::Type::Any, rhs);
+}
+
+bool Request::validate(Map &map) const {
+	return node.validate(map);
+}
+
+std::vector<ROM::Description> Request::all_descriptions() const {
+	std::vector<Description> result;
+	node.add_descriptions(result);
+	return result;
+}
+
+void Request::Node::add_descriptions(std::vector<Description> &result) const {
+	if(type == Type::One) {
+		result.push_back(name);
+		return;
+	}
+
+	for(const auto &child: children) {
+		child.add_descriptions(result);
+	}
+}
+
+Request Request::subtract(const ROM::Map &map) const {
+	Request copy(*this);
+	if(copy.node.subtract(map)) {
+		copy.node.name = Name::None;
+		copy.node.type = Node::Type::One;
+	}
+	return copy;
+}
+
+bool Request::Node::subtract(const ROM::Map &map) {
+	switch(type) {
+		case Type::One:
+		return map.find(name) != map.end();
+
+		default: {
+			bool has_all = true;
+			bool has_any = false;
+
+			auto iterator = children.begin();
+			while(iterator != children.end()) {
+				const bool did_subtract = iterator->subtract(map);
+				has_all &= did_subtract;
+				has_any |= did_subtract;
+				if(did_subtract) {
+					iterator = children.erase(iterator);
+				} else {
+					++iterator;
+				}
+			}
+
+			return (type == Type::All && has_all) || (type == Type::Any && has_any);
+		}
+	}
+}
+
+bool Request::empty() {
+	return node.type == Node::Type::One && node.name == Name::None;
+}
+
+bool Request::Node::validate(Map &map) const {
+	// Leaf nodes are easy: check that the named ROM is present,
+	// unless it's optional, in which case it is always valid.
+	//
+	// If it is present, make sure it's the proper size.
+	if(type == Type::One) {
+		auto rom = map.find(name);
+		if(rom == map.end()) {
+			return is_optional;
+		}
+
+		const Description description(name);
+		rom->second.resize(description.size);
+
+		return true;
+	}
+
+	// This is a collection node then. Check for both any or all
+	// simultaneously, since all nodes will need to be visited
+	// regardless of any/all in order to ensure proper sizing.
+	bool has_all = true;
+	bool has_any = false;
+
+	for(const auto &child: children) {
+		const bool is_valid = child.validate(map);
+		has_all &= is_valid;
+		has_any |= is_valid;
+	}
+
+	return (type == Type::Any && has_any) || (type == Type::All && has_all);
+}
+
+void Request::visit(
+	const std::function<void(ListType, size_t)> &enter_list,
+	const std::function<void(void)> &exit_list,
+	const std::function<void(ROM::Request::ListType, const ROM::Description &, bool, size_t)> &add_item
+) const {
+	node.visit(enter_list, exit_list, add_item);
+}
+
+void Request::visit(
+	const std::function<void(LineItem, ListType, int, const ROM::Description *, bool, size_t)> &add_item
+) const {
+	int indentation_level = 0;
+	node.visit(
+		[&indentation_level, &add_item] (ROM::Request::ListType type, size_t size) {
+			add_item(LineItem::NewList, type, indentation_level, nullptr, false, size);
+			++indentation_level;
+		},
+		[&indentation_level] {
+			--indentation_level;
+		},
+		[&indentation_level, &add_item] (ROM::Request::ListType type, const ROM::Description &rom, bool is_optional, size_t remaining) {
+			add_item(LineItem::Description, type, indentation_level, &rom, is_optional, remaining);
+		}
+	);
+}
+
+void Request::Node::visit(
+	const std::function<void(ListType, size_t)> &enter_list,
+	const std::function<void(void)> &exit_list,
+	const std::function<void(ROM::Request::ListType type, const ROM::Description &, bool is_optional, size_t remaining)> &add_item
+) const {
+	switch(type) {
+		case Type::One:
+			enter_list(ListType::Single, 1);
+			add_item(ROM::Request::ListType::Any, Description(name), is_optional, 0);
+			exit_list();
+		break;
+
+		case Type::Any:
+		case Type::All: {
+			const ListType list_type = type == Type::Any ? ListType::Any : ListType::All;
+			enter_list(list_type, children.size());
+			for(size_t index = 0; index < children.size(); index++) {
+				auto &child = children[index];
+
+				if(child.type == Type::One) {
+					add_item(list_type, Description(child.name), child.is_optional, children.size() - 1 - index);
+				} else {
+					child.visit(enter_list, exit_list, add_item);
+				}
+			}
+			exit_list();
+		} break;
+	}
+}
+
+std::vector<Description> ROM::all_descriptions() {
+	std::vector<Description> result;
+	for(int name = 1; name <= MaxName; name++) {
+		result.push_back(Description(ROM::Name(name)));
+	}
+	return result;
+}
+
+std::optional<Description> Description::from_crc(uint32_t crc32) {
+	for(int name = 1; name <= MaxName; name++) {
+		const Description candidate = Description(ROM::Name(name));
+
+		const auto found_crc = std::find(candidate.crc32s.begin(), candidate.crc32s.end(), crc32);
+		if(found_crc != candidate.crc32s.end()) {
+			return candidate;
+		}
+	}
+
+	return std::nullopt;
+}
+
+std::string Description::description(int flags) const {
+	std::stringstream output;
+
+	// If there are no CRCs, don't output them.
+	if(crc32s.empty()) flags &= ~ DescriptionFlag::CRC;
+
+	// Print the file name(s) and the descriptive name.
+	if(flags & DescriptionFlag::Filename) {
+		flags &= ~DescriptionFlag::Filename;
+
+		output << machine_name <<  '/';
+		if(file_names.size() == 1) {
+			output << file_names[0];
+		} else {
+			output << "{";
+			bool is_first = true;
+			for(const auto &file_name: file_names) {
+				if(!is_first) output << " or ";
+				output << file_name;
+				is_first = false;
+			}
+			output << "}";
+		}
+		output << " (" << descriptive_name;
+		if(!flags) {
+			output << ")";
+			return output.str();
+		}
+		output << "; ";
+	} else {
+		output << descriptive_name;
+		if(!flags) {
+			return output.str();
+		}
+		output << " (";
+	}
+
+	// Print the size.
+	if(flags & DescriptionFlag::Size) {
+		flags &= ~DescriptionFlag::Size;
+		output << size << " bytes";
+
+		if(!flags) {
+			output << ")";
+			return output.str();
+		}
+		output << "; ";
+	}
+
+	// Print the CRC(s).
+	if(flags & DescriptionFlag::CRC) {
+		flags &= ~DescriptionFlag::CRC;
+
+		output << ((crc32s.size() > 1) ? "usual crc32s: " : "usual crc32: ");
+		bool is_first = true;
+		for(const auto crc32: crc32s) {
+			if(!is_first) output << ", ";
+			is_first = false;
+			output << std::hex << std::setfill('0') << std::setw(8) << crc32;
+		}
+
+		if(!flags) {
+			output << ")";
+			return output.str();
+		}
+	}
+
+	return output.str();
+}
+
+std::wstring Request::description(int description_flags, wchar_t bullet_point) {
+	std::wstringstream output;
+	std::wstring_convert<std::codecvt_utf8<wchar_t>> wstring_converter;
+
+	visit(
+		[&output, description_flags, bullet_point, &wstring_converter] (ROM::Request::LineItem item, ROM::Request::ListType type, int indentation_level, const ROM::Description *description, bool is_optional, size_t remaining) {
+			if(indentation_level) {
+				output << std::endl;
+				for(int c = 0; c < indentation_level; c++) output << '\t';
+				output << bullet_point << ' ';
+			}
+
+			switch(item) {
+				case ROM::Request::LineItem::NewList:
+					if(remaining > 1) {
+						if(!indentation_level) output << " ";
+						switch(type) {
+							default:
+							case ROM::Request::ListType::All:	output << "all of:";		break;
+							case ROM::Request::ListType::Any:
+								if(remaining == 2) {
+									output << "either of:";
+								} else {
+									output << "any of:";
+								}
+							break;
+						}
+					} else {
+						output << ":";
+					}
+				break;
+
+				case ROM::Request::LineItem::Description:
+					if(is_optional) output << "optionally, ";
+
+					output << wstring_converter.from_bytes(description->description(description_flags));
+
+					if(remaining) {
+						output << ";";
+						if(remaining == 1) {
+							output << ((type == ROM::Request::ListType::All) ? " and" : " or");
+						}
+					} else {
+						output << ".";
+					}
+				break;
+			}
+		}
+	);
+
+	return output.str();
+}
+
+
+Description::Description(Name name) {
+	switch(name) {
+		default: assert(false);	break;
+
+		case Name::AMSDOS:				*this = Description(name, "AmstradCPC", "the Amstrad Disk Operating System", "amsdos.rom", 16*1024, 0x1fe22ecdu);	break;
+		case Name::CPC464Firmware:		*this = Description(name, "AmstradCPC", "the CPC 464 firmware", "os464.rom", 16*1024, 0x815752dfu);					break;
+		case Name::CPC464BASIC:			*this = Description(name, "AmstradCPC", "the CPC 464 BASIC ROM", "basic464.rom", 16*1024, 0x7d9a3bacu);				break;
+		case Name::CPC664Firmware:		*this = Description(name, "AmstradCPC", "the CPC 664 firmware", "os664.rom", 16*1024, 0x3f5a6dc4u);					break;
+		case Name::CPC664BASIC:			*this = Description(name, "AmstradCPC", "the CPC 664 BASIC ROM", "basic664.rom", 16*1024, 0x32fee492u);				break;
+		case Name::CPC6128Firmware:		*this = Description(name, "AmstradCPC", "the CPC 6128 firmware", "os6128.rom", 16*1024, 0x0219bb74u);				break;
+		case Name::CPC6128BASIC:		*this = Description(name, "AmstradCPC", "the CPC 6128 BASIC ROM", "basic6128.rom", 16*1024, 0xca6af63du);			break;
+
+		case Name::AppleIIEnhancedE:	*this = Description(name, "AppleII", "the Enhanced Apple IIe ROM", "apple2e.rom", 32*1024, 0x65989942u);				break;
+		case Name::AppleIIe:			*this = Description(name, "AppleII", "the Apple IIe ROM", "apple2eu.rom", 32*1024, 0xe12be18du);						break;
+		case Name::AppleIIPlus:			*this = Description(name, "AppleII", "the Apple II+ ROM", "apple2.rom", 12*1024, 0xf66f9c26u);							break;
+		case Name::AppleIIOriginal:		*this = Description(name, "AppleII", "the original Apple II ROM", "apple2o.rom", 12*1024, 0xba210588u);					break;
+		case Name::AppleIICharacter:	*this = Description(name, "AppleII", "the basic Apple II character ROM", "apple2-character.rom", 2*1024, 0x64f415c6u);	break;
+		case Name::AppleIIeCharacter:	*this = Description(name, "AppleII", "the Apple IIe character ROM", "apple2eu-character.rom", 4*1024, 0x816a86f1u);		break;
+		case Name::AppleIIEnhancedECharacter:
+			*this = Description(name, "AppleII", "the Enhanced Apple IIe character ROM", "apple2e-character.rom", 4*1024, 0x2651014du);
+		break;
+
+		case Name::AppleIIgsROM00:	/* TODO */
+		case Name::AppleIIgsROM01:		*this = Description(name, "AppleIIgs", "the Apple IIgs ROM01", "apple2gs.rom", 128*1024, 0x42f124b0u);			break;
+		case Name::AppleIIgsROM03:		*this = Description(name, "AppleIIgs", "the Apple IIgs ROM03", "apple2gs.rom2", 256*1024, 0xde7ddf29u);			break;
+		case Name::AppleIIgsCharacter:	*this = Description(name, "AppleIIgs", "the Apple IIgs character ROM", "apple2gs.chr", 4*1024, 0x91e53cd8u);	break;
+		case AppleIIgsMicrocontrollerROM03:
+			*this = Description(name, "AppleIIgs", "the Apple IIgs ROM03 ADB microcontroller ROM", "341s0632-2", 4*1024, 0xe1c11fb0u);
+		break;
+
+		case Name::DiskIIBoot16Sector:
+			*this = Description(name, "DiskII", "the Disk II 16-sector boot ROM", "boot-16.rom", 256, 0xce7144f6u);
+		break;
+		case Name::DiskIIStateMachine16Sector:
+			*this = Description(name, "DiskII", "the Disk II 16-sector state machine ROM", "state-machine-16.rom", 256, std::initializer_list<uint32_t>{ 0x9796a238, 0xb72a2c70 } );
+		break;
+		case Name::DiskIIBoot13Sector:
+			*this = Description(name, "DiskII", "the Disk II 13-sector boot ROM", "boot-13.rom", 256, 0xd34eb2ffu);
+		break;
+		case Name::DiskIIStateMachine13Sector:
+			*this = Description(name, "DiskII", "the Disk II 13-sector state machine ROM", "state-machine-13.rom", 256, 0x62e22620u);
+		break;
+
+		case Name::EnterpriseEXOS10: {
+			const std::initializer_list<std::string> filenames = {"exos10.bin", "Exos (198x)(Enterprise).bin"};
+			*this = Description(name, "Enterprise", "the Enterprise EXOS ROM v1.0", filenames, 32 * 1024, 0x30b26387u);
+		} break;
+		case Name::EnterpriseEXOS20: {
+			const std::initializer_list<std::string> filenames = {"exos20.bin", "Expandible OS v2.0 (1984)(Intelligent Software).bin"};
+			*this = Description(name, "Enterprise", "the Enterprise EXOS ROM v2.0", filenames, 32 * 1024, 0xd421795fu);
+		} break;
+		case Name::EnterpriseEXOS21: {
+			const std::initializer_list<std::string> filenames = {"exos21.bin", "Expandible OS v2.1 (1985)(Intelligent Software).bin"};
+			*this = Description(name, "Enterprise", "the Enterprise EXOS ROM v2.1", filenames, 32 * 1024, 0x982a3b44u);
+		} break;
+		case Name::EnterpriseEXOS23: {
+			const std::initializer_list<std::string> filenames = {"exos23.bin", "Expandible OS v2.3 (1987)(Intelligent Software).bin"};
+			*this = Description(name, "Enterprise", "the Enterprise EXOS ROM v2.1", filenames, 64 * 1024, 0x24838410u);
+		} break;
+
+		case Name::EnterpriseBASIC10: {
+			const std::initializer_list<std::string> filenames = {"basic10.bin"};
+			*this = Description(name, "Enterprise", "the Enterprise BASIC ROM v1.0", filenames, 16 * 1024, 0xd62e4fb7u);
+		} break;
+		case Name::EnterpriseBASIC10Part1: {
+			const std::initializer_list<std::string> filenames = {"BASIC 1.0 - EPROM 1-2 (198x)(Enterprise).bin"};
+			*this = Description(name, "Enterprise", "the Enterprise BASIC ROM v1.0, Part 1", filenames, 8193, 0x37bf48e1u);
+		} break;
+		case Name::EnterpriseBASIC10Part2: {
+			const std::initializer_list<std::string> filenames = {"BASIC 1.0 - EPROM 2-2 (198x)(Enterprise).bin"};
+			*this = Description(name, "Enterprise", "the Enterprise BASIC ROM v1.0, Part 2", filenames, 8193, 0xc5298c79u);
+		} break;
+		case Name::EnterpriseBASIC11: {
+			const std::initializer_list<std::string> filenames = {"basic11.bin"};
+			*this = Description(name, "Enterprise", "the Enterprise BASIC ROM v1.1", filenames, 16 * 1024, 0x683cf455u);
+		} break;
+		case Name::EnterpriseBASIC11Suffixed: {
+			const std::initializer_list<std::string> filenames = {"BASIC 1.1 - EPROM 1.1 (198x)(Enterprise).bin"};
+			*this = Description(name, "Enterprise", "the Enterprise BASIC ROM v1.1, with trailing byte", filenames, 16385, 0xc96b7602u);
+		} break;
+		case Name::EnterpriseBASIC21: {
+			const std::initializer_list<std::string> filenames = {
+				"basic21.bin",
+				"BASIC Interpreter v2.1 (1985)(Intelligent Software).bin",
+				"BASIC Interpreter v2.1 (1985)(Intelligent Software)[a].bin"
+			};
+			const std::initializer_list<uint32_t> crcs = { 0x55f96251, 0x683cf455 };
+			*this = Description(name, "Enterprise", "the Enterprise BASIC ROM v2.1", filenames, 16 * 1024, crcs);
+		} break;
+
+		case Name::EnterpriseEPDOS: {
+			const std::initializer_list<std::string> filenames = {"epdos.bin", "EPDOS v1.7 (19xx)(Haluska, Laszlo).bin"};
+			*this = Description(name, "Enterprise", "the Enterprise EPDOS ROM", filenames, 32 * 1024, 0x201319ebu);
+		} break;
+		case Name::EnterpriseEXDOS: {
+			const std::initializer_list<std::string> filenames = {"exdos.bin", "EX-DOS EPROM (198x)(Enterprise).bin"};
+			*this = Description(name, "Enterprise", "the Enterprise EXDOS ROM", filenames, 16 * 1024, 0xe6daa0e9u);
+		} break;
+
+		case Name::Macintosh128k:	*this = Description(name, "Macintosh", "the Macintosh 128k ROM", "mac128k.rom", 64*1024, 0x6d0c8a28u);	break;
+		case Name::Macintosh512k:	*this = Description(name, "Macintosh", "the Macintosh 512k ROM", "mac512k.rom", 64*1024, 0xcf759e0d);	break;
+		case Name::MacintoshPlus: {
+			const std::initializer_list<uint32_t> crcs = { 0x4fa5b399, 0x7cacd18f, 0xb2102e8e };
+			*this = Description(name, "Macintosh", "the Macintosh Plus ROM", "macplus.rom", 128*1024, crcs);
+		} break;
+
+		case Name::AtariSTTOS100:		*this = Description(name, "AtariST", "the UK TOS 1.00 ROM", "tos100.img", 192*1024, 0x1a586c64u);		break;
+		case Name::AtariSTTOS104:		*this = Description(name, "AtariST", "the UK TOS 1.04 ROM", "tos104.img", 192*1024, 0xa50d1d43u);		break;
+		case Name::AtariSTEmuTOS192:	*this = Description(name, "AtariST", "the UK EmuTOS 1.92 ROM", "etos192uk.img", 192*1024, 0xfc3b9e61u);	break;
+
+		case Name::ColecoVisionBIOS:
+			*this = Description(name, "ColecoVision", "the ColecoVision BIOS", "coleco.rom", 8*1024, 0x3aa93ef3u);
+		break;
+
+		case Name::ZX80:	*this = Description(name, "ZX8081", "the ZX80 BASIC ROM", "zx80.rom", 4 * 1024, 0x4c7fc597u);	break;
+		case Name::ZX81:	*this = Description(name, "ZX8081", "the ZX81 BASIC ROM", "zx81.rom", 8 * 1024, 0x4b1dd6ebu);	break;
+
+		case Name::Spectrum48k:		*this = Description(name, "ZXSpectrum", "the 48kb ROM", "48.rom", 16 * 1024, 0xddee531fu);		break;
+		case Name::Spectrum128k:	*this = Description(name, "ZXSpectrum", "the 128kb ROM", "128.rom", 32 * 1024, 0x2cbe8995u);	break;
+		case Name::SpecrumPlus2:	*this = Description(name, "ZXSpectrum", "the +2 ROM", "plus2.rom", 32 * 1024, 0xe7a517dcu); 	break;
+		case Name::SpectrumPlus3: {
+			const std::initializer_list<uint32_t> crcs = { 0x96e3c17a, 0xbe0d9ec4 };
+			*this = Description(name, "ZXSpectrum", "the +2a/+3 ROM", "plus3.rom", 64 * 1024, crcs);
+		} break;
+
+		case Name::AcornBASICII:	*this = Description(name, "Electron", "the Acorn BASIC II ROM", "basic.rom", 16*1024, 0x79434781u); 			break;
+		case Name::PRESADFSSlot1:	*this = Description(name, "Electron", "the E00 ADFS ROM, first slot", "ADFS-E00_1.rom", 16*1024, 0x51523993u); 	break;
+		case Name::PRESADFSSlot2:	*this = Description(name, "Electron", "the E00 ADFS ROM, second slot", "ADFS-E00_2.rom", 16*1024, 0x8d17de0eu); break;
+		case Name::AcornADFS:		*this = Description(name, "Electron", "the Acorn ADFS ROM", "adfs.rom", 16*1024, 0x3289bdc6u); 					break;
+		case Name::Acorn1770DFS:	*this = Description(name, "Electron", "the 1770 DFS ROM", "DFS-1770-2.20.rom", 16*1024, 0xf3dc9bc5u);			break;
+		case Name::PRESAdvancedPlus6:
+			*this = Description(name, "Electron", "the 8kb Advanced Plus 6 ROM", "AP6v133.rom", 8*1024, 0xe0013cfcu);
+		break;
+		case Name::AcornElectronMOS100:
+			*this = Description(name, "Electron", "the Electron MOS ROM v1.00", "os.rom", 16*1024, 0xbf63fb1fu);
+		break;
+
+		case Name::MasterSystemJapaneseBIOS:	*this = Description(name, "MasterSystem", "the Japanese Master System BIOS", "japanese-bios.sms", 8*1024, 0x48d44a13u); break;
+		case Name::MasterSystemWesternBIOS:		*this = Description(name, "MasterSystem", "the European/US Master System BIOS", "bios.sms", 8*1024, 0x0072ed54u); 		break;
+
+		case Name::Commodore1540:	*this = Description(name, "Commodore1540", "the 1540 ROM", "1540.bin", 16*1024, 0x718d42b1u);	break;
+		case Name::Commodore1541:	*this = Description(name, "Commodore1540", "the 1541 ROM", "1541.bin", 16*1024, 0xfb760019);	break;
+
+		case Name::Vic20BASIC:				*this = Description(name, "Vic20", "the VIC-20 BASIC ROM", "basic.bin", 8*1024, 0xdb4c43c1u);									break;
+		case Name::Vic20EnglishCharacters:	*this = Description(name, "Vic20", "the English-language VIC-20 character ROM", "characters-english.bin", 4*1024, 0x83e032a6u);	break;
+		case Name::Vic20EnglishPALKernel:	*this = Description(name, "Vic20", "the English-language PAL VIC-20 kernel ROM", "kernel-pal.bin", 8*1024, 0x4be07cb4u);		break;
+		case Name::Vic20EnglishNTSCKernel:	*this = Description(name, "Vic20", "the English-language NTSC VIC-20 kernel ROM", "kernel-ntsc.bin", 8*1024, 0xe5e7c174u);		break;
+		case Name::Vic20DanishCharacters:	*this = Description(name, "Vic20", "the Danish VIC-20 character ROM", "characters-danish.bin", 4*1024, 0x7fc11454u);			break;
+		case Name::Vic20DanishKernel:		*this = Description(name, "Vic20", "the Danish VIC-20 kernel ROM", "kernel-danish.bin", 8*1024, 0x02adaf16u);					break;
+		case Name::Vic20JapaneseCharacters:	*this = Description(name, "Vic20", "the Japanese VIC-20 character ROM", "characters-japanese.bin", 4*1024, 0xfcfd8a4bu);		break;
+		case Name::Vic20JapaneseKernel:		*this = Description(name, "Vic20", "the Japanese VIC-20 kernel ROM", "kernel-japanese.bin", 8*1024, 0x336900d7u);				break;
+		case Name::Vic20SwedishCharacters:	*this = Description(name, "Vic20", "the Swedish VIC-20 character ROM", "characters-swedish.bin", 4*1024, 0xd808551du);			break;
+		case Name::Vic20SwedishKernel:		*this = Description(name, "Vic20", "the Swedish VIC-20 kernel ROM", "kernel-swedish.bin", 8*1024, 0xb2a60662u);					break;
+
+		case Name::OricColourROM:		*this = Description(name, "Oric", "the Oric colour ROM", "colour.rom", 128, 0xd50fca65u);			break;
+		case Name::OricBASIC10:			*this = Description(name, "Oric", "Oric BASIC 1.0", "basic10.rom", 16*1024, 0xf18710b4u);			break;
+		case Name::OricBASIC11:			*this = Description(name, "Oric", "Oric BASIC 1.1", "basic11.rom", 16*1024, 0xc3a92befu);			break;
+		case Name::OricPravetzBASIC:	*this = Description(name, "Oric", "Pravetz BASIC", "pravetz.rom", 16*1024, 0x58079502u);			break;
+		case Name::OricByteDrive500:	*this = Description(name, "Oric", "the Oric Byte Drive 500 ROM", "bd500.rom", 8*1024, 0x61952e34u);	break;
+		case Name::OricJasmin:			*this = Description(name, "Oric", "the Oric Jasmin ROM", "jasmin.rom", 2*1024, 0x37220e89u);		break;
+		case Name::OricMicrodisc:		*this = Description(name, "Oric", "the Oric Microdisc ROM", "microdisc.rom", 8*1024, 0xa9664a9cu);	break;
+		case Name::Oric8DOSBoot:		*this = Description(name, "Oric", "the 8DOS boot ROM", "8dos.rom", 512, 0x49a74c06u);				break;
+
+		case Name::MSXGenericBIOS:	*this = Description(name, "MSX", "any MSX BIOS", "msx.rom", 32*1024, 0x94ee12f3u);					break;
+		case Name::MSXJapaneseBIOS:	*this = Description(name, "MSX", "a Japanese MSX BIOS", "msx-japanese.rom", 32*1024, 0xee229390u);	break;
+		case Name::MSXAmericanBIOS:	*this = Description(name, "MSX", "an American MSX BIOS", "msx-american.rom", 32*1024, 0u);			break;
+		case Name::MSXEuropeanBIOS:	*this = Description(name, "MSX", "a European MSX BIOS", "msx-european.rom", 32*1024, 0u);			break;
+		case Name::MSXDOS:			*this = Description(name, "MSX", "the MSX-DOS ROM", "disk.rom", 16*1024, 0x721f61dfu);				break;
+
+		case Name::SinclairQLJS:
+			*this = Description(name, "SinclairQL", "the Sinclair QL 'JS' ROM", "js.rom", 48*1024, 0x0f95aab5u);
+		break;
+
+	}
+}

Machines/Utility/ROMCatalogue.hpp

@@ -0,0 +1,289 @@
+//
+//  ROMCatalogue.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 01/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#ifndef ROMCatalogue_hpp
+#define ROMCatalogue_hpp
+
+#include <algorithm>
+#include <functional>
+#include <map>
+#include <optional>
+#include <set>
+#include <string>
+#include <vector>
+
+namespace ROM {
+
+enum Name {
+	None,
+
+	// Acorn.
+	AcornBASICII,
+	AcornElectronMOS100,
+	PRESADFSSlot1,
+	PRESADFSSlot2,
+	AcornADFS,
+	PRESAdvancedPlus6,
+	Acorn1770DFS,
+
+	// Amstrad CPC.
+	AMSDOS,
+	CPC464Firmware,		CPC464BASIC,
+	CPC664Firmware,		CPC664BASIC,
+	CPC6128Firmware,	CPC6128BASIC,
+
+	// Apple II.
+	AppleIIOriginal,
+	AppleIIPlus,
+	AppleIICharacter,
+	AppleIIe,
+	AppleIIeCharacter,
+	AppleIIEnhancedE,
+	AppleIIEnhancedECharacter,
+
+	// Apple IIgs.
+	AppleIIgsROM00,
+	AppleIIgsROM01,
+	AppleIIgsROM03,
+	AppleIIgsMicrocontrollerROM03,
+	AppleIIgsCharacter,
+
+	// Atari ST.
+	AtariSTTOS100,
+	AtariSTTOS104,
+	AtariSTEmuTOS192,
+
+	// ColecoVision.
+	ColecoVisionBIOS,
+
+	// Commodore 1540/1541.
+	Commodore1540,
+	Commodore1541,
+
+	// Disk II.
+	DiskIIStateMachine16Sector,
+	DiskIIBoot16Sector,
+	DiskIIStateMachine13Sector,
+	DiskIIBoot13Sector,
+
+	// Enterprise.
+	EnterpriseEXOS10,
+	EnterpriseEXOS20,
+	EnterpriseEXOS21,
+	EnterpriseEXOS23,
+
+	EnterpriseBASIC10,
+	EnterpriseBASIC10Part1,
+	EnterpriseBASIC10Part2,
+	EnterpriseBASIC11,
+	EnterpriseBASIC11Suffixed,
+	EnterpriseBASIC21,
+
+	EnterpriseEPDOS,
+	EnterpriseEXDOS,
+
+	// Macintosh.
+	Macintosh128k,
+	Macintosh512k,
+	MacintoshPlus,
+
+	// Master System.
+	MasterSystemJapaneseBIOS,
+	MasterSystemWesternBIOS,
+
+	// MSX.
+	MSXGenericBIOS,
+	MSXJapaneseBIOS,
+	MSXAmericanBIOS,
+	MSXEuropeanBIOS,
+	MSXDOS,
+
+	// Oric.
+	OricColourROM,
+	OricBASIC10,
+	OricBASIC11,
+	OricPravetzBASIC,
+	OricByteDrive500,
+	OricJasmin,
+	OricMicrodisc,
+	Oric8DOSBoot,
+
+	// Sinclair QL.
+	SinclairQLJS,
+
+	// Vic-20.
+	Vic20BASIC,
+	Vic20EnglishCharacters,
+	Vic20EnglishPALKernel,
+	Vic20EnglishNTSCKernel,
+	Vic20DanishCharacters,
+	Vic20DanishKernel,
+	Vic20JapaneseCharacters,
+	Vic20JapaneseKernel,
+	Vic20SwedishCharacters,
+	Vic20SwedishKernel,
+
+	// ZX80/81.
+	ZX80,
+	ZX81,
+
+	// ZX Spectrum.
+	Spectrum48k,
+	Spectrum128k,
+	SpecrumPlus2,
+	SpectrumPlus3,
+
+};
+
+using Map = std::map<ROM::Name, std::vector<uint8_t>>;
+
+struct Description {
+	/// The ROM's enum name.
+	Name name = Name::None;
+	/// The machine with which this ROM is associated, in a form that is safe for using as
+	/// part of a file name.
+	std::string machine_name;
+	/// A descriptive name for this ROM, suitable for use in a bullet-point list, a bracket
+	/// clause, etc, e.g. "the Electron MOS 1.0".
+	std::string descriptive_name;
+	/// All idiomatic file name for this ROM, e.g. "os10.rom".
+	std::vector<std::string> file_names;
+	/// The expected size of this ROM in bytes, e.g. 32768.
+	size_t size = 0;
+	/// CRC32s for all known acceptable copies of this ROM; intended to allow a host platform
+	/// to test user-provided ROMs of unknown provenance. **Not** intended to be used
+	/// to exclude ROMs where the user's intent is otherwise clear.
+	std::set<uint32_t> crc32s;
+
+	/// Constructs the @c Description that correlates to @c name.
+	Description(Name name);
+
+	/// Constructs the @c Description that correlates to @c crc32, if any.
+	static std::optional<Description> from_crc(uint32_t crc32);
+
+	enum DescriptionFlag {
+		Size = 1 << 0,
+		CRC = 1 << 1,
+		Filename = 1 << 2,
+	};
+
+	/// Provides a single-line of text describing this ROM, including the usual base text
+	/// plus all the fields provided as @c flags .
+	std::string description(int flags) const;
+
+	private:
+		template <typename FileNameT, typename CRC32T> Description(
+			Name name, std::string machine_name, std::string descriptive_name, FileNameT file_names, size_t size, CRC32T crc32s = uint32_t(0)
+		) : name{name}, machine_name{machine_name}, descriptive_name{descriptive_name}, file_names{file_names}, size{size}, crc32s{crc32s} {
+			// Slightly lazy: deal with the case where the constructor wasn't provided with any
+			// CRCs by spotting that the set has exactly one member, which has value 0. The alternative
+			// would be to provide a partial specialisation that never put anything into the set.
+			if(this->crc32s.size() == 1 && !*this->crc32s.begin()) {
+				this->crc32s.clear();
+			}
+		}
+};
+
+/// @returns a vector of all possible instances of ROM::Description — i.e. descriptions of every ROM
+/// currently known to the ROM catalogue.
+std::vector<Description> all_descriptions();
+
+struct Request {
+	Request(Name name, bool optional = false);
+	Request() {}
+
+	/// Forms the request that would be satisfied by @c this plus the right-hand side.
+	Request operator &&(const Request &);
+
+	/// Forms the request that would be satisfied by either @c this or the right-hand side.
+	Request operator ||(const Request &);
+
+	/// Inspects the ROMMap to ensure that it satisfies this @c Request.
+	/// @c returns @c true if the request is satisfied; @c false otherwise.
+	///
+	/// All ROMs in the map will be resized to their idiomatic sizes.
+	bool validate(Map &) const;
+
+	/// Returns a flattened array of all @c ROM::Descriptions that relate to anything
+	/// anywhere in this ROM request.
+	std::vector<Description> all_descriptions() const;
+
+	/// @returns @c true if this request is empty, i.e. would be satisfied with no ROMs; @c false otherwise.
+	bool empty();
+
+	/// @returns what remains of this ROM request given that everything in @c map has been found.
+	Request subtract(const ROM::Map &map) const;
+
+	enum class ListType {
+		Any, All, Single
+	};
+	void visit(
+		const std::function<void(ListType, size_t size)> &enter_list,
+		const std::function<void(void)> &exit_list,
+		const std::function<void(ROM::Request::ListType type, const ROM::Description &, bool is_optional, size_t remaining)> &add_item
+	) const;
+
+	enum class LineItem {
+		NewList, Description
+	};
+	void visit(
+		const std::function<void(LineItem, ListType, int level, const ROM::Description *, bool is_optional, size_t remaining)> &add_item
+	) const;
+
+	/// @returns a full bullet-pointed list of the requirements of this request, including
+	/// appropriate conjuntives. This text is intended to be glued to the end of an opening
+	/// portion of a sentence, e.g. "Please supply" + request.description(0, L'*').
+	std::wstring description(int description_flags, wchar_t bullet_point);
+
+	private:
+		struct Node {
+			enum class Type {
+				Any, All, One
+			};
+			Type type = Type::One;
+			Name name = Name::None;
+			/// @c true if this ROM is optional for machine startup. Generally indicates something
+			/// that would make emulation more accurate, but not sufficiently so to make it
+			/// a necessity.
+			bool is_optional = false;
+			std::vector<Node> children;
+
+			bool empty() const {
+				return type == Type::One && name == Name::None;
+			}
+
+			void add_descriptions(std::vector<Description> &) const;
+			bool validate(Map &) const;
+			void visit(
+				const std::function<void(ListType, size_t)> &enter_list,
+				const std::function<void(void)> &exit_list,
+				const std::function<void(ROM::Request::ListType type, const ROM::Description &, bool is_optional, size_t remaining)> &add_item
+			) const;
+			bool subtract(const ROM::Map &map);
+			void sort() {
+				// Don't do a full sort, but move anything optional to the back.
+				// This makes them print more nicely; it's a human-facing tweak only.
+				ssize_t index = ssize_t(children.size() - 1);
+				bool has_seen_non_optional = false;
+				while(index >= 0) {
+					has_seen_non_optional |= !children[size_t(index)].is_optional;
+					if(children[size_t(index)].is_optional && has_seen_non_optional) {
+						std::rotate(children.begin() + index, children.begin() + index + 1, children.end());
+					}
+					--index;
+				}
+			}
+		};
+		Node node;
+
+		Request append(Node::Type type, const Request &rhs);
+};
+
+}
+
+#endif /* ROMCatalogue_hpp */

Machines/Utility/Typer.cpp

@@ -131,13 +131,3 @@ bool Typer::type_next_character() {
 
 	return true;
 }
-
-// MARK: - Character mapper
-
-const uint16_t *CharacterMapper::table_lookup_sequence_for_character(const KeySequence *sequences, std::size_t length, char character) const {
-	std::size_t ucharacter = size_t((unsigned char)character);
-	if(ucharacter >= (length / sizeof(KeySequence))) return nullptr;
-	if(sequences[ucharacter][0] == MachineTypes::MappedKeyboardMachine::KeyNotMapped) return nullptr;
-	return sequences[ucharacter];
-}
-

Machines/Utility/Typer.hpp

@@ -44,11 +44,15 @@ class CharacterMapper {
 		typedef uint16_t KeySequence[16];
 
 		/*!
-			Provided in the base class as a convenience: given the lookup table of key sequences @c sequences,
-			with @c length entries, returns the sequence for character @c character if it exists; otherwise
-			returns @c nullptr.
+			Provided in the base class as a convenience: given the C array of key sequences @c sequences,
+			returns the sequence for character @c character if it exists; otherwise returns @c nullptr.
 		*/
-		const uint16_t *table_lookup_sequence_for_character(const KeySequence *sequences, std::size_t length, char character) const;
+		template <typename Collection> const uint16_t *table_lookup_sequence_for_character(const Collection &sequences, char character) const {
+			std::size_t ucharacter = size_t((unsigned char)character);
+			if(ucharacter >= sizeof(sequences) / sizeof(KeySequence)) return nullptr;
+			if(sequences[ucharacter][0] == MachineTypes::MappedKeyboardMachine::KeyNotMapped) return nullptr;
+			return sequences[ucharacter];
+		}
 };
 
 /*!

Numeric/LFSR.hpp

@@ -12,6 +12,8 @@
 #include <cstdint>
 #include <cstdlib>
 
+#include "Sizes.hpp"
+
 namespace Numeric {
 
 template <typename IntType> struct LSFRPolynomial {};
@@ -67,8 +69,8 @@ template <typename IntType = uint64_t, IntType polynomial = LSFRPolynomial<IntTy
 			determining the bit that was just shifted out.
 		*/
 		IntType next() {
-			const auto result = value_ & 1;
-			value_ = (value_ >> 1) ^ (result * polynomial);
+			const auto result = IntType(value_ & 1);
+			value_ = IntType((value_ >> 1) ^ (result * polynomial));
 			return result;
 		}
 
@@ -76,6 +78,8 @@ template <typename IntType = uint64_t, IntType polynomial = LSFRPolynomial<IntTy
 		IntType value_ = 0;
 };
 
+template <uint64_t polynomial> class LFSRv: public LFSR<typename MinIntTypeValue<polynomial>::type, polynomial> {};
+
 }
 
 #endif /* LFSR_h */

Numeric/Sizes.hpp

@@ -10,6 +10,7 @@
 #define Sizes_h
 
 #include <limits>
+#include <type_traits>
 
 /*!
 	Maps to the smallest integral type that can contain max_value, from the following options:

OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal Kiosk.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1200"
+   LastUpgradeVersion = "1240"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
@@ -56,6 +56,18 @@
             argument = "/Users/thomasharte/Downloads/test-dsk-for-rw-and-50-60-hz/TEST-RW-60Hz.DSK"
             isEnabled = "NO">
          </CommandLineArgument>
+         <CommandLineArgument
+            argument = "&quot;/Users/thomasharte/Desktop/Soft/Apple II/WOZs/Prince of Persia side A.woz&quot;"
+            isEnabled = "NO">
+         </CommandLineArgument>
+         <CommandLineArgument
+            argument = "--rompath=~/ROMs"
+            isEnabled = "NO">
+         </CommandLineArgument>
+         <CommandLineArgument
+            argument = "--has-disk-drive"
+            isEnabled = "NO">
+         </CommandLineArgument>
          <CommandLineArgument
             argument = "&quot;/Users/thomasharte/Library/Mobile Documents/com~apple~CloudDocs/Desktop/Soft/Macintosh/MusicWorks 0.42.image&quot;"
             isEnabled = "NO">
@@ -70,11 +82,15 @@
          </CommandLineArgument>
          <CommandLineArgument
             argument = "--volume=0.001"
-            isEnabled = "NO">
+            isEnabled = "YES">
          </CommandLineArgument>
          <CommandLineArgument
-            argument = "--new=amstradcpc"
-            isEnabled = "NO">
+            argument = "--new=enterprise"
+            isEnabled = "YES">
+         </CommandLineArgument>
+         <CommandLineArgument
+            argument = "--basic-version=any"
+            isEnabled = "YES">
          </CommandLineArgument>
          <CommandLineArgument
             argument = "&quot;/Users/thomasharte/Library/Mobile Documents/com~apple~CloudDocs/Desktop/Soft/ColecoVision/Galaxian (1983)(Atari).col&quot;"
@@ -106,14 +122,22 @@
          </CommandLineArgument>
          <CommandLineArgument
             argument = "--rompath=/Users/thomasharte/Projects/CLK/ROMImages"
-            isEnabled = "NO">
-         </CommandLineArgument>
-         <CommandLineArgument
-            argument = "--help"
             isEnabled = "YES">
          </CommandLineArgument>
          <CommandLineArgument
-            argument = "--model=cpc6128"
+            argument = "--help"
+            isEnabled = "NO">
+         </CommandLineArgument>
+         <CommandLineArgument
+            argument = "--model=mac512k"
+            isEnabled = "NO">
+         </CommandLineArgument>
+         <CommandLineArgument
+            argument = "--new=macintosh"
+            isEnabled = "NO">
+         </CommandLineArgument>
+         <CommandLineArgument
+            argument = "--use-square-pixels"
             isEnabled = "NO">
          </CommandLineArgument>
       </CommandLineArguments>

OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1200"
+   LastUpgradeVersion = "1240"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
@@ -73,6 +73,7 @@
       debugDocumentVersioning = "YES"
       migratedStopOnEveryIssue = "YES"
       debugServiceExtension = "internal"
+      enableGPUShaderValidationMode = "2"
       allowLocationSimulation = "NO">
       <BuildableProductRunnable
          runnableDebuggingMode = "0">

OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock SignalTests.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1200"
+   LastUpgradeVersion = "1240"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"

OSBindings/Mac/Clock Signal/AppDelegate.swift

@@ -11,12 +11,24 @@ import Cocoa
 @NSApplicationMain
 class AppDelegate: NSObject, NSApplicationDelegate {
 
-	func applicationDidFinishLaunching(_ aNotification: Notification) {
+	private var failedMetalCheck = false
+	func applicationDidFinishLaunching(_ notification: Notification) {
 		// Insert code here to initialize your application.
-	}
 
-	func applicationWillTerminate(_ aNotification: Notification) {
-		// Insert code here to tear down your application.
+		// Check for at least one Metal-capable GPU; this check
+		// will become unnecessary if/when the minimum OS version
+		// that this project supports reascends to 10.14.
+		if (MTLCopyAllDevices().count == 0) {
+			self.failedMetalCheck = true
+
+			let alert = NSAlert()
+			alert.messageText = "This application requires a Metal-capable GPU"
+			alert.addButton(withTitle: "Exit")
+			alert.runModal()
+
+			let application = notification.object as! NSApplication
+			application.terminate(self)
+		}
 	}
 
 	private var hasShownOpenDocument = false

OSBindings/Mac/Clock Signal/Base.lproj/AppleIIOptions.xib

@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="14460.31" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="18122" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
     <dependencies>
         <deployment identifier="macosx"/>
-        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="14460.31"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="18122"/>
         <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
     </dependencies>
     <objects>
@@ -13,17 +13,27 @@
         </customObject>
         <customObject id="-1" userLabel="First Responder" customClass="FirstResponder"/>
         <customObject id="-3" userLabel="Application" customClass="NSObject"/>
-        <window title="Options" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" hidesOnDeactivate="YES" releasedWhenClosed="NO" visibleAtLaunch="NO" frameAutosaveName="" animationBehavior="default" id="ZW7-Bw-4RP" customClass="MachinePanel" customModule="Clock_Signal" customModuleProvider="target">
+        <window title="Options" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" hidesOnDeactivate="YES" releasedWhenClosed="NO" visibleAtLaunch="NO" frameAutosaveName="" animationBehavior="default" id="ZW7-Bw-4RP" customClass="AppleIIOptionsPanel" customModule="Clock_Signal" customModuleProvider="target">
             <windowStyleMask key="styleMask" titled="YES" closable="YES" utility="YES" nonactivatingPanel="YES" HUD="YES"/>
             <windowPositionMask key="initialPositionMask" leftStrut="YES" rightStrut="YES" topStrut="YES" bottomStrut="YES"/>
-            <rect key="contentRect" x="80" y="150" width="200" height="61"/>
-            <rect key="screenRect" x="0.0" y="0.0" width="1440" height="900"/>
+            <rect key="contentRect" x="80" y="150" width="200" height="159"/>
+            <rect key="screenRect" x="0.0" y="0.0" width="2560" height="1440"/>
             <view key="contentView" id="tpZ-0B-QQu">
-                <rect key="frame" x="0.0" y="0.0" width="200" height="61"/>
+                <rect key="frame" x="0.0" y="0.0" width="200" height="84"/>
                 <autoresizingMask key="autoresizingMask"/>
                 <subviews>
+                    <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="kDb-7g-cVx">
+                        <rect key="frame" x="18" y="47" width="162" height="18"/>
+                        <buttonCell key="cell" type="check" title="Use Square Pixels" bezelStyle="regularSquare" imagePosition="left" state="on" inset="2" id="h9q-Wb-em8">
+                            <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
+                            <font key="font" metaFont="system"/>
+                        </buttonCell>
+                        <connections>
+                            <action selector="optionDidChange:" target="ZW7-Bw-4RP" id="pNS-aK-0no"/>
+                        </connections>
+                    </button>
                     <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="ex3-VM-58z">
-                        <rect key="frame" x="18" y="17" width="165" height="25"/>
+                        <rect key="frame" x="17" y="16" width="167" height="25"/>
                         <popUpButtonCell key="cell" type="push" title="Colour" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" tag="1" imageScaling="proportionallyDown" inset="2" selectedItem="gOu-dv-tre" id="u3N-Je-c2L">
                             <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                             <font key="font" metaFont="menu"/>
@@ -40,16 +50,20 @@
                     </popUpButton>
                 </subviews>
                 <constraints>
-                    <constraint firstAttribute="bottom" secondItem="ex3-VM-58z" secondAttribute="bottom" constant="20" id="4ZS-q5-TJL"/>
+                    <constraint firstAttribute="bottom" secondItem="ex3-VM-58z" secondAttribute="bottom" constant="20" symbolic="YES" id="4ZS-q5-TJL"/>
                     <constraint firstItem="ex3-VM-58z" firstAttribute="leading" secondItem="tpZ-0B-QQu" secondAttribute="leading" constant="20" id="8Pj-Ns-TrJ"/>
+                    <constraint firstAttribute="trailing" secondItem="kDb-7g-cVx" secondAttribute="trailing" constant="20" symbolic="YES" id="KHa-of-eY7"/>
+                    <constraint firstItem="kDb-7g-cVx" firstAttribute="leading" secondItem="tpZ-0B-QQu" secondAttribute="leading" constant="20" symbolic="YES" id="OcZ-Xa-394"/>
                     <constraint firstAttribute="trailing" secondItem="ex3-VM-58z" secondAttribute="trailing" constant="20" id="QWA-lY-ugz"/>
-                    <constraint firstItem="ex3-VM-58z" firstAttribute="top" secondItem="tpZ-0B-QQu" secondAttribute="top" constant="20" id="szw-WO-3tS"/>
+                    <constraint firstItem="ex3-VM-58z" firstAttribute="top" secondItem="kDb-7g-cVx" secondAttribute="bottom" constant="8" id="jDW-N8-c4V"/>
+                    <constraint firstItem="kDb-7g-cVx" firstAttribute="top" secondItem="tpZ-0B-QQu" secondAttribute="top" constant="20" symbolic="YES" id="wdj-PF-zxO"/>
                 </constraints>
             </view>
             <connections>
                 <outlet property="displayTypeButton" destination="ex3-VM-58z" id="lmZ-aN-lcj"/>
+                <outlet property="squarePixelButton" destination="kDb-7g-cVx" id="zbx-o8-7yC"/>
             </connections>
-            <point key="canvasLocation" x="-161" y="38.5"/>
+            <point key="canvasLocation" x="-161" y="104.5"/>
         </window>
     </objects>
 </document>

OSBindings/Mac/Clock Signal/Base.lproj/Atari2600Options.xib

@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="14113" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="18122" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
     <dependencies>
         <deployment identifier="macosx"/>
-        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="14113"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="18122"/>
         <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
     </dependencies>
     <objects>
@@ -13,17 +13,17 @@
         </customObject>
         <customObject id="-1" userLabel="First Responder" customClass="FirstResponder"/>
         <customObject id="-3" userLabel="Application" customClass="NSObject"/>
-        <window title="Options" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" hidesOnDeactivate="YES" oneShot="NO" releasedWhenClosed="NO" showsToolbarButton="NO" visibleAtLaunch="NO" frameAutosaveName="" animationBehavior="default" id="gsl-7V-TTU" customClass="Atari2600OptionsPanel" customModule="Clock_Signal" customModuleProvider="target">
+        <window title="Options" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" hidesOnDeactivate="YES" releasedWhenClosed="NO" visibleAtLaunch="NO" frameAutosaveName="" animationBehavior="default" id="gsl-7V-TTU" customClass="Atari2600OptionsPanel" customModule="Clock_Signal" customModuleProvider="target">
             <windowStyleMask key="styleMask" titled="YES" closable="YES" utility="YES" nonactivatingPanel="YES" HUD="YES"/>
             <windowPositionMask key="initialPositionMask" leftStrut="YES" rightStrut="YES" topStrut="YES" bottomStrut="YES"/>
             <rect key="contentRect" x="80" y="150" width="200" height="121"/>
-            <rect key="screenRect" x="0.0" y="0.0" width="1440" height="900"/>
+            <rect key="screenRect" x="0.0" y="0.0" width="2560" height="1440"/>
             <view key="contentView" id="aQh-Pm-DEo">
                 <rect key="frame" x="0.0" y="0.0" width="200" height="121"/>
                 <autoresizingMask key="autoresizingMask"/>
                 <subviews>
                     <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="rQO-uD-fwn">
-                        <rect key="frame" x="14" y="73" width="86" height="32"/>
+                        <rect key="frame" x="13" y="74" width="88" height="32"/>
                         <buttonCell key="cell" type="push" title="Reset" bezelStyle="rounded" alignment="center" borderStyle="border" imageScaling="proportionallyDown" inset="2" id="l3H-0m-aK0">
                             <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
                             <font key="font" metaFont="system"/>
@@ -33,7 +33,7 @@
                         </connections>
                     </button>
                     <button translatesAutoresizingMaskIntoConstraints="NO" id="3qw-C1-NYW">
-                        <rect key="frame" x="18" y="58" width="164" height="18"/>
+                        <rect key="frame" x="18" y="58" width="162" height="18"/>
                         <buttonCell key="cell" type="check" title="Black and White" bezelStyle="regularSquare" imagePosition="left" inset="2" id="UP7-mf-IKo">
                             <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
                             <font key="font" metaFont="system"/>
@@ -43,7 +43,7 @@
                         </connections>
                     </button>
                     <button translatesAutoresizingMaskIntoConstraints="NO" id="Xbc-cw-Sc2">
-                        <rect key="frame" x="18" y="38" width="164" height="18"/>
+                        <rect key="frame" x="18" y="36" width="162" height="18"/>
                         <buttonCell key="cell" type="check" title="Left Player Difficulty" bezelStyle="regularSquare" imagePosition="left" inset="2" id="wlJ-8s-PEh">
                             <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
                             <font key="font" metaFont="system"/>
@@ -53,7 +53,7 @@
                         </connections>
                     </button>
                     <button translatesAutoresizingMaskIntoConstraints="NO" id="kPV-Tm-TTc">
-                        <rect key="frame" x="18" y="18" width="164" height="18"/>
+                        <rect key="frame" x="18" y="14" width="162" height="18"/>
                         <buttonCell key="cell" type="check" title="Right Player Difficulty" bezelStyle="regularSquare" imagePosition="left" inset="2" id="F05-cA-66S">
                             <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
                             <font key="font" metaFont="system"/>
@@ -63,7 +63,7 @@
                         </connections>
                     </button>
                     <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="nt7-8K-xY9">
-                        <rect key="frame" x="100" y="73" width="86" height="32"/>
+                        <rect key="frame" x="99" y="74" width="88" height="32"/>
                         <buttonCell key="cell" type="push" title="Select" bezelStyle="rounded" alignment="center" borderStyle="border" imageScaling="proportionallyDown" inset="2" id="8Na-Z1-EXS">
                             <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
                             <font key="font" metaFont="system"/>

OSBindings/Mac/Clock Signal/Documents/AppleIIOptionsPanel.swift

@@ -0,0 +1,37 @@
+//
+//  AppleIIOptionsPanel.swift
+//  Clock Signal
+//
+//  Created by Thomas Harte on 07/06/2021.
+//  Copyright 2021 Thomas Harte. All rights reserved.
+//
+
+class AppleIIOptionsPanel: MachinePanel {
+	var appleII: CSAppleII! {
+		get {
+			return self.machine.appleII
+		}
+	}
+	var squarePixelsUserDefaultsKey: String {
+		return prefixedUserDefaultsKey("useSquarePixels")
+	}
+
+	@IBOutlet var squarePixelButton: NSButton!
+
+	@IBAction func optionDidChange(_ sender: AnyObject!) {
+		let useSquarePixels = squarePixelButton.state == .on
+		appleII.useSquarePixels = useSquarePixels
+
+		let standardUserDefaults = UserDefaults.standard
+		standardUserDefaults.set(useSquarePixels, forKey: squarePixelsUserDefaultsKey)
+	}
+
+	override func establishStoredOptions() {
+		super.establishStoredOptions()
+
+		let standardUserDefaults = UserDefaults.standard
+		let useSquarePixels = standardUserDefaults.bool(forKey: squarePixelsUserDefaultsKey)
+		appleII.useSquarePixels = useSquarePixels
+		squarePixelButton.state = useSquarePixels ? .on : .off
+	}
+}

OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift

@@ -87,6 +87,14 @@ class MachineDocument:
 		}
 	}
 
+	private func dismissPanels() {
+		activityPanel?.setIsVisible(false)
+		activityPanel = nil
+
+		optionsPanel?.setIsVisible(false)
+		optionsPanel = nil
+	}
+
 	override func close() {
 		// Close any dangling sheets.
 		//
@@ -105,11 +113,7 @@ class MachineDocument:
 		machine?.stop()
 
 		// Dismiss panels.
-		activityPanel?.setIsVisible(false)
-		activityPanel = nil
-
-		optionsPanel?.setIsVisible(false)
-		optionsPanel = nil
+		dismissPanels()
 
 		// End the update cycle.
 		actionLock.lock()
@@ -133,23 +137,27 @@ class MachineDocument:
 		volumeSlider.floatValue = userDefaultsVolume()
 	}
 
-	private var missingROMs: [CSMissingROM] = []
+	private var missingROMs: String = ""
 	func configureAs(_ analysis: CSStaticAnalyser) {
 		self.machineDescription = analysis
 
-		let missingROMs = NSMutableArray()
+		actionLock.lock()
+		drawLock.lock()
+
+		let missingROMs = NSMutableString()
 		if let machine = CSMachine(analyser: analysis, missingROMs: missingROMs) {
+			setRomRequesterIsVisible(false)
+
 			self.machine = machine
-			setupActivityDisplay()
 			machine.setVolume(userDefaultsVolume())
 			setupMachineOutput()
 		} else {
-			// Store the selected machine and list of missing ROMs, and
-			// show the missing ROMs dialogue.
-			self.missingROMs = missingROMs.map({$0 as! CSMissingROM})
-
+			self.missingROMs = missingROMs as String
 			requestRoms()
 		}
+
+		actionLock.unlock()
+		drawLock.unlock()
 	}
 
 	enum InteractionMode {
@@ -200,6 +208,9 @@ class MachineDocument:
 			let aspectRatio = self.aspectRatio()
 			machine.setView(scanTargetView, aspectRatio: Float(aspectRatio.width / aspectRatio.height))
 
+			// Get rid of all existing accessory panels.
+			dismissPanels()
+
 			// Attach an options panel if one is available.
 			if let optionsPanelNibName = self.machineDescription?.optionsPanelNibName {
 				Bundle.main.loadNibNamed(optionsPanelNibName, owner: self, topLevelObjects: nil)
@@ -208,11 +219,10 @@ class MachineDocument:
 				showOptions(self)
 			}
 
-			machine.delegate = self
+			// Create and populate an activity display if required.
+			setupActivityDisplay()
 
-			// Callbacks from the OpenGL may come on a different thread, immediately following the .delegate set;
-			// hence the full setup of the best-effort updater prior to setting self as a delegate.
-//			scanTargetView.delegate = self
+			machine.delegate = self
 			scanTargetView.responderDelegate = self
 
 			// If this machine has a mouse, enable mouse capture; also indicate whether usurption
@@ -252,7 +262,7 @@ class MachineDocument:
 		let isStereo = self.machine.isStereo
 		if selectedSamplingRate > 0 {
 			// [Re]create the audio queue only if necessary.
-			if self.audioQueue == nil || self.audioQueue.samplingRate != selectedSamplingRate {
+			if self.audioQueue == nil || self.audioQueue.samplingRate != selectedSamplingRate || self.audioQueue != self.machine.audioQueue {
 				self.machine.audioQueue = nil
 				self.audioQueue = CSAudioQueue(samplingRate: Float64(selectedSamplingRate), isStereo:isStereo)
 				self.audioQueue.delegate = self
@@ -280,8 +290,7 @@ class MachineDocument:
 
 	/// Delegate message to receive drag and drop files.
 	final func scanTargetView(_ view: CSScanTargetView, didReceiveFileAt URL: URL) {
-		let mediaSet = CSMediaSet(fileAt: URL)
-		mediaSet.apply(to: self.machine)
+		insertFile(URL)
 	}
 
 	/// Action for the insert menu command; displays an NSOpenPanel and then segues into the same process
@@ -292,13 +301,30 @@ class MachineDocument:
 		openPanel.beginSheetModal(for: self.windowControllers[0].window!) { (response) in
 			if response == .OK {
 				for url in openPanel.urls {
-					let mediaSet = CSMediaSet(fileAt: url)
-					mediaSet.apply(to: self.machine)
+					self.insertFile(url)
 				}
 			}
 		}
 	}
 
+	private func insertFile(_ URL: URL) {
+		// Try to insert media.
+		let mediaSet = CSMediaSet(fileAt: URL)
+		if !mediaSet.empty {
+			mediaSet.apply(to: self.machine)
+			return
+		}
+
+		// Failing that see whether a new machine is required.
+		// TODO.
+		if let newMachine = CSStaticAnalyser(fileAt: URL) {
+			machine?.stop()
+			self.interactionMode = .notStarted
+			self.scanTargetView.willChangeScanTargetOwner()
+			configureAs(newMachine)
+		}
+	}
+
 	// MARK: - Input Management.
 
 	/// Upon a resign key, immediately releases all ongoing input mechanisms — any currently pressed keys,
@@ -387,23 +413,42 @@ class MachineDocument:
 	@IBOutlet var romReceiverErrorField: NSTextField?
 	@IBOutlet var romReceiverView: CSROMReceiverView?
 	private var romRequestBaseText = ""
+
+	private func setRomRequesterIsVisible(_ visible : Bool) {
+		if !visible && self.romRequesterPanel == nil {
+			return;
+		}
+
+		if self.romRequesterPanel!.isVisible == visible {
+			return
+		}
+
+		if visible {
+			self.windowControllers[0].window?.beginSheet(self.romRequesterPanel!, completionHandler: nil)
+		} else {
+			self.windowControllers[0].window?.endSheet(self.romRequesterPanel!)
+		}
+	}
+
 	func requestRoms() {
 		// Don't act yet if there's no window controller yet.
 		if self.windowControllers.count == 0 {
 			return
 		}
 
-		// Load the ROM requester dialogue.
-		Bundle.main.loadNibNamed("ROMRequester", owner: self, topLevelObjects: nil)
-		self.romReceiverView!.delegate = self
-		self.romRequestBaseText = romRequesterText!.stringValue
-		romReceiverErrorField?.alphaValue = 0.0
+		// Load the ROM requester dialogue if it's not already loaded.
+		if self.romRequesterPanel == nil {
+			Bundle.main.loadNibNamed("ROMRequester", owner: self, topLevelObjects: nil)
+			self.romReceiverView!.delegate = self
+			self.romRequestBaseText = romRequesterText!.stringValue
+			romReceiverErrorField?.alphaValue = 0.0
+		}
 
 		// Populate the current absentee list.
 		populateMissingRomList()
 
 		// Show the thing.
-		self.windowControllers[0].window?.beginSheet(self.romRequesterPanel!, completionHandler: nil)
+		setRomRequesterIsVisible(true)
 	}
 
 	@IBAction func cancelRequestROMs(_ sender: NSButton?) {
@@ -411,89 +456,17 @@ class MachineDocument:
 	}
 
 	func populateMissingRomList() {
-		// Fill in the missing details; first build a list of all the individual
-		// line items.
-		var requestLines: [String] = []
-		for missingROM in self.missingROMs {
-			if let descriptiveName = missingROM.descriptiveName {
-				requestLines.append("• " + descriptiveName)
-			} else {
-				requestLines.append("• " + missingROM.fileName)
-			}
-		}
-
-		// Suffix everything up to the penultimate line with a semicolon;
-		// the penultimate line with a semicolon and a conjunctive; the final
-		// line with a full stop.
-		for x in 0 ..< requestLines.count {
-			if x < requestLines.count - 2 {
-				requestLines[x].append(";")
-			} else if x < requestLines.count - 1 {
-				requestLines[x].append("; and")
-			} else {
-				requestLines[x].append(".")
-			}
-		}
-		romRequesterText!.stringValue = self.romRequestBaseText + requestLines.joined(separator: "\n")
+		romRequesterText!.stringValue = self.romRequestBaseText + self.missingROMs
 	}
 
 	func romReceiverView(_ view: CSROMReceiverView, didReceiveFileAt URL: URL) {
 		// Test whether the file identified matches any of the currently missing ROMs.
 		// If so then remove that ROM from the missing list and update the request screen.
 		// If no ROMs are still missing, start the machine.
-		do {
-			let fileData = try Data(contentsOf: URL)
-			var didInstallRom = false
-
-			// Try to match by size first, CRC second. Accept that some ROMs may have
-			// some additional appended data. Arbitrarily allow them to be up to 10kb
-			// too large.
-			var index = 0
-			for missingROM in self.missingROMs {
-				if fileData.count >= missingROM.size && fileData.count < missingROM.size + 10*1024 {
-					// Trim to size.
-					let trimmedData = fileData[0 ..< missingROM.size]
-
-					// Get CRC.
-					if missingROM.crc32s.contains( (trimmedData as NSData).crc32 ) {
-						// This ROM matches; copy it into the application library,
-						// strike it from the missing ROM list and decide how to
-						// proceed.
-						let fileManager = FileManager.default
-						let targetPath = fileManager.urls(for: .applicationSupportDirectory, in: .userDomainMask)[0]
-							.appendingPathComponent("ROMImages")
-							.appendingPathComponent(missingROM.machineName)
-						let targetFile = targetPath
-							.appendingPathComponent(missingROM.fileName)
-
-						do {
-							try fileManager.createDirectory(atPath: targetPath.path, withIntermediateDirectories: true, attributes: nil)
-							try trimmedData.write(to: targetFile)
-						} catch let error {
-							showRomReceiverError(error: "Couldn't write to application support directory: \(error)")
-						}
-
-						self.missingROMs.remove(at: index)
-						didInstallRom = true
-						break
-					}
-				}
-
-				index = index + 1
-			}
-
-			if didInstallRom {
-				if self.missingROMs.count == 0 {
-					self.windowControllers[0].window?.endSheet(self.romRequesterPanel!)
-					configureAs(self.machineDescription!)
-				} else {
-					populateMissingRomList()
-				}
-			} else {
-				showRomReceiverError(error: "Didn't recognise contents of \(URL.lastPathComponent)")
-			}
-		} catch let error {
-			showRomReceiverError(error: "Couldn't read file at \(URL.absoluteString): \(error)")
+		if CSMachine.attemptInstallROM(URL) {
+			configureAs(self.machineDescription!)
+		} else {
+			showRomReceiverError(error: "Didn't recognise contents of \(URL.lastPathComponent)")
 		}
 	}
 

OSBindings/Mac/Clock Signal/Info.plist

@@ -592,6 +592,66 @@
 			<key>NSDocumentClass</key>
 			<string>$(PRODUCT_MODULE_NAME).MachineDocument</string>
 		</dict>
+		<dict>
+			<key>CFBundleTypeExtensions</key>
+			<array>
+				<string>sna</string>
+			</array>
+			<key>CFBundleTypeName</key>
+			<string>ZX Spectrum SNA snapshot</string>
+			<key>CFBundleTypeOSTypes</key>
+			<array>
+				<string>????</string>
+			</array>
+			<key>CFBundleTypeRole</key>
+			<string>Viewer</string>
+			<key>LSHandlerRank</key>
+			<string>Owner</string>
+			<key>LSTypeIsPackage</key>
+			<false/>
+			<key>NSDocumentClass</key>
+			<string>$(PRODUCT_MODULE_NAME).MachineDocument</string>
+		</dict>
+		<dict>
+			<key>CFBundleTypeExtensions</key>
+			<array>
+				<string>z80</string>
+			</array>
+			<key>CFBundleTypeName</key>
+			<string>ZX Spectrum Z80 snapshot</string>
+			<key>CFBundleTypeOSTypes</key>
+			<array>
+				<string>????</string>
+			</array>
+			<key>CFBundleTypeRole</key>
+			<string>Viewer</string>
+			<key>LSHandlerRank</key>
+			<string>Owner</string>
+			<key>LSTypeIsPackage</key>
+			<false/>
+			<key>NSDocumentClass</key>
+			<string>$(PRODUCT_MODULE_NAME).MachineDocument</string>
+		</dict>
+		<dict>
+			<key>CFBundleTypeExtensions</key>
+			<array>
+				<string>szx</string>
+			</array>
+			<key>CFBundleTypeName</key>
+			<string>ZX Spectrum SZX snapshot</string>
+			<key>CFBundleTypeOSTypes</key>
+			<array>
+				<string>????</string>
+			</array>
+			<key>CFBundleTypeRole</key>
+			<string>Viewer</string>
+			<key>LSHandlerRank</key>
+			<string>Owner</string>
+			<key>LSTypeIsPackage</key>
+			<false/>
+			<key>NSDocumentClass</key>
+			<string>$(PRODUCT_MODULE_NAME).MachineDocument</string>
+		</dict>
 	</array>
 	<key>CFBundleExecutable</key>
 	<string>$(EXECUTABLE_NAME)</string>

OSBindings/Mac/Clock Signal/Joystick Manager/CSJoystickManager.m

@@ -368,7 +368,7 @@ API_AVAILABLE(macos(11.0))
 	return self;
 }
 
--(void)update {
+- (void)update {
 	// Update buttons.
 	for(CSGCJoystickButton *button in _buttons) {
 		// This assumes that the values provided by GCDeviceButtonInput are
@@ -379,7 +379,11 @@ API_AVAILABLE(macos(11.0))
 		float val = axis.axis.value;
 		val += 1;
 		val /= 2;
-		axis.position = val;
+		if(axis.type == CSJoystickAxisTypeY) {
+			axis.position = 1 - val;
+		} else {
+			axis.position = val;
+		}
 	}
 	for(CSGCJoystickHat *hat in _hats) {
 		// This assumes that the values provided by GCDeviceDirectionPad are

OSBindings/Mac/Clock Signal/Machine/CSMachine.h

@@ -33,20 +33,15 @@ typedef NS_ENUM(NSInteger, CSMachineKeyboardInputMode) {
 	CSMachineKeyboardInputModeJoystick,
 };
 
-@interface CSMissingROM: NSObject
-@property (nonatomic, readonly, nonnull) NSString *machineName;
-@property (nonatomic, readonly, nonnull) NSString *fileName;
-@property (nonatomic, readonly, nullable) NSString *descriptiveName;
-@property (nonatomic, readonly) NSUInteger size;
-@property (nonatomic, readonly, nonnull) NSArray<NSNumber *> *crc32s;
-@end
-
 // Deliberately low; to ensure CSMachine has been declared as an @class already.
 #import "CSAtari2600.h"
 #import "CSZX8081.h"
+#import "CSAppleII.h"
 
 @interface CSMachine : NSObject
 
++ (BOOL)attemptInstallROM:(nonnull NSURL *)url;
+
 - (nonnull instancetype)init NS_UNAVAILABLE;
 
 /*!
@@ -56,7 +51,7 @@ typedef NS_ENUM(NSInteger, CSMachineKeyboardInputMode) {
 	@param missingROMs An array that is filled with a list of ROMs that the machine requested but which
 		were not found; populated only if this `init` has failed.
 */
-- (nullable instancetype)initWithAnalyser:(nonnull CSStaticAnalyser *)result missingROMs:(nullable inout NSMutableArray<CSMissingROM *> *)missingROMs NS_DESIGNATED_INITIALIZER;
+- (nullable instancetype)initWithAnalyser:(nonnull CSStaticAnalyser *)result missingROMs:(nullable inout NSMutableString *)missingROMs NS_DESIGNATED_INITIALIZER;
 
 - (float)idealSamplingRateFromRange:(NSRange)range;
 @property (readonly, getter=isStereo) BOOL stereo;
@@ -109,5 +104,6 @@ typedef NS_ENUM(NSInteger, CSMachineKeyboardInputMode) {
 // Special-case accessors; undefined behaviour if accessed for a machine not of the corresponding type.
 @property (nonatomic, readonly, nullable) CSAtari2600 *atari2600;
 @property (nonatomic, readonly, nullable) CSZX8081 *zx8081;
+@property (nonatomic, readonly, nullable) CSAppleII *appleII;
 
 @end

OSBindings/Mac/Clock Signal/Machine/CSMachine.mm

@@ -31,6 +31,8 @@
 
 #include <atomic>
 #include <bitset>
+#include <codecvt>
+#include <locale>
 
 @interface CSMachine() <CSScanTargetViewDisplayLinkDelegate>
 - (void)speaker:(Outputs::Speaker::Speaker *)speaker didCompleteSamples:(const int16_t *)samples length:(int)length;
@@ -74,28 +76,6 @@ struct ActivityObserver: public Activity::Observer {
 	__unsafe_unretained CSMachine *machine;
 };
 
-@interface CSMissingROM (/*Mutability*/)
-@property (nonatomic, nonnull, copy) NSString *machineName;
-@property (nonatomic, nonnull, copy) NSString *fileName;
-@property (nonatomic, nullable, copy) NSString *descriptiveName;
-@property (nonatomic, readwrite) NSUInteger size;
-@property (nonatomic, copy) NSArray<NSNumber *> *crc32s;
-@end
-
-@implementation CSMissingROM
-
-@synthesize machineName=_machineName;
-@synthesize fileName=_fileName;
-@synthesize descriptiveName=_descriptiveName;
-@synthesize size=_size;
-@synthesize crc32s=_crc32s;
-
-- (NSString *)description {
-	return [NSString stringWithFormat:@"%@/%@, %lu bytes, CRCs: %@", _fileName, _descriptiveName, (unsigned long)_size, _crc32s];
-}
-
-@end
-
 @implementation CSMachine {
 	SpeakerDelegate _speakerDelegate;
 	ActivityObserver _activityObserver;
@@ -126,35 +106,18 @@ struct ActivityObserver: public Activity::Observer {
 	NSMutableArray<dispatch_block_t> *_inputEvents;
 }
 
-- (instancetype)initWithAnalyser:(CSStaticAnalyser *)result missingROMs:(inout NSMutableArray<CSMissingROM *> *)missingROMs {
+- (instancetype)initWithAnalyser:(CSStaticAnalyser *)result missingROMs:(inout NSMutableString *)missingROMs {
 	self = [super init];
 	if(self) {
 		_analyser = result;
 
 		Machine::Error error;
-		std::vector<ROMMachine::ROM> missing_roms;
+		ROM::Request missing_roms;
 		_machine.reset(Machine::MachineForTargets(_analyser.targets, CSROMFetcher(&missing_roms), error));
 		if(!_machine) {
-			for(const auto &missing_rom : missing_roms) {
-				CSMissingROM *rom = [[CSMissingROM alloc] init];
-
-				// Copy/convert the primitive fields.
-				rom.machineName = @(missing_rom.machine_name.c_str());
-				rom.fileName = @(missing_rom.file_name.c_str());
-				rom.descriptiveName = missing_rom.descriptive_name.empty() ? nil : @(missing_rom.descriptive_name.c_str());
-				rom.size = missing_rom.size;
-
-				// Convert the CRC list.
-				NSMutableArray<NSNumber *> *crc32s = [[NSMutableArray alloc] initWithCapacity:missing_rom.crc32s.size()];
-				for(const auto &crc : missing_rom.crc32s) {
-					[crc32s addObject:@(crc)];
-				}
-				rom.crc32s = crc32s;
-
-				// Add to the missing list.
-				[missingROMs addObject:rom];
-			}
-
+			std::wstring_convert<std::codecvt_utf8<wchar_t>> wstring_converter;
+			const std::wstring description = missing_roms.description(0, L'•');
+			[missingROMs appendString:[NSString stringWithUTF8String:wstring_converter.to_bytes(description).c_str()]];
 			return nil;
 		}
 
@@ -614,6 +577,10 @@ struct ActivityObserver: public Activity::Observer {
 	return [[CSZX8081 alloc] initWithZX8081:_machine->raw_pointer() owner:self];
 }
 
+- (CSAppleII *)appleII {
+	return [[CSAppleII alloc] initWithAppleII:_machine->raw_pointer() owner:self];
+}
+
 #pragma mark - Input device queries
 
 - (BOOL)hasJoystick {
@@ -783,4 +750,8 @@ struct ActivityObserver: public Activity::Observer {
 	_timer = nil;
 }
 
++ (BOOL)attemptInstallROM:(NSURL *)url {
+	return CSInstallROM(url);
+}
+
 @end

OSBindings/Mac/Clock Signal/Machine/CSROMFetcher.hpp

@@ -8,4 +8,5 @@
 
 #include "ROMMachine.hpp"
 
-ROMMachine::ROMFetcher CSROMFetcher(std::vector<ROMMachine::ROM> *missing_roms = nullptr);
+ROMMachine::ROMFetcher CSROMFetcher(ROM::Request *missing = nullptr);
+BOOL CSInstallROM(NSURL *);

OSBindings/Mac/Clock Signal/Machine/CSROMFetcher.mm

@@ -11,47 +11,96 @@
 
 #import "NSBundle+DataResource.h"
 #import "NSData+StdVector.h"
+#import "NSData+CRC32.h"
 
 #include <string>
 
-ROMMachine::ROMFetcher CSROMFetcher(std::vector<ROMMachine::ROM> *missing_roms) {
-	return [missing_roms] (const std::vector<ROMMachine::ROM> &roms) -> std::vector<std::unique_ptr<std::vector<std::uint8_t>>> {
-		NSArray<NSURL *> *const supportURLs = [[NSFileManager defaultManager] URLsForDirectory:NSApplicationSupportDirectory inDomains:NSUserDomainMask];
+namespace {
 
-		std::vector<std::unique_ptr<std::vector<std::uint8_t>>> results;
-		for(const auto &rom: roms) {
-			NSData *fileData;
-			NSString *const subdirectory = [@"ROMImages/" stringByAppendingString:[NSString stringWithUTF8String:rom.machine_name.c_str()]];
+NSString *directoryFor(const ROM::Description &description) {
+	return [@"ROMImages/" stringByAppendingString:[NSString stringWithUTF8String:description.machine_name.c_str()]];
+}
 
-			// Check for this file first within the application support directories.
-			for(NSURL *supportURL in supportURLs) {
-				NSURL *const fullURL = [[supportURL URLByAppendingPathComponent:subdirectory]
-							URLByAppendingPathComponent:[NSString stringWithUTF8String:rom.file_name.c_str()]];
-				fileData = [NSData dataWithContentsOfURL:fullURL];
-				if(fileData) break;
+NSArray<NSURL *> *urlsFor(const ROM::Description &description, const std::string &file_name) {
+	NSMutableArray<NSURL *> *const urls = [[NSMutableArray alloc] init];
+	NSArray<NSURL *> *const supportURLs = [[NSFileManager defaultManager] URLsForDirectory:NSApplicationSupportDirectory inDomains:NSUserDomainMask];
+	NSString *const subdirectory = directoryFor(description);
+
+	for(NSURL *supportURL in supportURLs) {
+		[urls addObject:[[supportURL URLByAppendingPathComponent:subdirectory]
+								URLByAppendingPathComponent:[NSString stringWithUTF8String:file_name.c_str()]]];
+	}
+
+	return urls;
+}
+
+}
+
+BOOL CSInstallROM(NSURL *url) {
+	NSData *const data = [NSData dataWithContentsOfURL:url];
+	if(!data) return NO;
+
+	// Try for a direct CRC match.
+	std::optional<ROM::Description> target_description;
+	target_description = ROM::Description::from_crc(uint32_t(data.crc32.integerValue));
+
+	// See whether there's an acceptable trimming that creates a CRC match.
+	if(!target_description) {
+		const std::vector<ROM::Description> descriptions = ROM::all_descriptions();
+		for(const auto &description: descriptions) {
+			if(description.size > data.length) continue;
+
+			NSData *const trimmedData = [data subdataWithRange:NSMakeRange(0, description.size)];
+			if(description.crc32s.find(uint32_t(trimmedData.crc32.unsignedIntValue)) != description.crc32s.end()) {
+				target_description = description;
+				break;
 			}
+		}
+	}
 
-			// Failing that, check inside the application bundle.
-			if(!fileData) {
-				fileData = [[NSBundle mainBundle]
-					dataForResource:[NSString stringWithUTF8String:rom.file_name.c_str()]
-					withExtension:nil
-					subdirectory:subdirectory];
-			}
+	// If no destination was found, stop.
+	if(!target_description) {
+		return NO;
+	}
 
-			// Store an appropriate result, accumulating a list of the missing if requested.
-			if(!fileData) {
-				results.emplace_back(nullptr);
+	// Copy the data to its destination and report success.
+	NSURL *const targetURL = [urlsFor(*target_description, target_description->file_names[0]) firstObject];
+	[[NSFileManager defaultManager] createDirectoryAtPath:targetURL.URLByDeletingLastPathComponent.path withIntermediateDirectories:YES attributes:nil error:nil];
+	[data writeToURL:targetURL atomically:NO];
 
-				if(missing_roms) {
-					missing_roms->push_back(rom);
+	return YES;
+}
+
+ROMMachine::ROMFetcher CSROMFetcher(ROM::Request *missing) {
+	return [missing] (const ROM::Request &roms) -> ROM::Map {
+		ROM::Map results;
+		for(const auto &description: roms.all_descriptions()) {
+			for(const auto &file_name: description.file_names) {
+				NSData *fileData;
+
+				// Check for this file first within the application support directories.
+				for(NSURL *fileURL in urlsFor(description, file_name)) {
+					fileData = [NSData dataWithContentsOfURL:fileURL];
+					if(fileData) break;
+				}
+
+				// Failing that, check inside the application bundle.
+				if(!fileData) {
+					fileData = [[NSBundle mainBundle]
+						dataForResource:[NSString stringWithUTF8String:file_name.c_str()]
+						withExtension:nil
+						subdirectory:directoryFor(description)];
+				}
+
+				// Store an appropriate result.
+				if(fileData) {
+					results[description.name] = fileData.stdVector8;
 				}
 			}
-			else {
-				auto data = std::make_unique<std::vector<std::uint8_t>>();
-				*data = fileData.stdVector8;
-				results.emplace_back(std::move(data));
-			}
+		}
+
+		if(missing) {
+			*missing = roms.subtract(results);
 		}
 
 		return results;

OSBindings/Mac/Clock Signal/Machine/StaticAnalyser/CSStaticAnalyser.h

@@ -41,6 +41,30 @@ typedef NS_ENUM(NSInteger, CSMachineCPCModel) {
 	CSMachineCPCModel6128
 };
 
+typedef NS_ENUM(NSInteger, CSMachineEnterpriseModel) {
+	CSMachineEnterpriseModel64,
+	CSMachineEnterpriseModel128,
+	CSMachineEnterpriseModel256,
+};
+
+typedef NS_ENUM(NSInteger, CSMachineEnterpriseEXOS) {
+	CSMachineEnterpriseEXOSVersion21,
+	CSMachineEnterpriseEXOSVersion20,
+	CSMachineEnterpriseEXOSVersion10,
+};
+
+typedef NS_ENUM(NSInteger, CSMachineEnterpriseBASIC) {
+	CSMachineEnterpriseBASICVersion21,
+	CSMachineEnterpriseBASICVersion11,
+	CSMachineEnterpriseBASICVersion10,
+	CSMachineEnterpriseBASICNone,
+};
+
+typedef NS_ENUM(NSInteger, CSMachineEnterpriseDOS) {
+	CSMachineEnterpriseDOSEXDOS,
+	CSMachineEnterpriseDOSNone,
+};
+
 typedef NS_ENUM(NSInteger, CSMachineMacintoshModel) {
 	CSMachineMacintoshModel128k,
 	CSMachineMacintoshModel512k,
@@ -96,6 +120,7 @@ typedef int Kilobytes;
 - (instancetype)initWithAppleIIgsModel:(CSMachineAppleIIgsModel)model memorySize:(Kilobytes)memorySize;
 - (instancetype)initWithAtariSTModel:(CSMachineAtariSTModel)model;
 - (instancetype)initWithElectronDFS:(BOOL)dfs adfs:(BOOL)adfs ap6:(BOOL)ap6 sidewaysRAM:(BOOL)sidewaysRAM;
+- (instancetype)initWithEnterpriseModel:(CSMachineEnterpriseModel)model exosVersion:(CSMachineEnterpriseEXOS)exosVersion basicVersion:(CSMachineEnterpriseBASIC)basicVersion dos:(CSMachineEnterpriseDOS)dos;
 - (instancetype)initWithMacintoshModel:(CSMachineMacintoshModel)model;
 - (instancetype)initWithMSXRegion:(CSMachineMSXRegion)region hasDiskDrive:(BOOL)hasDiskDrive;
 - (instancetype)initWithOricModel:(CSMachineOricModel)model diskInterface:(CSMachineOricDiskInterface)diskInterface;
@@ -114,6 +139,8 @@ typedef int Kilobytes;
 - (instancetype)initWithFileAtURL:(NSURL *)url;
 - (void)applyToMachine:(CSMachine *)machine;
 
+@property(nonatomic, readonly) BOOL empty;
+
 @end
 
 NS_ASSUME_NONNULL_END

OSBindings/Mac/Clock Signal/Machine/StaticAnalyser/CSStaticAnalyser.mm

@@ -19,6 +19,7 @@
 #include "../../../../../Analyser/Static/AppleIIgs/Target.hpp"
 #include "../../../../../Analyser/Static/AtariST/Target.hpp"
 #include "../../../../../Analyser/Static/Commodore/Target.hpp"
+#include "../../../../../Analyser/Static/Enterprise/Target.hpp"
 #include "../../../../../Analyser/Static/Macintosh/Target.hpp"
 #include "../../../../../Analyser/Static/MSX/Target.hpp"
 #include "../../../../../Analyser/Static/Oric/Target.hpp"
@@ -130,6 +131,45 @@
 	return self;
 }
 
+- (instancetype)initWithEnterpriseModel:(CSMachineEnterpriseModel)model exosVersion:(CSMachineEnterpriseEXOS)exosVersion basicVersion:(CSMachineEnterpriseBASIC)basicVersion dos:(CSMachineEnterpriseDOS)dos {
+	self = [super init];
+	if(self) {
+		using Target = Analyser::Static::Enterprise::Target;
+		auto target = std::make_unique<Target>();
+
+		switch(model) {
+			case CSMachineEnterpriseModel64:		target->model = Target::Model::Enterprise64;		break;
+			default:
+			case CSMachineEnterpriseModel128:		target->model = Target::Model::Enterprise128;		break;
+			case CSMachineEnterpriseModel256:		target->model = Target::Model::Enterprise256;		break;
+		}
+
+		switch(exosVersion) {
+			case CSMachineEnterpriseEXOSVersion21:	target->exos_version = Target::EXOSVersion::v21;	break;
+			default:
+			case CSMachineEnterpriseEXOSVersion20:	target->exos_version = Target::EXOSVersion::v20;	break;
+			case CSMachineEnterpriseEXOSVersion10:	target->exos_version = Target::EXOSVersion::v10;	break;
+		}
+
+		switch(basicVersion) {
+			case CSMachineEnterpriseBASICNone:		target->basic_version = Target::BASICVersion::None;	break;
+			default:
+			case CSMachineEnterpriseBASICVersion21:	target->basic_version = Target::BASICVersion::v21;	break;
+			case CSMachineEnterpriseBASICVersion11:	target->basic_version = Target::BASICVersion::v11;	break;
+			case CSMachineEnterpriseBASICVersion10:	target->basic_version = Target::BASICVersion::v10;	break;
+		}
+
+		switch(dos) {
+			case CSMachineEnterpriseDOSEXDOS:		target->dos = Target::DOS::EXDOS;					break;
+			default:
+			case CSMachineEnterpriseDOSNone:		target->dos = Target::DOS::None;					break;
+		}
+
+		_targets.push_back(std::move(target));
+	}
+	return self;
+}
+
 - (instancetype)initWithMacintoshModel:(CSMachineMacintoshModel)model {
 	self = [super init];
 	if(self) {
@@ -276,6 +316,7 @@ static Analyser::Static::ZX8081::Target::MemoryModel ZX8081MemoryModelFromSize(K
 		case Analyser::Machine::AtariST:		return @"CompositeOptions";
 		case Analyser::Machine::ColecoVision:	return @"CompositeOptions";
 		case Analyser::Machine::Electron:		return @"QuickLoadCompositeOptions";
+		case Analyser::Machine::Enterprise:		return @"CompositeOptions";
 		case Analyser::Machine::Macintosh:		return @"MacintoshOptions";
 		case Analyser::Machine::MasterSystem:	return @"CompositeOptions";
 		case Analyser::Machine::MSX:			return @"QuickLoadCompositeOptions";
@@ -309,4 +350,8 @@ static Analyser::Static::ZX8081::Target::MemoryModel ZX8081MemoryModelFromSize(K
 	[machine applyMedia:_media];
 }
 
+- (BOOL)empty {
+	return _media.empty();
+}
+
 @end

OSBindings/Mac/Clock Signal/Machine/Wrappers/CSAppleII.h

@@ -0,0 +1,18 @@
+//
+//  CSAppleII.h
+//  Clock Signal
+//
+//  Created by Thomas Harte on 07/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+@class CSAppleII;
+#import "CSMachine.h"
+
+@interface CSAppleII : NSObject
+
+- (instancetype)initWithAppleII:(void *)appleII owner:(CSMachine *)machine;
+
+@property (nonatomic, assign) BOOL useSquarePixels;
+
+@end

OSBindings/Mac/Clock Signal/Machine/Wrappers/CSAppleII.mm

@@ -0,0 +1,57 @@
+//
+//  CSAppleII.m
+//  Clock Signal
+//
+//  Created by Thomas Harte on 07/06/2021.
+//  Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#import "CSAppleII.h"
+
+#include "AppleII.hpp"
+
+@implementation CSAppleII {
+	Apple::II::Machine *_appleII;
+	__weak CSMachine *_machine;
+}
+
+- (instancetype)initWithAppleII:(void *)appleII owner:(CSMachine *)machine {
+	self = [super init];
+	if(self) {
+		_appleII = (Apple::II::Machine *)appleII;
+		_machine = machine;
+	}
+	return self;
+}
+
+#pragma mark - Options
+
+- (void)setUseSquarePixels:(BOOL)useSquarePixels {
+	Configurable::Device *const configurable = dynamic_cast<Configurable::Device *>(_appleII);
+#ifndef NDEBUG
+	assert(configurable);
+#endif
+
+	@synchronized(_machine) {
+		auto options = configurable->get_options();
+#ifndef NDEBUG
+		assert(dynamic_cast<Apple::II::Machine::Options *>(options.get()));
+#endif
+
+		auto appleii_configurable = static_cast<Apple::II::Machine::Options *>(options.get());
+		appleii_configurable->use_square_pixels = useSquarePixels;
+		configurable->set_options(options);
+	}
+}
+
+- (BOOL)useSquarePixels {
+	Configurable::Device *const configurable = dynamic_cast<Configurable::Device *>(_appleII);
+
+	@synchronized(_machine) {
+		auto options = configurable->get_options();
+		auto appleii_configurable = dynamic_cast<Apple::II::Machine::Options *>(options.get());
+		return appleii_configurable->use_square_pixels ? YES : NO;
+	}
+}
+
+@end

OSBindings/Mac/Clock Signal/MachinePicker/Base.lproj/MachinePicker.xib

@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="17701" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="18122" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
     <dependencies>
         <deployment identifier="macosx"/>
-        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="17701"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="18122"/>
         <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
     </dependencies>
     <objects>
@@ -17,10 +17,10 @@
         <window title="Window" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" releasedWhenClosed="NO" visibleAtLaunch="NO" animationBehavior="default" titleVisibility="hidden" id="QvC-M9-y7g">
             <windowStyleMask key="styleMask" titled="YES" documentModal="YES"/>
             <windowPositionMask key="initialPositionMask" leftStrut="YES" rightStrut="YES" topStrut="YES" bottomStrut="YES"/>
-            <rect key="contentRect" x="196" y="240" width="590" height="316"/>
+            <rect key="contentRect" x="196" y="240" width="590" height="353"/>
             <rect key="screenRect" x="0.0" y="0.0" width="2560" height="1440"/>
             <view key="contentView" wantsLayer="YES" id="EiT-Mj-1SZ">
-                <rect key="frame" x="0.0" y="0.0" width="590" height="316"/>
+                <rect key="frame" x="0.0" y="0.0" width="590" height="353"/>
                 <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                 <subviews>
                     <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="hKn-1l-OSN">
@@ -59,16 +59,16 @@ Gw
                         </textFieldCell>
                     </textField>
                     <tabView type="noTabsBezelBorder" translatesAutoresizingMaskIntoConstraints="NO" id="VUb-QG-x7c">
-                        <rect key="frame" x="154" y="56" width="420" height="206"/>
+                        <rect key="frame" x="154" y="56" width="420" height="243"/>
                         <font key="font" metaFont="system"/>
                         <tabViewItems>
                             <tabViewItem label="Apple II" identifier="appleii" id="P59-QG-LOa">
                                 <view key="view" id="dHz-Yv-GNq">
-                                    <rect key="frame" x="10" y="7" width="400" height="186"/>
+                                    <rect key="frame" x="10" y="7" width="400" height="223"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="V5Z-dX-Ns4">
-                                            <rect key="frame" x="18" y="163" width="46" height="16"/>
+                                            <rect key="frame" x="18" y="185" width="46" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Model:" id="qV3-2P-3JW">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -76,7 +76,7 @@ Gw
                                             </textFieldCell>
                                         </textField>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="WnO-ef-IC6">
-                                            <rect key="frame" x="18" y="133" width="96" height="16"/>
+                                            <rect key="frame" x="18" y="155" width="96" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Disk controller:" id="kbf-rc-Y4M">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -84,7 +84,7 @@ Gw
                                             </textFieldCell>
                                         </textField>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="jli-ac-Sij">
-                                            <rect key="frame" x="67" y="157" width="117" height="25"/>
+                                            <rect key="frame" x="67" y="179" width="117" height="25"/>
                                             <popUpButtonCell key="cell" type="push" title="Apple II" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" imageScaling="axesIndependently" inset="2" selectedItem="VBQ-JG-AeM" id="U6V-us-O2F">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
@@ -99,7 +99,7 @@ Gw
                                             </popUpButtonCell>
                                         </popUpButton>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="LSB-WP-FMi">
-                                            <rect key="frame" x="117" y="127" width="134" height="25"/>
+                                            <rect key="frame" x="117" y="149" width="134" height="25"/>
                                             <popUpButtonCell key="cell" type="push" title="Sixteen Sector" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" tag="16" imageScaling="axesIndependently" inset="2" selectedItem="QaV-Yr-k9o" id="8BT-RV-2Nm">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
@@ -115,11 +115,11 @@ Gw
                                     </subviews>
                                     <constraints>
                                         <constraint firstItem="WnO-ef-IC6" firstAttribute="leading" secondItem="dHz-Yv-GNq" secondAttribute="leading" constant="20" symbolic="YES" id="5RF-1w-9HW"/>
-                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="LSB-WP-FMi" secondAttribute="bottom" constant="5" id="865-cv-qVk"/>
+                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="LSB-WP-FMi" secondAttribute="bottom" constant="20" symbolic="YES" id="865-cv-qVk"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="LSB-WP-FMi" secondAttribute="trailing" constant="20" symbolic="YES" id="9GL-al-1qi"/>
                                         <constraint firstItem="WnO-ef-IC6" firstAttribute="centerY" secondItem="LSB-WP-FMi" secondAttribute="centerY" id="Fuj-zT-MIm"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="jli-ac-Sij" secondAttribute="trailing" constant="20" symbolic="YES" id="I8d-OR-ICN"/>
-                                        <constraint firstItem="jli-ac-Sij" firstAttribute="top" secondItem="dHz-Yv-GNq" secondAttribute="top" constant="5" id="Qi1-CV-A0c"/>
+                                        <constraint firstItem="jli-ac-Sij" firstAttribute="top" secondItem="dHz-Yv-GNq" secondAttribute="top" constant="20" symbolic="YES" id="Qi1-CV-A0c"/>
                                         <constraint firstItem="V5Z-dX-Ns4" firstAttribute="leading" secondItem="dHz-Yv-GNq" secondAttribute="leading" constant="20" symbolic="YES" id="SWc-iX-1We"/>
                                         <constraint firstItem="LSB-WP-FMi" firstAttribute="leading" secondItem="WnO-ef-IC6" secondAttribute="trailing" constant="8" symbolic="YES" id="bte-XA-xNQ"/>
                                         <constraint firstItem="LSB-WP-FMi" firstAttribute="top" secondItem="jli-ac-Sij" secondAttribute="bottom" constant="10" symbolic="YES" id="ki5-JR-vRe"/>
@@ -129,12 +129,12 @@ Gw
                                 </view>
                             </tabViewItem>
                             <tabViewItem label="Apple IIgs" identifier="appleiigs" id="u5E-8n-ghF">
-                                <view key="view" ambiguous="YES" id="jOM-9f-vkk">
-                                    <rect key="frame" x="10" y="7" width="400" height="76"/>
+                                <view key="view" id="jOM-9f-vkk">
+                                    <rect key="frame" x="10" y="7" width="400" height="223"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="0d9-IG-gKU">
-                                            <rect key="frame" x="18" y="53" width="46" height="16"/>
+                                            <rect key="frame" x="18" y="185" width="46" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Model:" id="kiv-1P-FWc">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -142,7 +142,7 @@ Gw
                                             </textFieldCell>
                                         </textField>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="LES-76-Ovz">
-                                            <rect key="frame" x="18" y="23" width="85" height="16"/>
+                                            <rect key="frame" x="18" y="155" width="85" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Memory size:" id="OLJ-nC-yyj">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -150,7 +150,7 @@ Gw
                                             </textFieldCell>
                                         </textField>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="gcS-uy-mzl">
-                                            <rect key="frame" x="67" y="47" width="89" height="25"/>
+                                            <rect key="frame" x="67" y="179" width="89" height="25"/>
                                             <popUpButtonCell key="cell" type="push" title="ROM 03" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" tag="2" imageScaling="axesIndependently" inset="2" selectedItem="0TS-DO-O9h" id="hjw-g8-e2f">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
@@ -164,7 +164,7 @@ Gw
                                             </popUpButtonCell>
                                         </popUpButton>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="nQa-YS-utT">
-                                            <rect key="frame" x="106" y="17" width="82" height="25"/>
+                                            <rect key="frame" x="106" y="149" width="82" height="25"/>
                                             <popUpButtonCell key="cell" type="push" title="8 mb" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" tag="8192" imageScaling="axesIndependently" inset="2" selectedItem="UHg-gU-Xnn" id="dl3-cq-uWO">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
@@ -182,24 +182,24 @@ Gw
                                         <constraint firstItem="LES-76-Ovz" firstAttribute="leading" secondItem="jOM-9f-vkk" secondAttribute="leading" constant="20" symbolic="YES" id="2D3-Ve-6CN"/>
                                         <constraint firstItem="0d9-IG-gKU" firstAttribute="leading" secondItem="jOM-9f-vkk" secondAttribute="leading" constant="20" symbolic="YES" id="8Xz-86-tDf"/>
                                         <constraint firstItem="0d9-IG-gKU" firstAttribute="centerY" secondItem="gcS-uy-mzl" secondAttribute="centerY" id="Eww-Qq-eBT"/>
-                                        <constraint firstItem="gcS-uy-mzl" firstAttribute="top" secondItem="jOM-9f-vkk" secondAttribute="top" constant="5" id="F6i-cP-7AR"/>
+                                        <constraint firstItem="gcS-uy-mzl" firstAttribute="top" secondItem="jOM-9f-vkk" secondAttribute="top" constant="20" symbolic="YES" id="F6i-cP-7AR"/>
                                         <constraint firstItem="gcS-uy-mzl" firstAttribute="leading" secondItem="0d9-IG-gKU" secondAttribute="trailing" constant="8" symbolic="YES" id="LUm-rI-LYP"/>
                                         <constraint firstItem="LES-76-Ovz" firstAttribute="centerY" secondItem="nQa-YS-utT" secondAttribute="centerY" id="UdP-U6-OFE"/>
                                         <constraint firstItem="nQa-YS-utT" firstAttribute="leading" secondItem="LES-76-Ovz" secondAttribute="trailing" constant="8" symbolic="YES" id="Xm1-iG-Dgj"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="gcS-uy-mzl" secondAttribute="trailing" constant="20" symbolic="YES" id="a38-Cx-CEh"/>
                                         <constraint firstItem="nQa-YS-utT" firstAttribute="top" secondItem="gcS-uy-mzl" secondAttribute="bottom" constant="10" symbolic="YES" id="aM9-m8-s7z"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="nQa-YS-utT" secondAttribute="trailing" constant="20" symbolic="YES" id="cqx-Jc-rUb"/>
-                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="nQa-YS-utT" secondAttribute="bottom" constant="5" id="sbT-If-NTU"/>
+                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="nQa-YS-utT" secondAttribute="bottom" constant="20" symbolic="YES" id="sbT-If-NTU"/>
                                     </constraints>
                                 </view>
                             </tabViewItem>
                             <tabViewItem label="Amstrad CPC" identifier="cpc" id="JmB-OF-xcM">
                                 <view key="view" id="5zS-Nj-Ynx">
-                                    <rect key="frame" x="10" y="7" width="400" height="76"/>
+                                    <rect key="frame" x="10" y="7" width="400" height="223"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="00d-sg-Krh">
-                                            <rect key="frame" x="67" y="47" width="96" height="25"/>
+                                            <rect key="frame" x="67" y="179" width="96" height="25"/>
                                             <popUpButtonCell key="cell" type="push" title="CPC6128" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" tag="6128" imageScaling="axesIndependently" inset="2" selectedItem="klh-ZE-Agp" id="hVJ-h6-iea">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
@@ -213,7 +213,7 @@ Gw
                                             </popUpButtonCell>
                                         </popUpButton>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="q9q-sl-J0q">
-                                            <rect key="frame" x="18" y="53" width="46" height="16"/>
+                                            <rect key="frame" x="18" y="185" width="46" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Model:" id="Cw3-q5-1bC">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -224,8 +224,8 @@ Gw
                                     <constraints>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="00d-sg-Krh" secondAttribute="trailing" constant="20" symbolic="YES" id="4AF-5C-2IF"/>
                                         <constraint firstItem="q9q-sl-J0q" firstAttribute="leading" secondItem="5zS-Nj-Ynx" secondAttribute="leading" constant="20" symbolic="YES" id="Wof-5h-gfD"/>
-                                        <constraint firstItem="00d-sg-Krh" firstAttribute="top" secondItem="5zS-Nj-Ynx" secondAttribute="top" constant="5" id="c92-uU-NRr"/>
-                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="00d-sg-Krh" secondAttribute="bottom" constant="5" id="enU-LN-Nep"/>
+                                        <constraint firstItem="00d-sg-Krh" firstAttribute="top" secondItem="5zS-Nj-Ynx" secondAttribute="top" constant="20" symbolic="YES" id="c92-uU-NRr"/>
+                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="00d-sg-Krh" secondAttribute="bottom" constant="20" symbolic="YES" id="enU-LN-Nep"/>
                                         <constraint firstItem="00d-sg-Krh" firstAttribute="leading" secondItem="q9q-sl-J0q" secondAttribute="trailing" constant="8" symbolic="YES" id="mA8-US-ndo"/>
                                         <constraint firstItem="q9q-sl-J0q" firstAttribute="centerY" secondItem="00d-sg-Krh" secondAttribute="centerY" id="vA8-IA-Uwf"/>
                                     </constraints>
@@ -233,11 +233,11 @@ Gw
                             </tabViewItem>
                             <tabViewItem label="Atari ST" identifier="atarist" id="a6Y-mx-yFn">
                                 <view key="view" id="nnv-Wi-7hc">
-                                    <rect key="frame" x="10" y="7" width="400" height="76"/>
+                                    <rect key="frame" x="10" y="7" width="400" height="223"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="nLf-LI-nWO">
-                                            <rect key="frame" x="18" y="57" width="728" height="16"/>
+                                            <rect key="frame" x="18" y="204" width="364" height="16"/>
                                             <textFieldCell key="cell" lineBreakMode="clipping" title="At present only a 512k Atari ST is supported." id="gBA-ke-mur">
                                                 <font key="font" usesAppearanceFont="YES"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -254,32 +254,32 @@ Gw
                             </tabViewItem>
                             <tabViewItem label="Electron" identifier="electron" id="muc-z9-Vqc">
                                 <view key="view" id="SRc-2D-95G">
-                                    <rect key="frame" x="10" y="7" width="400" height="76"/>
+                                    <rect key="frame" x="10" y="7" width="400" height="223"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
                                         <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="JqM-IK-FMP">
-                                            <rect key="frame" x="18" y="56" width="168" height="18"/>
+                                            <rect key="frame" x="18" y="186" width="168" height="18"/>
                                             <buttonCell key="cell" type="check" title="With Disk Filing System" bezelStyle="regularSquare" imagePosition="left" state="on" inset="2" id="tpW-5C-xKp">
                                                 <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
                                                 <font key="font" metaFont="system"/>
                                             </buttonCell>
                                         </button>
                                         <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="945-wU-JOH">
-                                            <rect key="frame" x="18" y="34" width="232" height="18"/>
+                                            <rect key="frame" x="18" y="164" width="232" height="18"/>
                                             <buttonCell key="cell" type="check" title="With Advanced Disk Filing System" bezelStyle="regularSquare" imagePosition="left" state="on" inset="2" id="S0c-Jg-7Pu">
                                                 <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
                                                 <font key="font" metaFont="system"/>
                                             </buttonCell>
                                         </button>
                                         <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="cG2-Ph-S3Z">
-                                            <rect key="frame" x="18" y="12" width="231" height="18"/>
+                                            <rect key="frame" x="18" y="142" width="231" height="18"/>
                                             <buttonCell key="cell" type="check" title="With Advanced Plus 6 Utility ROM" bezelStyle="regularSquare" imagePosition="left" state="on" inset="2" id="yjF-XS-zx6">
                                                 <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
                                                 <font key="font" metaFont="system"/>
                                             </buttonCell>
                                         </button>
                                         <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="lzo-8g-o4S">
-                                            <rect key="frame" x="18" y="-10" width="284" height="18"/>
+                                            <rect key="frame" x="18" y="120" width="284" height="18"/>
                                             <buttonCell key="cell" type="check" title="Fill unused ROM banks with sideways RAM" bezelStyle="regularSquare" imagePosition="left" state="on" inset="2" id="JEz-eK-uWp">
                                                 <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
                                                 <font key="font" metaFont="system"/>
@@ -289,13 +289,13 @@ Gw
                                     <constraints>
                                         <constraint firstItem="945-wU-JOH" firstAttribute="leading" secondItem="SRc-2D-95G" secondAttribute="leading" constant="20" symbolic="YES" id="1iM-70-oZq"/>
                                         <constraint firstItem="cG2-Ph-S3Z" firstAttribute="top" secondItem="945-wU-JOH" secondAttribute="bottom" constant="6" symbolic="YES" id="E9b-RP-9vj"/>
-                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="lzo-8g-o4S" secondAttribute="bottom" constant="5" id="FM6-AA-Vhf"/>
+                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="lzo-8g-o4S" secondAttribute="bottom" constant="20" symbolic="YES" id="FM6-AA-Vhf"/>
                                         <constraint firstItem="JqM-IK-FMP" firstAttribute="leading" secondItem="SRc-2D-95G" secondAttribute="leading" constant="20" symbolic="YES" id="NfY-dE-aJw"/>
                                         <constraint firstItem="lzo-8g-o4S" firstAttribute="top" secondItem="cG2-Ph-S3Z" secondAttribute="bottom" constant="6" symbolic="YES" id="S45-42-Gtv"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="lzo-8g-o4S" secondAttribute="trailing" constant="20" symbolic="YES" id="X3p-qJ-ENH"/>
                                         <constraint firstItem="lzo-8g-o4S" firstAttribute="leading" secondItem="SRc-2D-95G" secondAttribute="leading" constant="20" symbolic="YES" id="b5a-SX-2ty"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="945-wU-JOH" secondAttribute="trailing" constant="20" symbolic="YES" id="dmY-PV-ap4"/>
-                                        <constraint firstItem="JqM-IK-FMP" firstAttribute="top" secondItem="SRc-2D-95G" secondAttribute="top" constant="3" id="ggl-QH-mV4"/>
+                                        <constraint firstItem="JqM-IK-FMP" firstAttribute="top" secondItem="SRc-2D-95G" secondAttribute="top" constant="20" symbolic="YES" id="ggl-QH-mV4"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="cG2-Ph-S3Z" secondAttribute="trailing" constant="20" symbolic="YES" id="m6t-dP-71d"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="JqM-IK-FMP" secondAttribute="trailing" constant="20" symbolic="YES" id="mvO-UZ-BtT"/>
                                         <constraint firstItem="cG2-Ph-S3Z" firstAttribute="leading" secondItem="SRc-2D-95G" secondAttribute="leading" constant="20" symbolic="YES" id="npw-IZ-6xU"/>
@@ -303,13 +303,133 @@ Gw
                                     </constraints>
                                 </view>
                             </tabViewItem>
+                            <tabViewItem label="Enterprise" identifier="enterprise" id="zhO-EO-wUe">
+                                <view key="view" id="1cs-PX-RAH">
+                                    <rect key="frame" x="10" y="7" width="400" height="223"/>
+                                    <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                                    <subviews>
+                                        <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="PhH-bu-pb5">
+                                            <rect key="frame" x="80" y="179" width="129" height="25"/>
+                                            <popUpButtonCell key="cell" type="push" title="Enterprise 128" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" tag="128" imageScaling="axesIndependently" inset="2" selectedItem="roH-nL-f8o" id="z9O-XC-XBv">
+                                                <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
+                                                <font key="font" metaFont="menu"/>
+                                                <menu key="menu" id="ojI-Vb-iHz">
+                                                    <items>
+                                                        <menuItem title="Enterprise 256" tag="256" id="Al3-A0-tvw"/>
+                                                        <menuItem title="Enterprise 128" state="on" tag="128" id="roH-nL-f8o"/>
+                                                        <menuItem title="Enterprise 64" tag="64" id="vNG-Tv-bDI"/>
+                                                    </items>
+                                                </menu>
+                                            </popUpButtonCell>
+                                        </popUpButton>
+                                        <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="nen-Za-7zH">
+                                            <rect key="frame" x="64" y="149" width="107" height="25"/>
+                                            <popUpButtonCell key="cell" type="push" title="Version 2.1" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" tag="21" imageScaling="axesIndependently" inset="2" selectedItem="Qja-xZ-wVM" id="xGG-ri-8Sb">
+                                                <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
+                                                <font key="font" metaFont="menu"/>
+                                                <menu key="menu" id="uNC-hA-d5z">
+                                                    <items>
+                                                        <menuItem title="Version 2.1" state="on" tag="21" id="Qja-xZ-wVM"/>
+                                                        <menuItem title="Version 2.0" tag="20" id="XTj-l7-KX3"/>
+                                                        <menuItem title="Version 1.0" tag="10" id="Ky2-2D-wcY"/>
+                                                    </items>
+                                                </menu>
+                                            </popUpButtonCell>
+                                        </popUpButton>
+                                        <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="hIr-GH-7xi">
+                                            <rect key="frame" x="67" y="119" width="105" height="25"/>
+                                            <popUpButtonCell key="cell" type="push" title="Version 2.1" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" tag="21" imageScaling="axesIndependently" inset="2" selectedItem="TME-cv-Jh1" id="9mQ-GW-lq9">
+                                                <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
+                                                <font key="font" metaFont="menu"/>
+                                                <menu key="menu" id="VcH-Xm-1hY">
+                                                    <items>
+                                                        <menuItem title="Version 2.1" state="on" tag="21" id="TME-cv-Jh1"/>
+                                                        <menuItem title="Version 1.1" tag="11" id="7P2-aF-6fp"/>
+                                                        <menuItem title="Version 1.0" tag="10" id="j8p-uY-BhG"/>
+                                                        <menuItem title="None" id="eGk-Bj-IVT"/>
+                                                    </items>
+                                                </menu>
+                                            </popUpButtonCell>
+                                        </popUpButton>
+                                        <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="syE-e7-TjU">
+                                            <rect key="frame" x="57" y="89" width="83" height="25"/>
+                                            <popUpButtonCell key="cell" type="push" title="EXDOS" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" borderStyle="borderAndBezel" tag="1" imageScaling="axesIndependently" inset="2" selectedItem="8rP-2w-PdU" id="NvO-Zm-2Rq">
+                                                <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
+                                                <font key="font" metaFont="menu"/>
+                                                <menu key="menu" title="DOS" id="sdr-al-7mi">
+                                                    <items>
+                                                        <menuItem title="EXDOS" tag="1" id="8rP-2w-PdU"/>
+                                                        <menuItem title="None" state="on" id="qoS-KO-iEZ"/>
+                                                    </items>
+                                                </menu>
+                                            </popUpButtonCell>
+                                        </popUpButton>
+                                        <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="ykc-W1-YaS">
+                                            <rect key="frame" x="18" y="155" width="43" height="16"/>
+                                            <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="EXOS:" id="gUC-PN-zVL">
+                                                <font key="font" metaFont="system"/>
+                                                <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
+                                                <color key="backgroundColor" name="controlColor" catalog="System" colorSpace="catalog"/>
+                                            </textFieldCell>
+                                        </textField>
+                                        <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="frx-nk-c3P">
+                                            <rect key="frame" x="18" y="185" width="59" height="16"/>
+                                            <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Machine:" id="uTv-hH-mIC">
+                                                <font key="font" metaFont="system"/>
+                                                <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
+                                                <color key="backgroundColor" name="controlColor" catalog="System" colorSpace="catalog"/>
+                                            </textFieldCell>
+                                        </textField>
+                                        <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="dzd-tH-BjX">
+                                            <rect key="frame" x="18" y="125" width="46" height="16"/>
+                                            <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="BASIC:" id="ai1-oR-X6Y">
+                                                <font key="font" metaFont="system"/>
+                                                <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
+                                                <color key="backgroundColor" name="controlColor" catalog="System" colorSpace="catalog"/>
+                                            </textFieldCell>
+                                        </textField>
+                                        <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="pxr-Bq-yh0">
+                                            <rect key="frame" x="18" y="95" width="36" height="16"/>
+                                            <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="DOS:" id="NFk-cp-DfS">
+                                                <font key="font" metaFont="system"/>
+                                                <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
+                                                <color key="backgroundColor" name="controlColor" catalog="System" colorSpace="catalog"/>
+                                            </textFieldCell>
+                                        </textField>
+                                    </subviews>
+                                    <constraints>
+                                        <constraint firstItem="dzd-tH-BjX" firstAttribute="centerY" secondItem="hIr-GH-7xi" secondAttribute="centerY" id="3TV-RU-Kgh"/>
+                                        <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="hIr-GH-7xi" secondAttribute="trailing" constant="20" symbolic="YES" id="44v-9O-y7L"/>
+                                        <constraint firstItem="frx-nk-c3P" firstAttribute="centerY" secondItem="PhH-bu-pb5" secondAttribute="centerY" id="6Wc-aR-wuL"/>
+                                        <constraint firstItem="dzd-tH-BjX" firstAttribute="leading" secondItem="1cs-PX-RAH" secondAttribute="leading" constant="20" symbolic="YES" id="7RZ-Om-TAa"/>
+                                        <constraint firstItem="ykc-W1-YaS" firstAttribute="centerY" secondItem="nen-Za-7zH" secondAttribute="centerY" id="CLa-6E-8BB"/>
+                                        <constraint firstItem="PhH-bu-pb5" firstAttribute="leading" secondItem="frx-nk-c3P" secondAttribute="trailing" constant="8" symbolic="YES" id="ENF-TY-TQ7"/>
+                                        <constraint firstItem="nen-Za-7zH" firstAttribute="leading" secondItem="ykc-W1-YaS" secondAttribute="trailing" constant="8" symbolic="YES" id="GWR-VI-9PG"/>
+                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="syE-e7-TjU" secondAttribute="bottom" constant="20" symbolic="YES" id="K3s-FA-zMB"/>
+                                        <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="PhH-bu-pb5" secondAttribute="trailing" constant="20" symbolic="YES" id="LwB-ef-uF4"/>
+                                        <constraint firstItem="PhH-bu-pb5" firstAttribute="top" secondItem="1cs-PX-RAH" secondAttribute="top" constant="20" symbolic="YES" id="Myt-i4-jVq"/>
+                                        <constraint firstItem="pxr-Bq-yh0" firstAttribute="leading" secondItem="1cs-PX-RAH" secondAttribute="leading" constant="20" symbolic="YES" id="Qzp-IY-Pa0"/>
+                                        <constraint firstItem="PhH-bu-pb5" firstAttribute="leading" secondItem="frx-nk-c3P" secondAttribute="trailing" constant="8" symbolic="YES" id="T3e-u7-fiQ"/>
+                                        <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="syE-e7-TjU" secondAttribute="trailing" constant="20" symbolic="YES" id="TEX-Nw-y2K"/>
+                                        <constraint firstItem="frx-nk-c3P" firstAttribute="leading" secondItem="1cs-PX-RAH" secondAttribute="leading" constant="20" symbolic="YES" id="TgR-RR-eA1"/>
+                                        <constraint firstItem="pxr-Bq-yh0" firstAttribute="centerY" secondItem="syE-e7-TjU" secondAttribute="centerY" id="UYw-uz-Am0"/>
+                                        <constraint firstItem="hIr-GH-7xi" firstAttribute="top" secondItem="nen-Za-7zH" secondAttribute="bottom" constant="10" symbolic="YES" id="VOc-2v-s3u"/>
+                                        <constraint firstItem="syE-e7-TjU" firstAttribute="top" secondItem="hIr-GH-7xi" secondAttribute="bottom" constant="10" symbolic="YES" id="W9S-on-Heq"/>
+                                        <constraint firstItem="nen-Za-7zH" firstAttribute="top" secondItem="PhH-bu-pb5" secondAttribute="bottom" constant="10" symbolic="YES" id="Yes-o3-V0m"/>
+                                        <constraint firstItem="ykc-W1-YaS" firstAttribute="leading" secondItem="1cs-PX-RAH" secondAttribute="leading" constant="20" symbolic="YES" id="bAP-lx-pdi"/>
+                                        <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="nen-Za-7zH" secondAttribute="trailing" constant="20" symbolic="YES" id="eEI-5Q-TnO"/>
+                                        <constraint firstItem="syE-e7-TjU" firstAttribute="leading" secondItem="pxr-Bq-yh0" secondAttribute="trailing" constant="8" symbolic="YES" id="fmM-Ma-Jyu"/>
+                                        <constraint firstItem="hIr-GH-7xi" firstAttribute="leading" secondItem="dzd-tH-BjX" secondAttribute="trailing" constant="8" symbolic="YES" id="jDQ-TF-Ogf"/>
+                                    </constraints>
+                                </view>
+                            </tabViewItem>
                             <tabViewItem label="Macintosh" identifier="mac" id="lmR-z3-xSm">
                                 <view key="view" id="7Yf-vi-Q0W">
-                                    <rect key="frame" x="10" y="7" width="400" height="76"/>
+                                    <rect key="frame" x="10" y="7" width="400" height="223"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="ZOY-4E-Cfl">
-                                            <rect key="frame" x="18" y="53" width="46" height="16"/>
+                                            <rect key="frame" x="18" y="185" width="46" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Model:" id="h9r-i6-66j">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -317,7 +437,7 @@ Gw
                                             </textFieldCell>
                                         </textField>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="xa6-NA-JY5">
-                                            <rect key="frame" x="67" y="47" width="75" height="25"/>
+                                            <rect key="frame" x="67" y="179" width="75" height="25"/>
                                             <popUpButtonCell key="cell" type="push" title="Plus" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" tag="3" imageScaling="axesIndependently" inset="2" selectedItem="R6T-hg-rOF" id="1Kb-Q2-BGM">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
@@ -333,9 +453,9 @@ Gw
                                         </popUpButton>
                                     </subviews>
                                     <constraints>
-                                        <constraint firstItem="xa6-NA-JY5" firstAttribute="top" secondItem="7Yf-vi-Q0W" secondAttribute="top" constant="5" id="3hY-Ca-mnR"/>
+                                        <constraint firstItem="xa6-NA-JY5" firstAttribute="top" secondItem="7Yf-vi-Q0W" secondAttribute="top" constant="20" symbolic="YES" id="3hY-Ca-mnR"/>
                                         <constraint firstItem="ZOY-4E-Cfl" firstAttribute="leading" secondItem="7Yf-vi-Q0W" secondAttribute="leading" constant="20" symbolic="YES" id="5s6-87-VT6"/>
-                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="xa6-NA-JY5" secondAttribute="bottom" constant="5" id="KYf-GJ-Y7k"/>
+                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="xa6-NA-JY5" secondAttribute="bottom" constant="20" symbolic="YES" id="KYf-GJ-Y7k"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="xa6-NA-JY5" secondAttribute="trailing" constant="20" symbolic="YES" id="LZ5-xH-fU0"/>
                                         <constraint firstItem="ZOY-4E-Cfl" firstAttribute="centerY" secondItem="xa6-NA-JY5" secondAttribute="centerY" id="Wa5-KX-3Me"/>
                                         <constraint firstItem="xa6-NA-JY5" firstAttribute="leading" secondItem="ZOY-4E-Cfl" secondAttribute="trailing" constant="8" symbolic="YES" id="ktS-sr-F8L"/>
@@ -344,18 +464,18 @@ Gw
                             </tabViewItem>
                             <tabViewItem label="MSX" identifier="msx" id="6SR-DY-zdI">
                                 <view key="view" id="mWD-An-tR7">
-                                    <rect key="frame" x="10" y="7" width="400" height="76"/>
+                                    <rect key="frame" x="10" y="7" width="400" height="223"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
                                         <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="8xT-Pr-8SE">
-                                            <rect key="frame" x="18" y="26" width="128" height="18"/>
+                                            <rect key="frame" x="18" y="158" width="128" height="18"/>
                                             <buttonCell key="cell" type="check" title="Attach disk drive" bezelStyle="regularSquare" imagePosition="left" state="on" inset="2" id="CB3-nA-VTM">
                                                 <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
                                                 <font key="font" metaFont="system"/>
                                             </buttonCell>
                                         </button>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="LG6-mP-SeG">
-                                            <rect key="frame" x="71" y="47" width="146" height="25"/>
+                                            <rect key="frame" x="71" y="179" width="146" height="25"/>
                                             <popUpButtonCell key="cell" type="push" title="European (PAL)" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" imageScaling="axesIndependently" inset="2" selectedItem="xAh-Ch-tby" id="yR4-yv-Lvu">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
@@ -369,7 +489,7 @@ Gw
                                             </popUpButtonCell>
                                         </popUpButton>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="ZaD-7v-rMS">
-                                            <rect key="frame" x="18" y="53" width="50" height="16"/>
+                                            <rect key="frame" x="18" y="185" width="50" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Region:" id="x4m-eh-Nif">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -380,9 +500,9 @@ Gw
                                     <constraints>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="LG6-mP-SeG" secondAttribute="trailing" constant="20" symbolic="YES" id="0Oc-n7-gaM"/>
                                         <constraint firstItem="8xT-Pr-8SE" firstAttribute="top" secondItem="LG6-mP-SeG" secondAttribute="bottom" constant="8" symbolic="YES" id="LBt-4m-GDc"/>
-                                        <constraint firstItem="LG6-mP-SeG" firstAttribute="top" secondItem="mWD-An-tR7" secondAttribute="top" constant="5" id="bcb-ZZ-VpQ"/>
+                                        <constraint firstItem="LG6-mP-SeG" firstAttribute="top" secondItem="mWD-An-tR7" secondAttribute="top" constant="20" symbolic="YES" id="bcb-ZZ-VpQ"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="8xT-Pr-8SE" secondAttribute="trailing" constant="20" symbolic="YES" id="l8P-UW-8ig"/>
-                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="8xT-Pr-8SE" secondAttribute="bottom" constant="3" id="mga-YX-Bek"/>
+                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="8xT-Pr-8SE" secondAttribute="bottom" constant="20" symbolic="YES" id="mga-YX-Bek"/>
                                         <constraint firstItem="8xT-Pr-8SE" firstAttribute="leading" secondItem="mWD-An-tR7" secondAttribute="leading" constant="20" symbolic="YES" id="q8Q-kh-Opj"/>
                                         <constraint firstItem="LG6-mP-SeG" firstAttribute="leading" secondItem="ZaD-7v-rMS" secondAttribute="trailing" constant="8" symbolic="YES" id="svb-nH-GlP"/>
                                         <constraint firstItem="ZaD-7v-rMS" firstAttribute="leading" secondItem="mWD-An-tR7" secondAttribute="leading" constant="20" symbolic="YES" id="zgh-a5-FNF"/>
@@ -392,11 +512,11 @@ Gw
                             </tabViewItem>
                             <tabViewItem label="Oric" identifier="oric" id="NSx-DC-p4M">
                                 <view key="view" id="sOR-e0-8iZ">
-                                    <rect key="frame" x="10" y="7" width="400" height="76"/>
+                                    <rect key="frame" x="10" y="7" width="400" height="223"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="0ct-tf-uRH">
-                                            <rect key="frame" x="18" y="53" width="46" height="16"/>
+                                            <rect key="frame" x="18" y="185" width="46" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Model:" id="Xm1-7x-YVl">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -404,7 +524,7 @@ Gw
                                             </textFieldCell>
                                         </textField>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="ENP-hI-BVZ">
-                                            <rect key="frame" x="67" y="47" width="107" height="25"/>
+                                            <rect key="frame" x="67" y="179" width="107" height="25"/>
                                             <popUpButtonCell key="cell" type="push" title="Oric-1" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" imageScaling="axesIndependently" inset="2" selectedItem="jGN-1a-biF" id="Jll-EJ-cMr">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
@@ -418,7 +538,7 @@ Gw
                                             </popUpButtonCell>
                                         </popUpButton>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="fYL-p6-wyn">
-                                            <rect key="frame" x="113" y="17" width="130" height="25"/>
+                                            <rect key="frame" x="113" y="149" width="130" height="25"/>
                                             <popUpButtonCell key="cell" type="push" title="None" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" imageScaling="axesIndependently" inset="2" selectedItem="XhK-Jh-oTW" id="aYb-m1-H9X">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
@@ -434,7 +554,7 @@ Gw
                                             </popUpButtonCell>
                                         </popUpButton>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="okM-ZI-NbF">
-                                            <rect key="frame" x="18" y="23" width="92" height="16"/>
+                                            <rect key="frame" x="18" y="155" width="92" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Disk interface:" id="SFK-hS-tFC">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -443,7 +563,7 @@ Gw
                                         </textField>
                                     </subviews>
                                     <constraints>
-                                        <constraint firstItem="ENP-hI-BVZ" firstAttribute="top" secondItem="sOR-e0-8iZ" secondAttribute="top" constant="5" id="Bgq-8R-8I4"/>
+                                        <constraint firstItem="ENP-hI-BVZ" firstAttribute="top" secondItem="sOR-e0-8iZ" secondAttribute="top" constant="20" symbolic="YES" id="Bgq-8R-8I4"/>
                                         <constraint firstItem="fYL-p6-wyn" firstAttribute="leading" secondItem="okM-ZI-NbF" secondAttribute="trailing" constant="8" symbolic="YES" id="Pra-lC-JPB"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="ENP-hI-BVZ" secondAttribute="trailing" constant="20" symbolic="YES" id="Sr5-QZ-xU3"/>
                                         <constraint firstItem="ENP-hI-BVZ" firstAttribute="leading" secondItem="0ct-tf-uRH" secondAttribute="trailing" constant="8" symbolic="YES" id="Wcg-1P-z6l"/>
@@ -453,17 +573,17 @@ Gw
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="fYL-p6-wyn" secondAttribute="trailing" constant="20" symbolic="YES" id="ewV-Dw-zj2"/>
                                         <constraint firstItem="0ct-tf-uRH" firstAttribute="leading" secondItem="sOR-e0-8iZ" secondAttribute="leading" constant="20" symbolic="YES" id="huH-9L-97Y"/>
                                         <constraint firstItem="fYL-p6-wyn" firstAttribute="top" secondItem="ENP-hI-BVZ" secondAttribute="bottom" constant="10" symbolic="YES" id="l3T-Ve-0Jw"/>
-                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="fYL-p6-wyn" secondAttribute="bottom" constant="5" id="mN9-AZ-wSn"/>
+                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="fYL-p6-wyn" secondAttribute="bottom" constant="20" symbolic="YES" id="mN9-AZ-wSn"/>
                                     </constraints>
                                 </view>
                             </tabViewItem>
                             <tabViewItem label="Vic-20" identifier="vic20" id="cyO-PU-hSU">
                                 <view key="view" id="fLI-XB-QCr">
-                                    <rect key="frame" x="10" y="7" width="400" height="76"/>
+                                    <rect key="frame" x="10" y="7" width="400" height="223"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="ueK-gq-gaF">
-                                            <rect key="frame" x="71" y="47" width="146" height="25"/>
+                                            <rect key="frame" x="71" y="179" width="146" height="25"/>
                                             <popUpButtonCell key="cell" type="push" title="European (PAL)" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" imageScaling="axesIndependently" inset="2" selectedItem="45i-0n-gau" id="yi7-eo-I0q">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
@@ -479,7 +599,7 @@ Gw
                                             </popUpButtonCell>
                                         </popUpButton>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="2eV-Us-eEv">
-                                            <rect key="frame" x="108" y="17" width="116" height="25"/>
+                                            <rect key="frame" x="108" y="149" width="116" height="25"/>
                                             <popUpButtonCell key="cell" type="push" title="Unexpanded" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" imageScaling="axesIndependently" inset="2" selectedItem="fOl-8Q-fsA" id="rH0-7T-pJE">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
@@ -493,7 +613,7 @@ Gw
                                             </popUpButtonCell>
                                         </popUpButton>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="MTh-9p-FqC">
-                                            <rect key="frame" x="18" y="53" width="50" height="16"/>
+                                            <rect key="frame" x="18" y="185" width="50" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Region:" id="F3g-Ya-ypU">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -501,7 +621,7 @@ Gw
                                             </textFieldCell>
                                         </textField>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="gRS-DK-rIy">
-                                            <rect key="frame" x="18" y="23" width="87" height="16"/>
+                                            <rect key="frame" x="18" y="155" width="87" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Memory Size:" id="a4I-vG-yCp">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -509,7 +629,7 @@ Gw
                                             </textFieldCell>
                                         </textField>
                                         <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="Lrf-gL-6EI">
-                                            <rect key="frame" x="18" y="-4" width="177" height="18"/>
+                                            <rect key="frame" x="18" y="128" width="177" height="18"/>
                                             <buttonCell key="cell" type="check" title="Attach C-1540 disk drive" bezelStyle="regularSquare" imagePosition="left" state="on" inset="2" id="tsq-YD-xw8">
                                                 <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
                                                 <font key="font" metaFont="system"/>
@@ -521,7 +641,7 @@ Gw
                                         <constraint firstItem="MTh-9p-FqC" firstAttribute="centerY" secondItem="ueK-gq-gaF" secondAttribute="centerY" id="8KD-Bm-KRA"/>
                                         <constraint firstItem="ueK-gq-gaF" firstAttribute="leading" secondItem="MTh-9p-FqC" secondAttribute="trailing" constant="8" symbolic="YES" id="9m6-6j-8j2"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="Lrf-gL-6EI" secondAttribute="trailing" constant="20" symbolic="YES" id="M08-mP-Plz"/>
-                                        <constraint firstItem="ueK-gq-gaF" firstAttribute="top" secondItem="fLI-XB-QCr" secondAttribute="top" constant="5" id="XN3-GK-BX9"/>
+                                        <constraint firstItem="ueK-gq-gaF" firstAttribute="top" secondItem="fLI-XB-QCr" secondAttribute="top" constant="20" symbolic="YES" id="XN3-GK-BX9"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="ueK-gq-gaF" secondAttribute="trailing" constant="20" symbolic="YES" id="YZ9-7N-ssA"/>
                                         <constraint firstItem="MTh-9p-FqC" firstAttribute="leading" secondItem="fLI-XB-QCr" secondAttribute="leading" constant="20" symbolic="YES" id="bgZ-k9-IQC"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="2eV-Us-eEv" secondAttribute="trailing" constant="20" symbolic="YES" id="eiB-vH-17d"/>
@@ -529,18 +649,18 @@ Gw
                                         <constraint firstItem="2eV-Us-eEv" firstAttribute="leading" secondItem="gRS-DK-rIy" secondAttribute="trailing" constant="8" symbolic="YES" id="hQ9-uy-KHg"/>
                                         <constraint firstItem="gRS-DK-rIy" firstAttribute="leading" secondItem="fLI-XB-QCr" secondAttribute="leading" constant="20" symbolic="YES" id="iyp-1K-rdC"/>
                                         <constraint firstItem="gRS-DK-rIy" firstAttribute="centerY" secondItem="2eV-Us-eEv" secondAttribute="centerY" id="qWf-Nb-PfJ"/>
-                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="Lrf-gL-6EI" secondAttribute="bottom" constant="3" id="vNb-Sw-Mxw"/>
+                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="Lrf-gL-6EI" secondAttribute="bottom" constant="20" symbolic="YES" id="vNb-Sw-Mxw"/>
                                         <constraint firstItem="Lrf-gL-6EI" firstAttribute="top" secondItem="2eV-Us-eEv" secondAttribute="bottom" constant="8" symbolic="YES" id="zBX-Qq-j5f"/>
                                     </constraints>
                                 </view>
                             </tabViewItem>
                             <tabViewItem label="ZX80" identifier="zx80" id="tMH-kF-GUz">
                                 <view key="view" id="8hL-Vn-Hg0">
-                                    <rect key="frame" x="10" y="7" width="400" height="76"/>
+                                    <rect key="frame" x="10" y="7" width="400" height="223"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="I1a-Eu-5UB">
-                                            <rect key="frame" x="108" y="47" width="116" height="25"/>
+                                            <rect key="frame" x="108" y="179" width="116" height="25"/>
                                             <popUpButtonCell key="cell" type="push" title="Unexpanded" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" imageScaling="axesIndependently" inset="2" selectedItem="4Sa-jR-xOd" id="B8M-do-Yod">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
@@ -554,7 +674,7 @@ Gw
                                             </popUpButtonCell>
                                         </popUpButton>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="NCX-4e-lSu">
-                                            <rect key="frame" x="18" y="53" width="87" height="16"/>
+                                            <rect key="frame" x="18" y="185" width="87" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Memory Size:" id="e6x-TE-OC5">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -562,7 +682,7 @@ Gw
                                             </textFieldCell>
                                         </textField>
                                         <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="ReP-bV-Thu">
-                                            <rect key="frame" x="18" y="26" width="118" height="18"/>
+                                            <rect key="frame" x="18" y="158" width="118" height="18"/>
                                             <buttonCell key="cell" type="check" title="Use ZX81 ROM" bezelStyle="regularSquare" imagePosition="left" state="on" inset="2" id="VQH-nv-Pfm">
                                                 <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
                                                 <font key="font" metaFont="system"/>
@@ -574,8 +694,8 @@ Gw
                                         <constraint firstItem="NCX-4e-lSu" firstAttribute="centerY" secondItem="I1a-Eu-5UB" secondAttribute="centerY" id="1ve-sc-QwI"/>
                                         <constraint firstItem="I1a-Eu-5UB" firstAttribute="leading" secondItem="NCX-4e-lSu" secondAttribute="trailing" constant="8" symbolic="YES" id="Bu6-60-74x"/>
                                         <constraint firstItem="NCX-4e-lSu" firstAttribute="leading" secondItem="8hL-Vn-Hg0" secondAttribute="leading" constant="20" symbolic="YES" id="W09-iG-ARI"/>
-                                        <constraint firstItem="I1a-Eu-5UB" firstAttribute="top" secondItem="8hL-Vn-Hg0" secondAttribute="top" constant="5" id="fkf-wO-Q8i"/>
-                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="ReP-bV-Thu" secondAttribute="bottom" constant="3" id="fmT-7E-hUT"/>
+                                        <constraint firstItem="I1a-Eu-5UB" firstAttribute="top" secondItem="8hL-Vn-Hg0" secondAttribute="top" constant="20" symbolic="YES" id="fkf-wO-Q8i"/>
+                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="ReP-bV-Thu" secondAttribute="bottom" constant="20" symbolic="YES" id="fmT-7E-hUT"/>
                                         <constraint firstItem="ReP-bV-Thu" firstAttribute="top" secondItem="I1a-Eu-5UB" secondAttribute="bottom" constant="8" symbolic="YES" id="hYk-xC-63o"/>
                                         <constraint firstItem="ReP-bV-Thu" firstAttribute="leading" secondItem="8hL-Vn-Hg0" secondAttribute="leading" constant="20" symbolic="YES" id="qen-KS-rWi"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="ReP-bV-Thu" secondAttribute="trailing" constant="20" symbolic="YES" id="r7F-DT-oRc"/>
@@ -584,11 +704,11 @@ Gw
                             </tabViewItem>
                             <tabViewItem label="ZX81" identifier="zx81" id="Wnn-nQ-gZ6">
                                 <view key="view" id="bmd-gL-gzT">
-                                    <rect key="frame" x="10" y="7" width="400" height="186"/>
+                                    <rect key="frame" x="10" y="7" width="400" height="223"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="5aO-UX-HnX">
-                                            <rect key="frame" x="108" y="157" width="116" height="25"/>
+                                            <rect key="frame" x="108" y="179" width="116" height="25"/>
                                             <popUpButtonCell key="cell" type="push" title="Unexpanded" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" imageScaling="axesIndependently" inset="2" selectedItem="7QC-Ij-hES" id="d3W-Gl-3Mf">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
@@ -602,7 +722,7 @@ Gw
                                             </popUpButtonCell>
                                         </popUpButton>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="8tU-73-XEE">
-                                            <rect key="frame" x="18" y="163" width="87" height="16"/>
+                                            <rect key="frame" x="18" y="185" width="87" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Memory Size:" id="z4b-oR-Yl2">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -613,37 +733,37 @@ Gw
                                     <constraints>
                                         <constraint firstItem="8tU-73-XEE" firstAttribute="centerY" secondItem="5aO-UX-HnX" secondAttribute="centerY" id="1Jm-YL-OKU"/>
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="5aO-UX-HnX" secondAttribute="trailing" constant="20" symbolic="YES" id="ALj-0x-bFb"/>
-                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="5aO-UX-HnX" secondAttribute="bottom" constant="5" id="LJ2-W9-fOf"/>
+                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="5aO-UX-HnX" secondAttribute="bottom" constant="20" symbolic="YES" id="LJ2-W9-fOf"/>
                                         <constraint firstItem="8tU-73-XEE" firstAttribute="leading" secondItem="bmd-gL-gzT" secondAttribute="leading" constant="20" symbolic="YES" id="M6Y-jN-LAf"/>
-                                        <constraint firstItem="5aO-UX-HnX" firstAttribute="top" secondItem="bmd-gL-gzT" secondAttribute="top" constant="5" id="PPD-Jz-qCL"/>
+                                        <constraint firstItem="5aO-UX-HnX" firstAttribute="top" secondItem="bmd-gL-gzT" secondAttribute="top" constant="20" symbolic="YES" id="PPD-Jz-qCL"/>
                                         <constraint firstItem="5aO-UX-HnX" firstAttribute="leading" secondItem="8tU-73-XEE" secondAttribute="trailing" constant="8" symbolic="YES" id="j1u-n4-2IK"/>
                                     </constraints>
                                 </view>
                             </tabViewItem>
                             <tabViewItem label="ZX Spectrum" identifier="spectrum" id="HQv-oF-k8b">
                                 <view key="view" id="bMx-F6-JUb">
-                                    <rect key="frame" x="10" y="7" width="400" height="186"/>
+                                    <rect key="frame" x="10" y="7" width="400" height="223"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
                                         <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="gFZ-d4-WFv">
-                                            <rect key="frame" x="67" y="157" width="76" height="25"/>
-                                            <popUpButtonCell key="cell" type="push" title="16kb" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" borderStyle="borderAndBezel" tag="16" imageScaling="axesIndependently" inset="2" selectedItem="Fo7-NL-Kv5" id="tYs-sA-oek">
+                                            <rect key="frame" x="67" y="179" width="76" height="25"/>
+                                            <popUpButtonCell key="cell" type="push" title="16kb" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" tag="16" imageScaling="axesIndependently" inset="2" selectedItem="Fo7-NL-Kv5" id="tYs-sA-oek">
                                                 <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                                                 <font key="font" metaFont="menu"/>
                                                 <menu key="menu" id="8lt-dk-zPr">
                                                     <items>
-                                                        <menuItem title="16kb" tag="16" id="Fo7-NL-Kv5"/>
+                                                        <menuItem title="16kb" state="on" tag="16" id="Fo7-NL-Kv5"/>
                                                         <menuItem title="48kb" tag="48" id="xks-Rv-Umd"/>
                                                         <menuItem title="128kb" tag="128" id="w8h-lY-JLX"/>
                                                         <menuItem title="+2" tag="2" id="Vvu-ua-pjg"/>
-                                                        <menuItem title="+2a" state="on" tag="21" id="bFk-nC-Txe"/>
+                                                        <menuItem title="+2a" tag="21" id="bFk-nC-Txe"/>
                                                         <menuItem title="+3" tag="3" id="jwx-fZ-vXp"/>
                                                     </items>
                                                 </menu>
                                             </popUpButtonCell>
                                         </popUpButton>
                                         <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="fJ3-ma-Byy">
-                                            <rect key="frame" x="18" y="163" width="46" height="16"/>
+                                            <rect key="frame" x="18" y="185" width="46" height="16"/>
                                             <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="Model:" id="JId-Tp-LrE">
                                                 <font key="font" metaFont="system"/>
                                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -655,23 +775,23 @@ Gw
                                         <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="gFZ-d4-WFv" secondAttribute="trailing" constant="20" symbolic="YES" id="90E-uI-MQg"/>
                                         <constraint firstItem="fJ3-ma-Byy" firstAttribute="leading" secondItem="bMx-F6-JUb" secondAttribute="leading" constant="20" symbolic="YES" id="9kE-iQ-dxd"/>
                                         <constraint firstItem="fJ3-ma-Byy" firstAttribute="centerY" secondItem="gFZ-d4-WFv" secondAttribute="centerY" id="LxG-5E-Q5Y"/>
-                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="gFZ-d4-WFv" secondAttribute="bottom" constant="5" id="d8S-vX-B5e"/>
+                                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="gFZ-d4-WFv" secondAttribute="bottom" constant="20" symbolic="YES" id="d8S-vX-B5e"/>
                                         <constraint firstItem="gFZ-d4-WFv" firstAttribute="leading" secondItem="fJ3-ma-Byy" secondAttribute="trailing" constant="8" symbolic="YES" id="hKS-47-R2y"/>
-                                        <constraint firstItem="gFZ-d4-WFv" firstAttribute="top" secondItem="bMx-F6-JUb" secondAttribute="top" constant="5" id="wsX-Wq-iPt"/>
+                                        <constraint firstItem="gFZ-d4-WFv" firstAttribute="top" secondItem="bMx-F6-JUb" secondAttribute="top" constant="20" symbolic="YES" id="wsX-Wq-iPt"/>
                                     </constraints>
                                 </view>
                             </tabViewItem>
                         </tabViewItems>
                     </tabView>
                     <scrollView borderType="line" autohidesScrollers="YES" horizontalLineScroll="24" horizontalPageScroll="10" verticalLineScroll="24" verticalPageScroll="10" hasHorizontalScroller="NO" usesPredominantAxisScrolling="NO" id="z5Q-Bs-hJj">
-                        <rect key="frame" x="20" y="60" width="130" height="201"/>
+                        <rect key="frame" x="20" y="60" width="130" height="238"/>
                         <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" heightSizable="YES"/>
                         <clipView key="contentView" id="O8s-Vw-9yQ">
-                            <rect key="frame" x="1" y="1" width="128" height="199"/>
+                            <rect key="frame" x="1" y="1" width="128" height="236"/>
                             <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                             <subviews>
                                 <tableView verticalHuggingPriority="750" allowsExpansionToolTips="YES" columnAutoresizingStyle="none" columnReordering="NO" columnResizing="NO" multipleSelection="NO" emptySelection="NO" autosaveColumns="NO" typeSelect="NO" rowHeight="24" id="3go-Eb-GOy">
-                                    <rect key="frame" x="0.0" y="0.0" width="128" height="199"/>
+                                    <rect key="frame" x="0.0" y="0.0" width="128" height="236"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <size key="intercellSpacing" width="17" height="0.0"/>
                                     <color key="backgroundColor" name="controlBackgroundColor" catalog="System" colorSpace="catalog"/>
@@ -708,7 +828,7 @@ Gw
                         </scroller>
                     </scrollView>
                     <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="VAc-6N-O7q">
-                        <rect key="frame" x="18" y="269" width="554" height="27"/>
+                        <rect key="frame" x="18" y="306" width="554" height="27"/>
                         <textFieldCell key="cell" lineBreakMode="clipping" title="Choose a machine" id="32m-Vs-dPO">
                             <font key="font" textStyle="title2" name=".SFNS-Regular"/>
                             <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -737,7 +857,7 @@ Gw
                     <constraint firstItem="9YM-5x-pc0" firstAttribute="top" secondItem="z5Q-Bs-hJj" secondAttribute="bottom" constant="14" id="suf-rn-Bmy"/>
                 </constraints>
             </view>
-            <point key="canvasLocation" x="-1" y="88"/>
+            <point key="canvasLocation" x="-1" y="106.5"/>
         </window>
         <customObject id="192-Eb-Rpg" customClass="MachinePicker" customModule="Clock_Signal" customModuleProvider="target">
             <connections>
@@ -750,6 +870,10 @@ Gw
                 <outlet property="electronAP6Button" destination="cG2-Ph-S3Z" id="vkq-1J-KBG"/>
                 <outlet property="electronDFSButton" destination="JqM-IK-FMP" id="C80-1k-TdQ"/>
                 <outlet property="electronSidewaysRAMButton" destination="lzo-8g-o4S" id="LtS-wv-tMf"/>
+                <outlet property="enterpriseBASICButton" destination="hIr-GH-7xi" id="fM6-It-9UO"/>
+                <outlet property="enterpriseDOSButton" destination="syE-e7-TjU" id="sCW-Bj-ZTW"/>
+                <outlet property="enterpriseEXOSButton" destination="nen-Za-7zH" id="NwS-ua-FdA"/>
+                <outlet property="enterpriseModelButton" destination="PhH-bu-pb5" id="8wD-sW-aBw"/>
                 <outlet property="machineNameTable" destination="3go-Eb-GOy" id="Ppf-S0-IP1"/>
                 <outlet property="machineSelector" destination="VUb-QG-x7c" id="crR-hB-jGd"/>
                 <outlet property="macintoshModelTypeButton" destination="xa6-NA-JY5" id="2jX-PY-v2z"/>

OSBindings/Mac/Clock Signal/MachinePicker/MachinePicker.swift

@@ -27,14 +27,20 @@ class MachinePicker: NSObject, NSTableViewDataSource, NSTableViewDelegate {
 	@IBOutlet var appleIIgsModelButton: NSPopUpButton!
 	@IBOutlet var appleIIgsMemorySizeButton: NSPopUpButton!
 
+	// MARK: - CPC properties
+	@IBOutlet var cpcModelTypeButton: NSPopUpButton!
+
 	// MARK: - Electron properties
 	@IBOutlet var electronDFSButton: NSButton!
 	@IBOutlet var electronADFSButton: NSButton!
 	@IBOutlet var electronAP6Button: NSButton!
 	@IBOutlet var electronSidewaysRAMButton: NSButton!
 
-	// MARK: - CPC properties
-	@IBOutlet var cpcModelTypeButton: NSPopUpButton!
+	// MARK: - Enterprise properties
+	@IBOutlet var enterpriseModelButton: NSPopUpButton!
+	@IBOutlet var enterpriseEXOSButton: NSPopUpButton!
+	@IBOutlet var enterpriseBASICButton: NSPopUpButton!
+	@IBOutlet var enterpriseDOSButton: NSPopUpButton!
 
 	// MARK: - Macintosh properties
 	@IBOutlet var macintoshModelTypeButton: NSPopUpButton!
@@ -93,14 +99,20 @@ class MachinePicker: NSObject, NSTableViewDataSource, NSTableViewDelegate {
 		appleIIgsModelButton.selectItem(withTag: standardUserDefaults.integer(forKey: "new.appleIIgsModel"))
 		appleIIgsMemorySizeButton.selectItem(withTag: standardUserDefaults.integer(forKey: "new.appleIIgsMemorySize"))
 
+		// CPC settings
+		cpcModelTypeButton.selectItem(withTag: standardUserDefaults.integer(forKey: "new.cpcModel"))
+
 		// Electron settings
 		electronDFSButton.state = standardUserDefaults.bool(forKey: "new.electronDFS") ? .on : .off
 		electronADFSButton.state = standardUserDefaults.bool(forKey: "new.electronADFS") ? .on : .off
 		electronAP6Button.state = standardUserDefaults.bool(forKey: "new.electronAP6") ? .on : .off
 		electronSidewaysRAMButton.state = standardUserDefaults.bool(forKey: "new.electronSidewaysRAM") ? .on : .off
 
-		// CPC settings
-		cpcModelTypeButton.selectItem(withTag: standardUserDefaults.integer(forKey: "new.cpcModel"))
+		// Enterprise settings
+		enterpriseModelButton.selectItem(withTag: standardUserDefaults.integer(forKey: "new.enterpriseModel"))
+		enterpriseEXOSButton.selectItem(withTag: standardUserDefaults.integer(forKey: "new.enterpriseEXOSVersion"))
+		enterpriseBASICButton.selectItem(withTag: standardUserDefaults.integer(forKey: "new.enterpriseBASICVersion"))
+		enterpriseDOSButton.selectItem(withTag: standardUserDefaults.integer(forKey: "new.enterpriseDOS"))
 
 		// Macintosh settings
 		macintoshModelTypeButton.selectItem(withTag: standardUserDefaults.integer(forKey: "new.macintoshModel"))
@@ -143,14 +155,20 @@ class MachinePicker: NSObject, NSTableViewDataSource, NSTableViewDelegate {
 		standardUserDefaults.set(appleIIgsModelButton.selectedTag(), forKey: "new.appleIIgsModel")
 		standardUserDefaults.set(appleIIgsMemorySizeButton.selectedTag(), forKey: "new.appleIIgsMemorySize")
 
+		// CPC settings
+		standardUserDefaults.set(cpcModelTypeButton.selectedTag(), forKey: "new.cpcModel")
+
 		// Electron settings
 		standardUserDefaults.set(electronDFSButton.state == .on, forKey: "new.electronDFS")
 		standardUserDefaults.set(electronADFSButton.state == .on, forKey: "new.electronADFS")
 		standardUserDefaults.set(electronAP6Button.state == .on, forKey: "new.electronAP6")
 		standardUserDefaults.set(electronSidewaysRAMButton.state == .on, forKey: "new.electronSidewaysRAM")
 
-		// CPC settings
-		standardUserDefaults.set(cpcModelTypeButton.selectedTag(), forKey: "new.cpcModel")
+		// Enterprise settings
+		standardUserDefaults.set(enterpriseModelButton.selectedTag(), forKey: "new.enterpriseModel")
+		standardUserDefaults.set(enterpriseEXOSButton.selectedTag(), forKey: "new.enterpriseEXOSVersion")
+		standardUserDefaults.set(enterpriseBASICButton.selectedTag(), forKey: "new.enterpriseBASICVersion")
+		standardUserDefaults.set(enterpriseDOSButton.selectedTag(), forKey: "new.enterpriseDOS")
 
 		// Macintosh settings
 		standardUserDefaults.set(macintoshModelTypeButton.selectedTag(), forKey: "new.macintoshModel")
@@ -205,12 +223,6 @@ class MachinePicker: NSObject, NSTableViewDataSource, NSTableViewDelegate {
 		storeOptions()
 
 		switch machineSelector.selectedTabViewItem!.identifier as! String {
-			case "electron":
-				return CSStaticAnalyser(
-					electronDFS: electronDFSButton.state == .on,
-					adfs: electronADFSButton.state == .on,
-					ap6: electronAP6Button.state == .on,
-					sidewaysRAM: electronSidewaysRAMButton.state == .on)
 
 			case "appleii":
 				var model: CSMachineAppleIIModel = .appleII
@@ -255,6 +267,48 @@ class MachinePicker: NSObject, NSTableViewDataSource, NSTableViewDelegate {
 					default:	return CSStaticAnalyser(amstradCPCModel: .model6128)
 				}
 
+			case "electron":
+				return CSStaticAnalyser(
+					electronDFS: electronDFSButton.state == .on,
+					adfs: electronADFSButton.state == .on,
+					ap6: electronAP6Button.state == .on,
+					sidewaysRAM: electronSidewaysRAMButton.state == .on)
+
+			case "enterprise":
+				var model: CSMachineEnterpriseModel = .model128
+				switch enterpriseModelButton.selectedItem!.tag {
+					case 64:	model = .model64
+					case 256:	model = .model256
+					case 128:	fallthrough
+					default:	model = .model128
+				}
+
+				var exos: CSMachineEnterpriseEXOS = .version21
+				switch enterpriseEXOSButton.selectedItem!.tag {
+					case 10:	exos = .version10
+					case 20:	exos = .version20
+					case 21:	fallthrough
+					default:	exos = .version21
+				}
+
+				var basic: CSMachineEnterpriseBASIC = .version21
+				switch enterpriseBASICButton.selectedTag() {
+					case 0:		basic = .none
+					case 10:	basic = .version10
+					case 11:	basic = .version11
+					case 21:	fallthrough
+					default:	basic = .version21
+				}
+
+				var dos: CSMachineEnterpriseDOS = .dosNone
+				switch enterpriseDOSButton.selectedTag() {
+					case 1:		dos = .DOSEXDOS
+					case 0:		fallthrough
+					default:	dos = .dosNone
+				}
+
+				return CSStaticAnalyser(enterpriseModel: model, exosVersion: exos, basicVersion: basic, dos: dos)
+
 			case "mac":
 				switch macintoshModelTypeButton.selectedItem!.tag {
 					case 0:		return CSStaticAnalyser(macintoshModel: .model128k)

OSBindings/Mac/Clock Signal/ROMRequester/ROMRequester.xib

@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="17506" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="18122" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
     <dependencies>
         <deployment identifier="macosx"/>
-        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="17506"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="18122"/>
         <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
     </dependencies>
     <objects>
@@ -20,18 +20,16 @@
             <windowStyleMask key="styleMask" titled="YES"/>
             <windowPositionMask key="initialPositionMask" leftStrut="YES" rightStrut="YES" topStrut="YES" bottomStrut="YES"/>
             <rect key="contentRect" x="196" y="240" width="480" height="270"/>
-            <rect key="screenRect" x="0.0" y="0.0" width="1440" height="900"/>
+            <rect key="screenRect" x="0.0" y="0.0" width="2560" height="1440"/>
             <view key="contentView" wantsLayer="YES" id="EiT-Mj-1SZ" customClass="CSROMReceiverView">
                 <rect key="frame" x="0.0" y="0.0" width="480" height="270"/>
                 <autoresizingMask key="autoresizingMask"/>
                 <subviews>
                     <textField verticalHuggingPriority="750" horizontalCompressionResistancePriority="250" setsMaxLayoutWidthAtFirstLayout="YES" textCompletion="NO" translatesAutoresizingMaskIntoConstraints="NO" id="5qG-I3-Qav">
-                        <rect key="frame" x="18" y="154" width="444" height="96"/>
+                        <rect key="frame" x="18" y="186" width="444" height="64"/>
                         <textFieldCell key="cell" enabled="NO" allowsUndo="NO" id="itJ-2T-0ia">
                             <font key="font" usesAppearanceFont="YES"/>
-                            <string key="title">Clock Signal requires you to provide images of the system ROMs for this machine. They will be stored permanently; you need do this only once.

Please drag and drop the following over this text:
-
-</string>
+                            <string key="title">Clock Signal requires you to provide images of the system ROMs for this machine. They will be stored permanently; you need do this only once.

Please drag and drop over this text</string>
                             <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
                             <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
                         </textFieldCell>

OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.h

@@ -22,4 +22,6 @@
 
 - (nonnull NSBitmapImageRep *)imageRepresentation;
 
+- (void)willChangeOwner;
+
 @end