Merge pull request #855 from TomHarte/QtNoKeyboardCopy

Qt: don't copy the result of get_keyboard().

.github/workflows/ccpp.yml

@@ -0,0 +1,16 @@
+name: SDL/Ubuntu
+
+on: [push, pull_request]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Install dependencies
+      run: sudo apt-get --allow-releaseinfo-change update && sudo apt-get --fix-missing install libsdl2-dev scons
+    - name: Make
+      working-directory: OSBindings/SDL
+      run: scons -j$(nproc --all)

.travis.yml

@@ -1,13 +0,0 @@
-# language: objective-c
-# osx_image: xcode8.2
-# xcode_project: OSBindings/Mac/Clock Signal.xcodeproj
-# xcode_scheme: Clock Signal
-# xcode_sdk: macosx10.12
-
-language: cpp
-before_install:
-	- sudo apt-get install libsdl2-dev
-script: cd OSBindings/SDL && scons
-compiler:
-	- clang
-	- gcc

Activity/Observer.hpp

@@ -24,13 +24,13 @@ namespace Activity {
 class Observer {
 	public:
 		/// Announces to the receiver that there is an LED of name @c name.
-		virtual void register_led(const std::string &name) {}
+		virtual void register_led([[maybe_unused]] const std::string &name) {}
 
 		/// Announces to the receiver that there is a drive of name @c name.
-		virtual void register_drive(const std::string &name) {}
+		virtual void register_drive([[maybe_unused]] const std::string &name) {}
 
 		/// Informs the receiver of the new state of the LED with name @c name.
-		virtual void set_led_status(const std::string &name, bool lit) {}
+		virtual void set_led_status([[maybe_unused]] const std::string &name, [[maybe_unused]] bool lit) {}
 
 		enum class DriveEvent {
 			StepNormal,
@@ -39,10 +39,10 @@ class Observer {
 		};
 
 		/// Informs the receiver that the named event just occurred for the drive with name @c name.
-		virtual void announce_drive_event(const std::string &name, DriveEvent event) {}
+		virtual void announce_drive_event([[maybe_unused]] const std::string &name, [[maybe_unused]] DriveEvent event) {}
 
 		/// Informs the receiver of the motor-on status of the drive with name @c name.
-		virtual void set_drive_motor_status(const std::string &name, bool is_on) {}
+		virtual void set_drive_motor_status([[maybe_unused]] const std::string &name, [[maybe_unused]] bool is_on) {}
 };
 
 }

Analyser/Dynamic/ConfidenceCounter.cpp

@@ -11,20 +11,20 @@
 using namespace Analyser::Dynamic;
 
 float ConfidenceCounter::get_confidence() {
-	return static_cast<float>(hits_) / static_cast<float>(hits_ + misses_);
+	return float(hits_) / float(hits_ + misses_);
 }
 
 void ConfidenceCounter::add_hit() {
-	hits_++;
+	++hits_;
 }
 
 void ConfidenceCounter::add_miss() {
-	misses_++;
+	++misses_;
 }
 
 void ConfidenceCounter::add_equivocal() {
 	if(hits_ > misses_) {
-		hits_++;
-		misses_++;
+		++hits_;
+		++misses_;
 	}
 }

Analyser/Dynamic/ConfidenceCounter.hpp

@@ -22,7 +22,7 @@ namespace Dynamic {
 class ConfidenceCounter: public ConfidenceSource {
 	public:
 		/*! @returns The computed probability, based on the history of events. */
-		float get_confidence() override;
+		float get_confidence() final;
 
 		/*! Records an event that implies this is the appropriate class: pushes probability up towards 1.0. */
 		void add_hit();

Analyser/Dynamic/ConfidenceSummary.hpp

@@ -32,11 +32,11 @@ class ConfidenceSummary: public ConfidenceSource {
 			const std::vector<float> &weights);
 
 		/*! @returns The weighted sum of all sources. */
-		float get_confidence() override;
+		float get_confidence() final;
 
 	private:
-		std::vector<ConfidenceSource *> sources_;
-		std::vector<float> weights_;
+		const std::vector<ConfidenceSource *> sources_;
+		const std::vector<float> weights_;
 		float weight_sum_;
 };
 

Analyser/Dynamic/MultiMachine/Implementation/MultiCRTMachine.cpp

@@ -1,87 +0,0 @@
-//
-//  MultiCRTMachine.cpp
-//  Clock Signal
-//
-//  Created by Thomas Harte on 29/01/2018.
-//  Copyright 2018 Thomas Harte. All rights reserved.
-//
-
-#include "MultiCRTMachine.hpp"
-
-#include <condition_variable>
-#include <mutex>
-
-using namespace Analyser::Dynamic;
-
-MultiCRTMachine::MultiCRTMachine(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines, std::recursive_mutex &machines_mutex) :
-	machines_(machines), machines_mutex_(machines_mutex), queues_(machines.size()) {
-	speaker_ = MultiSpeaker::create(machines);
-}
-
-void MultiCRTMachine::perform_parallel(const std::function<void(::CRTMachine::Machine *)> &function) {
-	// Apply a blunt force parallelisation of the machines; each run_for is dispatched
-	// to a separate queue and this queue will block until all are done.
-	volatile std::size_t outstanding_machines;
-	std::condition_variable condition;
-	std::mutex mutex;
-	{
-		std::lock_guard<decltype(machines_mutex_)> machines_lock(machines_mutex_);
-		std::lock_guard<std::mutex> lock(mutex);
-		outstanding_machines = machines_.size();
-
-		for(std::size_t index = 0; index < machines_.size(); ++index) {
-			CRTMachine::Machine *crt_machine = machines_[index]->crt_machine();
-			queues_[index].enqueue([&mutex, &condition, crt_machine, function, &outstanding_machines]() {
-				if(crt_machine) function(crt_machine);
-
-				std::lock_guard<std::mutex> lock(mutex);
-				outstanding_machines--;
-				condition.notify_all();
-			});
-		}
-	}
-
-	std::unique_lock<std::mutex> lock(mutex);
-	condition.wait(lock, [&outstanding_machines] { return !outstanding_machines; });
-}
-
-void MultiCRTMachine::perform_serial(const std::function<void (::CRTMachine::Machine *)> &function) {
-	std::lock_guard<decltype(machines_mutex_)> machines_lock(machines_mutex_);
-	for(const auto &machine: machines_) {
-		CRTMachine::Machine *const crt_machine = machine->crt_machine();
-		if(crt_machine) function(crt_machine);
-	}
-}
-
-void MultiCRTMachine::set_scan_target(Outputs::Display::ScanTarget *scan_target) {
-	scan_target_ = scan_target;
-
-	CRTMachine::Machine *const crt_machine = machines_.front()->crt_machine();
-	if(crt_machine) crt_machine->set_scan_target(scan_target);
-}
-
-Outputs::Speaker::Speaker *MultiCRTMachine::get_speaker() {
-	return speaker_;
-}
-
-void MultiCRTMachine::run_for(Time::Seconds duration) {
-	perform_parallel([=](::CRTMachine::Machine *machine) {
-		if(machine->get_confidence() >= 0.01f) machine->run_for(duration);
-	});
-
-	if(delegate_) delegate_->multi_crt_did_run_machines();
-}
-
-void MultiCRTMachine::did_change_machine_order() {
-	if(scan_target_) scan_target_->will_change_owner();
-
-	perform_serial([=](::CRTMachine::Machine *machine) {
-		machine->set_scan_target(nullptr);
-	});
-	CRTMachine::Machine *const crt_machine = machines_.front()->crt_machine();
-	if(crt_machine) crt_machine->set_scan_target(scan_target_);
-
-	if(speaker_) {
-		speaker_->set_new_front_machine(machines_.front().get());
-	}
-}

Analyser/Dynamic/MultiMachine/Implementation/MultiConfigurable.cpp

@@ -12,6 +12,97 @@
 
 using namespace Analyser::Dynamic;
 
+namespace {
+
+class MultiStruct: public Reflection::Struct {
+	public:
+		MultiStruct(const std::vector<Configurable::Device *> &devices) : devices_(devices) {
+			for(auto device: devices) {
+				options_.emplace_back(device->get_options());
+			}
+		}
+
+		void apply() {
+			auto options = options_.begin();
+			for(auto device: devices_) {
+				device->set_options(*options);
+				++options;
+			}
+		}
+
+		std::vector<std::string> all_keys() const final {
+			std::set<std::string> keys;
+			for(auto &options: options_) {
+				const auto new_keys = options->all_keys();
+				keys.insert(new_keys.begin(), new_keys.end());
+			}
+			return std::vector<std::string>(keys.begin(), keys.end());
+		}
+
+		std::vector<std::string> values_for(const std::string &name) const final {
+			std::set<std::string> values;
+			for(auto &options: options_) {
+				const auto new_values = options->values_for(name);
+				values.insert(new_values.begin(), new_values.end());
+			}
+			return std::vector<std::string>(values.begin(), values.end());
+		}
+
+		const std::type_info *type_of(const std::string &name) const final {
+			for(auto &options: options_) {
+				auto info = options->type_of(name);
+				if(info) return info;
+			}
+			return nullptr;
+		}
+
+		size_t count_of(const std::string &name) const final {
+			for(auto &options: options_) {
+				auto info = options->type_of(name);
+				if(info) return options->count_of(name);
+			}
+			return 0;
+		}
+
+		const void *get(const std::string &name) const final {
+			for(auto &options: options_) {
+				auto value = options->get(name);
+				if(value) return value;
+			}
+			return nullptr;
+		}
+
+		void *get(const std::string &name) final {
+			for(auto &options: options_) {
+				auto value = options->get(name);
+				if(value) return value;
+			}
+			return nullptr;
+		}
+
+		void set(const std::string &name, const void *value, size_t offset) final {
+			const auto safe_type = type_of(name);
+			if(!safe_type) return;
+
+			// Set this property only where the child's type is the same as that
+			// which was returned from here for type_of.
+			for(auto &options: options_) {
+				const auto type = options->type_of(name);
+				if(!type) continue;
+
+				if(*type == *safe_type) {
+					options->set(name, value, offset);
+				}
+			}
+		}
+
+	private:
+		const std::vector<Configurable::Device *> &devices_;
+		std::vector<std::unique_ptr<Reflection::Struct>> options_;
+};
+
+}
+
 MultiConfigurable::MultiConfigurable(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines) {
 	for(const auto &machine: machines) {
 		Configurable::Device *device = machine->configurable_device();
@@ -19,46 +110,11 @@ MultiConfigurable::MultiConfigurable(const std::vector<std::unique_ptr<::Machine
 	}
 }
 
-std::vector<std::unique_ptr<Configurable::Option>> MultiConfigurable::get_options() {
-	std::vector<std::unique_ptr<Configurable::Option>> options;
-
-	// Produce the list of unique options.
-	for(const auto &device : devices_) {
-		std::vector<std::unique_ptr<Configurable::Option>> device_options = device->get_options();
-		for(auto &option : device_options) {
-			if(std::find(options.begin(), options.end(), option) == options.end()) {
-				options.push_back(std::move(option));
-			}
-		}
-	}
-
-	return options;
+void MultiConfigurable::set_options(const std::unique_ptr<Reflection::Struct> &str) {
+	const auto options = dynamic_cast<MultiStruct *>(str.get());
+	options->apply();
 }
 
-void MultiConfigurable::set_selections(const Configurable::SelectionSet &selection_by_option) {
-	for(const auto &device : devices_) {
-		device->set_selections(selection_by_option);
-	}
-}
-
-Configurable::SelectionSet MultiConfigurable::get_accurate_selections() {
-	Configurable::SelectionSet set;
-	for(const auto &device : devices_) {
-		Configurable::SelectionSet device_set = device->get_accurate_selections();
-		for(auto &selection : device_set) {
-			set.insert(std::move(selection));
-		}
-	}
-	return set;
-}
-
-Configurable::SelectionSet MultiConfigurable::get_user_friendly_selections() {
-	Configurable::SelectionSet set;
-	for(const auto &device : devices_) {
-		Configurable::SelectionSet device_set = device->get_user_friendly_selections();
-		for(auto &selection : device_set) {
-			set.insert(std::move(selection));
-		}
-	}
-	return set;
+std::unique_ptr<Reflection::Struct> MultiConfigurable::get_options() {
+	return std::make_unique<MultiStruct>(devices_);
 }

Analyser/Dynamic/MultiMachine/Implementation/MultiConfigurable.hpp

@@ -10,6 +10,7 @@
 #define MultiConfigurable_hpp
 
 #include "../../../../Machines/DynamicMachine.hpp"
+#include "../../../../Configurable/Configurable.hpp"
 
 #include <memory>
 #include <vector>
@@ -28,10 +29,8 @@ class MultiConfigurable: public Configurable::Device {
 		MultiConfigurable(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines);
 
 		// Below is the standard Configurable::Device interface; see there for documentation.
-		std::vector<std::unique_ptr<Configurable::Option>> get_options() override;
-		void set_selections(const Configurable::SelectionSet &selection_by_option) override;
-		Configurable::SelectionSet get_accurate_selections() override;
-		Configurable::SelectionSet get_user_friendly_selections() override;
+		void set_options(const std::unique_ptr<Reflection::Struct> &options) final;
+		std::unique_ptr<Reflection::Struct> get_options() final;
 
 	private:
 		std::vector<Configurable::Device *> devices_;

Analyser/Dynamic/MultiMachine/Implementation/MultiJoystickMachine.cpp

@@ -16,7 +16,7 @@ namespace {
 
 class MultiJoystick: public Inputs::Joystick {
 	public:
-		MultiJoystick(std::vector<JoystickMachine::Machine *> &machines, std::size_t index) {
+		MultiJoystick(std::vector<MachineTypes::JoystickMachine *> &machines, std::size_t index) {
 			for(const auto &machine: machines) {
 				const auto &joysticks = machine->get_joysticks();
 				if(joysticks.size() >= index) {
@@ -25,7 +25,7 @@ class MultiJoystick: public Inputs::Joystick {
 			}
 		}
 
-		std::vector<Input> &get_inputs() override {
+		const std::vector<Input> &get_inputs() final {
 			if(inputs.empty()) {
 				for(const auto &joystick: joysticks_) {
 					std::vector<Input> joystick_inputs = joystick->get_inputs();
@@ -40,19 +40,19 @@ class MultiJoystick: public Inputs::Joystick {
 			return inputs;
 		}
 
-		void set_input(const Input &digital_input, bool is_active) override {
+		void set_input(const Input &digital_input, bool is_active) final {
 			for(const auto &joystick: joysticks_) {
 				joystick->set_input(digital_input, is_active);
 			}
 		}
 
-		void set_input(const Input &digital_input, float value) override {
+		void set_input(const Input &digital_input, float value) final {
 			for(const auto &joystick: joysticks_) {
 				joystick->set_input(digital_input, value);
 			}
 		}
 
-		void reset_all_inputs() override {
+		void reset_all_inputs() final {
 			for(const auto &joystick: joysticks_) {
 				joystick->reset_all_inputs();
 			}
@@ -67,9 +67,9 @@ class MultiJoystick: public Inputs::Joystick {
 
 MultiJoystickMachine::MultiJoystickMachine(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines) {
 	std::size_t total_joysticks = 0;
-	std::vector<JoystickMachine::Machine *> joystick_machines;
+	std::vector<MachineTypes::JoystickMachine *> joystick_machines;
 	for(const auto &machine: machines) {
-		JoystickMachine::Machine *joystick_machine = machine->joystick_machine();
+		auto joystick_machine = machine->joystick_machine();
 		if(joystick_machine) {
 			joystick_machines.push_back(joystick_machine);
 			total_joysticks = std::max(total_joysticks, joystick_machine->get_joysticks().size());
@@ -81,6 +81,6 @@ MultiJoystickMachine::MultiJoystickMachine(const std::vector<std::unique_ptr<::M
 	}
 }
 
-std::vector<std::unique_ptr<Inputs::Joystick>> &MultiJoystickMachine::get_joysticks() {
+const std::vector<std::unique_ptr<Inputs::Joystick>> &MultiJoystickMachine::get_joysticks() {
 	return joysticks_;
 }

Analyser/Dynamic/MultiMachine/Implementation/MultiJoystickMachine.hpp

@@ -23,12 +23,12 @@ namespace Dynamic {
 	Makes a static internal copy of the list of machines; makes no guarantees about the
 	order of delivered messages.
 */
-class MultiJoystickMachine: public JoystickMachine::Machine {
+class MultiJoystickMachine: public MachineTypes::JoystickMachine {
 	public:
 		MultiJoystickMachine(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines);
 
 		// Below is the standard JoystickMachine::Machine interface; see there for documentation.
-		std::vector<std::unique_ptr<Inputs::Joystick>> &get_joysticks() override;
+		const std::vector<std::unique_ptr<Inputs::Joystick>> &get_joysticks() final;
 
 	private:
 		std::vector<std::unique_ptr<Inputs::Joystick>> joysticks_;

Analyser/Dynamic/MultiMachine/Implementation/MultiKeyboardMachine.cpp

@@ -10,12 +10,12 @@
 
 using namespace Analyser::Dynamic;
 
-MultiKeyboardMachine::MultiKeyboardMachine(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines) :
-	keyboard_(machines_) {
+MultiKeyboardMachine::MultiKeyboardMachine(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines) {
 	for(const auto &machine: machines) {
-		KeyboardMachine::Machine *keyboard_machine = machine->keyboard_machine();
+		auto keyboard_machine = machine->keyboard_machine();
 		if(keyboard_machine) machines_.push_back(keyboard_machine);
 	}
+	keyboard_ = std::make_unique<MultiKeyboard>(machines_);
 }
 
 void MultiKeyboardMachine::clear_all_keys() {
@@ -36,11 +36,19 @@ void MultiKeyboardMachine::type_string(const std::string &string) {
 	}
 }
 
-Inputs::Keyboard &MultiKeyboardMachine::get_keyboard() {
-	return keyboard_;
+bool MultiKeyboardMachine::can_type(char c) const {
+	bool can_type = true;
+	for(const auto &machine: machines_) {
+		can_type &= machine->can_type(c);
+	}
+	return can_type;
 }
 
-MultiKeyboardMachine::MultiKeyboard::MultiKeyboard(const std::vector<::KeyboardMachine::Machine *> &machines)
+Inputs::Keyboard &MultiKeyboardMachine::get_keyboard() {
+	return *keyboard_;
+}
+
+MultiKeyboardMachine::MultiKeyboard::MultiKeyboard(const std::vector<::MachineTypes::KeyboardMachine *> &machines)
 	: machines_(machines) {
 	for(const auto &machine: machines_) {
 		observed_keys_.insert(machine->get_keyboard().observed_keys().begin(), machine->get_keyboard().observed_keys().end());
@@ -48,10 +56,12 @@ MultiKeyboardMachine::MultiKeyboard::MultiKeyboard(const std::vector<::KeyboardM
 	}
 }
 
-void MultiKeyboardMachine::MultiKeyboard::set_key_pressed(Key key, char value, bool is_pressed) {
+bool MultiKeyboardMachine::MultiKeyboard::set_key_pressed(Key key, char value, bool is_pressed) {
+	bool was_consumed = false;
 	for(const auto &machine: machines_) {
-		machine->get_keyboard().set_key_pressed(key, value, is_pressed);
+		was_consumed |= machine->get_keyboard().set_key_pressed(key, value, is_pressed);
 	}
+	return was_consumed;
 }
 
 void MultiKeyboardMachine::MultiKeyboard::reset_all_keys() {
@@ -60,10 +70,10 @@ void MultiKeyboardMachine::MultiKeyboard::reset_all_keys() {
 	}
 }
 
-const std::set<Inputs::Keyboard::Key> &MultiKeyboardMachine::MultiKeyboard::observed_keys() {
+const std::set<Inputs::Keyboard::Key> &MultiKeyboardMachine::MultiKeyboard::observed_keys() const {
 	return observed_keys_;
 }
 
-bool MultiKeyboardMachine::MultiKeyboard::is_exclusive() {
+bool MultiKeyboardMachine::MultiKeyboard::is_exclusive() const {
 	return is_exclusive_;
 }

Analyser/Dynamic/MultiMachine/Implementation/MultiKeyboardMachine.hpp

@@ -24,34 +24,35 @@ namespace Dynamic {
 	Makes a static internal copy of the list of machines; makes no guarantees about the
 	order of delivered messages.
 */
-class MultiKeyboardMachine: public KeyboardMachine::Machine {
+class MultiKeyboardMachine: public MachineTypes::KeyboardMachine {
 	private:
-		std::vector<::KeyboardMachine::Machine *> machines_;
+		std::vector<MachineTypes::KeyboardMachine *> machines_;
 
 		class MultiKeyboard: public Inputs::Keyboard {
 			public:
-				MultiKeyboard(const std::vector<::KeyboardMachine::Machine *> &machines);
+				MultiKeyboard(const std::vector<MachineTypes::KeyboardMachine *> &machines);
 
-				void set_key_pressed(Key key, char value, bool is_pressed) override;
-				void reset_all_keys() override;
-				const std::set<Key> &observed_keys() override;
-				bool is_exclusive() override;
+				bool set_key_pressed(Key key, char value, bool is_pressed) final;
+				void reset_all_keys() final;
+				const std::set<Key> &observed_keys() const final;
+				bool is_exclusive() const final;
 
 			private:
-				const std::vector<::KeyboardMachine::Machine *> &machines_;
+				const std::vector<MachineTypes::KeyboardMachine *> &machines_;
 				std::set<Key> observed_keys_;
 				bool is_exclusive_ = false;
 		};
-		MultiKeyboard keyboard_;
+		std::unique_ptr<MultiKeyboard> keyboard_;
 
 	public:
 		MultiKeyboardMachine(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines);
 
 		// Below is the standard KeyboardMachine::Machine interface; see there for documentation.
-		void clear_all_keys() override;
-		void set_key_state(uint16_t key, bool is_pressed) override;
-		void type_string(const std::string &) override;
-		Inputs::Keyboard &get_keyboard() override;
+		void clear_all_keys() final;
+		void set_key_state(uint16_t key, bool is_pressed) final;
+		void type_string(const std::string &) final;
+		bool can_type(char c) const final;
+		Inputs::Keyboard &get_keyboard() final;
 };
 
 }

Analyser/Dynamic/MultiMachine/Implementation/MultiMediaTarget.cpp

@@ -12,7 +12,7 @@ using namespace Analyser::Dynamic;
 
 MultiMediaTarget::MultiMediaTarget(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines) {
 	for(const auto &machine: machines) {
-		MediaTarget::Machine *media_target = machine->media_target();
+		auto media_target = machine->media_target();
 		if(media_target) targets_.push_back(media_target);
 	}
 }

Analyser/Dynamic/MultiMachine/Implementation/MultiMediaTarget.hpp

@@ -24,15 +24,15 @@ namespace Dynamic {
 	Makes a static internal copy of the list of machines; makes no guarantees about the
 	order of delivered messages.
 */
-struct MultiMediaTarget: public MediaTarget::Machine {
+struct MultiMediaTarget: public MachineTypes::MediaTarget {
 	public:
 		MultiMediaTarget(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines);
 
 		// Below is the standard MediaTarget::Machine interface; see there for documentation.
-		bool insert_media(const Analyser::Static::Media &media) override;
+		bool insert_media(const Analyser::Static::Media &media) final;
 
 	private:
-		std::vector<MediaTarget::Machine *> targets_;
+		std::vector<MachineTypes::MediaTarget *> targets_;
 };
 
 }

Analyser/Dynamic/MultiMachine/Implementation/MultiProducer.cpp

@@ -0,0 +1,105 @@
+//
+//  MultiProducer.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 29/01/2018.
+//  Copyright 2018 Thomas Harte. All rights reserved.
+//
+
+#include "MultiProducer.hpp"
+
+#include <condition_variable>
+#include <mutex>
+
+using namespace Analyser::Dynamic;
+
+// MARK: - MultiInterface
+
+template <typename MachineType>
+void MultiInterface<MachineType>::perform_parallel(const std::function<void(MachineType *)> &function) {
+	// Apply a blunt force parallelisation of the machines; each run_for is dispatched
+	// to a separate queue and this queue will block until all are done.
+	volatile std::size_t outstanding_machines;
+	std::condition_variable condition;
+	std::mutex mutex;
+	{
+		std::lock_guard machines_lock(machines_mutex_);
+		std::lock_guard lock(mutex);
+		outstanding_machines = machines_.size();
+
+		for(std::size_t index = 0; index < machines_.size(); ++index) {
+			const auto machine = ::Machine::get<MachineType>(*machines_[index].get());
+			queues_[index].enqueue([&mutex, &condition, machine, function, &outstanding_machines]() {
+				if(machine) function(machine);
+
+				std::lock_guard lock(mutex);
+				outstanding_machines--;
+				condition.notify_all();
+			});
+		}
+	}
+
+	std::unique_lock lock(mutex);
+	condition.wait(lock, [&outstanding_machines] { return !outstanding_machines; });
+}
+
+template <typename MachineType>
+void MultiInterface<MachineType>::perform_serial(const std::function<void(MachineType *)> &function) {
+	std::lock_guard machines_lock(machines_mutex_);
+	for(const auto &machine: machines_) {
+		const auto typed_machine = ::Machine::get<MachineType>(*machine.get());
+		if(typed_machine) function(typed_machine);
+	}
+}
+
+// MARK: - MultiScanProducer
+void MultiScanProducer::set_scan_target(Outputs::Display::ScanTarget *scan_target) {
+	scan_target_ = scan_target;
+
+	std::lock_guard machines_lock(machines_mutex_);
+	const auto machine = machines_.front()->scan_producer();
+	if(machine) machine->set_scan_target(scan_target);
+}
+
+Outputs::Display::ScanStatus MultiScanProducer::get_scan_status() const {
+	std::lock_guard machines_lock(machines_mutex_);
+	const auto machine = machines_.front()->scan_producer();
+	if(machine) return machine->get_scan_status();
+	return Outputs::Display::ScanStatus();
+}
+
+void MultiScanProducer::did_change_machine_order() {
+	if(scan_target_) scan_target_->will_change_owner();
+
+	perform_serial([](MachineTypes::ScanProducer *machine) {
+		machine->set_scan_target(nullptr);
+	});
+	std::lock_guard machines_lock(machines_mutex_);
+	const auto machine = machines_.front()->scan_producer();
+	if(machine) machine->set_scan_target(scan_target_);
+}
+
+// MARK: - MultiAudioProducer
+MultiAudioProducer::MultiAudioProducer(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines, std::recursive_mutex &machines_mutex) : MultiInterface(machines, machines_mutex) {
+	speaker_ = MultiSpeaker::create(machines);
+}
+
+Outputs::Speaker::Speaker *MultiAudioProducer::get_speaker() {
+	return speaker_;
+}
+
+void MultiAudioProducer::did_change_machine_order() {
+	if(speaker_) {
+		speaker_->set_new_front_machine(machines_.front().get());
+	}
+}
+
+// MARK: - MultiTimedMachine
+
+void MultiTimedMachine::run_for(Time::Seconds duration) {
+	perform_parallel([duration](::MachineTypes::TimedMachine *machine) {
+		if(machine->get_confidence() >= 0.01f) machine->run_for(duration);
+	});
+
+	if(delegate_) delegate_->did_run_machines(this);
+}

Analyser/Dynamic/MultiMachine/Implementation/MultiProducer.hpp

@@ -1,16 +1,16 @@
 //
-//  MultiCRTMachine.hpp
+//  MultiProducer.hpp
 //  Clock Signal
 //
 //  Created by Thomas Harte on 29/01/2018.
 //  Copyright 2018 Thomas Harte. All rights reserved.
 //
 
-#ifndef MultiCRTMachine_hpp
-#define MultiCRTMachine_hpp
+#ifndef MultiProducer_hpp
+#define MultiProducer_hpp
 
 #include "../../../../Concurrency/AsyncTaskQueue.hpp"
-#include "../../../../Machines/CRTMachine.hpp"
+#include "../../../../Machines/MachineTypes.hpp"
 #include "../../../../Machines/DynamicMachine.hpp"
 
 #include "MultiSpeaker.hpp"
@@ -22,6 +22,91 @@
 namespace Analyser {
 namespace Dynamic {
 
+template <typename MachineType> class MultiInterface {
+	public:
+		MultiInterface(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines, std::recursive_mutex &machines_mutex) :
+			machines_(machines), machines_mutex_(machines_mutex), queues_(machines.size()) {}
+
+	protected:
+		/*!
+			Performs a parallel for operation across all machines, performing the supplied
+			function on each and returning only once all applications have completed.
+
+			No guarantees are extended as to which thread operations will occur on.
+		*/
+		void perform_parallel(const std::function<void(MachineType *)> &);
+
+		/*!
+			Performs a serial for operation across all machines, performing the supplied
+			function on each on the calling thread.
+		*/
+		void perform_serial(const std::function<void(MachineType *)> &);
+
+	protected:
+		const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines_;
+		std::recursive_mutex &machines_mutex_;
+
+	private:
+		std::vector<Concurrency::AsyncTaskQueue> queues_;
+};
+
+class MultiTimedMachine: public MultiInterface<MachineTypes::TimedMachine>, public MachineTypes::TimedMachine {
+	public:
+		using MultiInterface::MultiInterface;
+
+		/*!
+			Provides a mechanism by which a delegate can be informed each time a call to run_for has
+			been received.
+		*/
+		struct Delegate {
+			virtual void did_run_machines(MultiTimedMachine *) = 0;
+		};
+		/// Sets @c delegate as the receiver of delegate messages.
+		void set_delegate(Delegate *delegate) {
+			delegate_ = delegate;
+		}
+
+		void run_for(Time::Seconds duration) final;
+
+	private:
+		void run_for(const Cycles) final {}
+		Delegate *delegate_ = nullptr;
+};
+
+class MultiScanProducer: public MultiInterface<MachineTypes::ScanProducer>, public MachineTypes::ScanProducer {
+	public:
+		using MultiInterface::MultiInterface;
+
+		/*!
+			Informs the MultiScanProducer that the order of machines has changed; it
+			uses this as an opportunity to synthesis any CRTMachine::Machine::Delegate messages that
+			are necessary to bridge the gap between one machine and the next.
+		*/
+		void did_change_machine_order();
+
+		void set_scan_target(Outputs::Display::ScanTarget *scan_target) final;
+		Outputs::Display::ScanStatus get_scan_status() const final;
+
+	private:
+		Outputs::Display::ScanTarget *scan_target_ = nullptr;
+};
+
+class MultiAudioProducer: public MultiInterface<MachineTypes::AudioProducer>, public MachineTypes::AudioProducer {
+	public:
+		MultiAudioProducer(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines, std::recursive_mutex &machines_mutex);
+
+		/*!
+			Informs the MultiAudio that the order of machines has changed; it
+			uses this as an opportunity to switch speaker delegates as appropriate.
+		*/
+		void did_change_machine_order();
+
+		Outputs::Speaker::Speaker *get_speaker() final;
+
+	private:
+		MultiSpeaker *speaker_ = nullptr;
+};
+
 /*!
 	Provides a class that multiplexes the CRT machine interface to multiple machines.
 
@@ -29,60 +114,9 @@ namespace Dynamic {
 	acquiring a supplied mutex. The owner should also call did_change_machine_order()
 	if the order of machines changes.
 */
-class MultiCRTMachine: public CRTMachine::Machine {
-	public:
-		MultiCRTMachine(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines, std::recursive_mutex &machines_mutex);
-
-		/*!
-			Informs the MultiCRTMachine that the order of machines has changed; the MultiCRTMachine
-			uses this as an opportunity to synthesis any CRTMachine::Machine::Delegate messages that
-			are necessary to bridge the gap between one machine and the next.
-		*/
-		void did_change_machine_order();
-
-		/*!
-			Provides a mechanism by which a delegate can be informed each time a call to run_for has
-			been received.
-		*/
-		struct Delegate {
-			virtual void multi_crt_did_run_machines() = 0;
-		};
-		/// Sets @c delegate as the receiver of delegate messages.
-		void set_delegate(Delegate *delegate) {
-			delegate_ = delegate;
-		}
-
-		// Below is the standard CRTMachine::Machine interface; see there for documentation.
-		void set_scan_target(Outputs::Display::ScanTarget *scan_target) override;
-		Outputs::Speaker::Speaker *get_speaker() override;
-		void run_for(Time::Seconds duration) override;
-
-	private:
-		void run_for(const Cycles cycles) override {}
-		const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines_;
-		std::recursive_mutex &machines_mutex_;
-		std::vector<Concurrency::AsyncTaskQueue> queues_;
-		MultiSpeaker *speaker_ = nullptr;
-		Delegate *delegate_ = nullptr;
-		Outputs::Display::ScanTarget *scan_target_ = nullptr;
-
-		/*!
-			Performs a parallel for operation across all machines, performing the supplied
-			function on each and returning only once all applications have completed.
-
-			No guarantees are extended as to which thread operations will occur on.
-		*/
-		void perform_parallel(const std::function<void(::CRTMachine::Machine *)> &);
-
-		/*!
-			Performs a serial for operation across all machines, performing the supplied
-			function on each on the calling thread.
-		*/
-		void perform_serial(const std::function<void(::CRTMachine::Machine *)> &);
-};
 
 }
 }
 
 
-#endif /* MultiCRTMachine_hpp */
+#endif /* MultiProducer_hpp */

Analyser/Dynamic/MultiMachine/Implementation/MultiSpeaker.cpp

@@ -13,7 +13,7 @@ using namespace Analyser::Dynamic;
 MultiSpeaker *MultiSpeaker::create(const std::vector<std::unique_ptr<::Machine::DynamicMachine>> &machines) {
 	std::vector<Outputs::Speaker::Speaker *> speakers;
 	for(const auto &machine: machines) {
-		Outputs::Speaker::Speaker *speaker = machine->crt_machine()->get_speaker();
+		Outputs::Speaker::Speaker *speaker = machine->audio_producer()->get_speaker();
 		if(speaker) speakers.push_back(speaker);
 	}
 	if(speakers.empty()) return nullptr;
@@ -34,43 +34,59 @@ float MultiSpeaker::get_ideal_clock_rate_in_range(float minimum, float maximum)
 		ideal += speaker->get_ideal_clock_rate_in_range(minimum, maximum);
 	}
 
-	return ideal / static_cast<float>(speakers_.size());
+	return ideal / float(speakers_.size());
 }
 
-void MultiSpeaker::set_output_rate(float cycles_per_second, int buffer_size) {
+void MultiSpeaker::set_computed_output_rate(float cycles_per_second, int buffer_size, bool stereo) {
+	stereo_output_ = stereo;
 	for(const auto &speaker: speakers_) {
-		speaker->set_output_rate(cycles_per_second, buffer_size);
+		speaker->set_computed_output_rate(cycles_per_second, buffer_size, stereo);
 	}
 }
 
-void MultiSpeaker::set_delegate(Outputs::Speaker::Speaker::Delegate *delegate) {
-	delegate_ = delegate;
+bool MultiSpeaker::get_is_stereo() {
+	// Return as stereo if any subspeaker is stereo.
+	for(const auto &speaker: speakers_) {
+		if(speaker->get_is_stereo()) {
+			return true;
+		}
+	}
+	return false;
+}
+
+void MultiSpeaker::set_output_volume(float volume) {
+	for(const auto &speaker: speakers_) {
+		speaker->set_output_volume(volume);
+	}
 }
 
 void MultiSpeaker::speaker_did_complete_samples(Speaker *speaker, const std::vector<int16_t> &buffer) {
-	if(!delegate_) return;
+	auto delegate = delegate_.load(std::memory_order::memory_order_relaxed);
+	if(!delegate) return;
 	{
-		std::lock_guard<std::mutex> lock_guard(front_speaker_mutex_);
+		std::lock_guard lock_guard(front_speaker_mutex_);
 		if(speaker != front_speaker_) return;
 	}
-	delegate_->speaker_did_complete_samples(this, buffer);
+	did_complete_samples(this, buffer, stereo_output_);
 }
 
 void MultiSpeaker::speaker_did_change_input_clock(Speaker *speaker) {
-	if(!delegate_) return;
+	auto delegate = delegate_.load(std::memory_order::memory_order_relaxed);
+	if(!delegate) return;
 	{
-		std::lock_guard<std::mutex> lock_guard(front_speaker_mutex_);
+		std::lock_guard lock_guard(front_speaker_mutex_);
 		if(speaker != front_speaker_) return;
 	}
-	delegate_->speaker_did_change_input_clock(this);
+	delegate->speaker_did_change_input_clock(this);
 }
 
 void MultiSpeaker::set_new_front_machine(::Machine::DynamicMachine *machine) {
 	{
-		std::lock_guard<std::mutex> lock_guard(front_speaker_mutex_);
-		front_speaker_ = machine->crt_machine()->get_speaker();
+		std::lock_guard lock_guard(front_speaker_mutex_);
+		front_speaker_ = machine->audio_producer()->get_speaker();
 	}
-	if(delegate_) {
-		delegate_->speaker_did_change_input_clock(this);
+	auto delegate = delegate_.load(std::memory_order::memory_order_relaxed);
+	if(delegate) {
+		delegate->speaker_did_change_input_clock(this);
 	}
 }

Analyser/Dynamic/MultiMachine/Implementation/MultiSpeaker.hpp

@@ -39,18 +39,20 @@ class MultiSpeaker: public Outputs::Speaker::Speaker, Outputs::Speaker::Speaker:
 
 		// Below is the standard Outputs::Speaker::Speaker interface; see there for documentation.
 		float get_ideal_clock_rate_in_range(float minimum, float maximum) override;
-		void set_output_rate(float cycles_per_second, int buffer_size) override;
-		void set_delegate(Outputs::Speaker::Speaker::Delegate *delegate) override;
+		void set_computed_output_rate(float cycles_per_second, int buffer_size, bool stereo) override;
+		bool get_is_stereo() override;
+		void set_output_volume(float) override;
 
 	private:
-		void speaker_did_complete_samples(Speaker *speaker, const std::vector<int16_t> &buffer) override;
-		void speaker_did_change_input_clock(Speaker *speaker) override;
+		void speaker_did_complete_samples(Speaker *speaker, const std::vector<int16_t> &buffer) final;
+		void speaker_did_change_input_clock(Speaker *speaker) final;
 		MultiSpeaker(const std::vector<Outputs::Speaker::Speaker *> &speakers);
 
 		std::vector<Outputs::Speaker::Speaker *> speakers_;
 		Outputs::Speaker::Speaker *front_speaker_ = nullptr;
-		Outputs::Speaker::Speaker::Delegate *delegate_ = nullptr;
 		std::mutex front_speaker_mutex_;
+
+		bool stereo_output_ = false;
 };
 
 }

Analyser/Dynamic/MultiMachine/MultiMachine.cpp

@@ -16,74 +16,55 @@ using namespace Analyser::Dynamic;
 MultiMachine::MultiMachine(std::vector<std::unique_ptr<DynamicMachine>> &&machines) :
 	machines_(std::move(machines)),
 	configurable_(machines_),
-	crt_machine_(machines_, machines_mutex_),
-	joystick_machine_(machines),
+	timed_machine_(machines_, machines_mutex_),
+	scan_producer_(machines_, machines_mutex_),
+	audio_producer_(machines_, machines_mutex_),
+	joystick_machine_(machines_),
 	keyboard_machine_(machines_),
 	media_target_(machines_) {
-	crt_machine_.set_delegate(this);
+	timed_machine_.set_delegate(this);
 }
 
 Activity::Source *MultiMachine::activity_source() {
 	return nullptr; // TODO
 }
 
-MediaTarget::Machine *MultiMachine::media_target() {
-	if(has_picked_) {
-		return machines_.front()->media_target();
-	} else {
-		return &media_target_;
+#define Provider(type, name, member)	\
+	type *MultiMachine::name() {	\
+		if(has_picked_) {	\
+			return machines_.front()->name();	\
+		} else {	\
+			return &member;	\
+		}	\
 	}
-}
 
-CRTMachine::Machine *MultiMachine::crt_machine() {
-	if(has_picked_) {
-		return machines_.front()->crt_machine();
-	} else {
-		return &crt_machine_;
-	}
-}
+Provider(Configurable::Device, configurable_device, configurable_)
+Provider(MachineTypes::TimedMachine, timed_machine, timed_machine_)
+Provider(MachineTypes::ScanProducer, scan_producer, scan_producer_)
+Provider(MachineTypes::AudioProducer, audio_producer, audio_producer_)
+Provider(MachineTypes::JoystickMachine, joystick_machine, joystick_machine_)
+Provider(MachineTypes::KeyboardMachine, keyboard_machine, keyboard_machine_)
+Provider(MachineTypes::MediaTarget, media_target, media_target_)
 
-JoystickMachine::Machine *MultiMachine::joystick_machine() {
-	if(has_picked_) {
-		return machines_.front()->joystick_machine();
-	} else {
-		return &joystick_machine_;
-	}
-}
-
-KeyboardMachine::Machine *MultiMachine::keyboard_machine() {
-	if(has_picked_) {
-		return machines_.front()->keyboard_machine();
-	} else {
-		return &keyboard_machine_;
-	}
-}
-
-MouseMachine::Machine *MultiMachine::mouse_machine() {
+MachineTypes::MouseMachine *MultiMachine::mouse_machine() {
 	// TODO.
 	return nullptr;
 }
 
-Configurable::Device *MultiMachine::configurable_device() {
-	if(has_picked_) {
-		return machines_.front()->configurable_device();
-	} else {
-		return &configurable_;
-	}
-}
+#undef Provider
 
 bool MultiMachine::would_collapse(const std::vector<std::unique_ptr<DynamicMachine>> &machines) {
 	return
-		(machines.front()->crt_machine()->get_confidence() > 0.9f) ||
-		(machines.front()->crt_machine()->get_confidence() >= 2.0f * machines[1]->crt_machine()->get_confidence());
+		(machines.front()->timed_machine()->get_confidence() > 0.9f) ||
+		(machines.front()->timed_machine()->get_confidence() >= 2.0f * machines[1]->timed_machine()->get_confidence());
 }
 
-void MultiMachine::multi_crt_did_run_machines() {
-	std::lock_guard<decltype(machines_mutex_)> machines_lock(machines_mutex_);
+void MultiMachine::did_run_machines(MultiTimedMachine *) {
+	std::lock_guard machines_lock(machines_mutex_);
 #ifndef NDEBUG
 	for(const auto &machine: machines_) {
-		CRTMachine::Machine *crt = machine->crt_machine();
-		LOGNBR(PADHEX(2) << crt->get_confidence() << " " << crt->debug_type() << "; ");
+		auto timed_machine = machine->timed_machine();
+		LOGNBR(PADHEX(2) << timed_machine->get_confidence() << " " << timed_machine->debug_type() << "; ");
 	}
 	LOGNBR(std::endl);
 #endif
@@ -91,13 +72,14 @@ void MultiMachine::multi_crt_did_run_machines() {
 	DynamicMachine *front = machines_.front().get();
 	std::stable_sort(machines_.begin(), machines_.end(),
 		[] (const std::unique_ptr<DynamicMachine> &lhs, const std::unique_ptr<DynamicMachine> &rhs){
-			CRTMachine::Machine *lhs_crt = lhs->crt_machine();
-			CRTMachine::Machine *rhs_crt = rhs->crt_machine();
-			return lhs_crt->get_confidence() > rhs_crt->get_confidence();
+			auto lhs_timed = lhs->timed_machine();
+			auto rhs_timed = rhs->timed_machine();
+			return lhs_timed->get_confidence() > rhs_timed->get_confidence();
 		});
 
 	if(machines_.front().get() != front) {
-		crt_machine_.did_change_machine_order();
+		scan_producer_.did_change_machine_order();
+		audio_producer_.did_change_machine_order();
 	}
 
 	if(would_collapse(machines_)) {
@@ -107,9 +89,28 @@ void MultiMachine::multi_crt_did_run_machines() {
 
 void MultiMachine::pick_first() {
 	has_picked_ = true;
+
+	// Ensure output rate specifics are properly copied; these may be set only once by the owner,
+	// but rather than being propagated directly by the MultiSpeaker only the derived computed
+	// output rate is propagated. So this ensures that if a new derivation is made, it's made correctly.
+	if(machines_[0]->audio_producer()) {
+		auto multi_speaker = audio_producer_.get_speaker();
+		auto specific_speaker = machines_[0]->audio_producer()->get_speaker();
+
+		if(specific_speaker && multi_speaker) {
+			specific_speaker->copy_output_rate(*multi_speaker);
+		}
+	}
+
+	// TODO: because it is not invalid for a caller to keep a reference to anything previously returned,
+	// this erase can be added only once the Multi machines that take static copies of the machines list
+	// are updated.
+	//
+	// Example failing use case otherwise: a caller still has reference to the MultiJoystickMachine, and
+	// it has dangling references to the various JoystickMachines.
+	//
+	// This gets into particularly long grass with the MultiConfigurable and its MultiStruct.
 //	machines_.erase(machines_.begin() + 1, machines_.end());
-	// TODO: this isn't quite correct, because it may leak OpenGL/etc resources through failure to
-	// request a close_output while the context is active.
 }
 
 void *MultiMachine::raw_pointer() {

Analyser/Dynamic/MultiMachine/MultiMachine.hpp

@@ -11,8 +11,9 @@
 
 #include "../../../Machines/DynamicMachine.hpp"
 
+#include "Implementation/MultiProducer.hpp"
 #include "Implementation/MultiConfigurable.hpp"
-#include "Implementation/MultiCRTMachine.hpp"
+#include "Implementation/MultiProducer.hpp"
 #include "Implementation/MultiJoystickMachine.hpp"
 #include "Implementation/MultiKeyboardMachine.hpp"
 #include "Implementation/MultiMediaTarget.hpp"
@@ -38,7 +39,7 @@ namespace Dynamic {
 	If confidence for any machine becomes disproportionately low compared to
 	the others in the set, that machine stops running.
 */
-class MultiMachine: public ::Machine::DynamicMachine, public MultiCRTMachine::Delegate {
+class MultiMachine: public ::Machine::DynamicMachine, public MultiTimedMachine::Delegate {
 	public:
 		/*!
 			Allows a potential MultiMachine creator to enquire as to whether there's any benefit in
@@ -50,23 +51,27 @@ class MultiMachine: public ::Machine::DynamicMachine, public MultiCRTMachine::De
 		static bool would_collapse(const std::vector<std::unique_ptr<DynamicMachine>> &machines);
 		MultiMachine(std::vector<std::unique_ptr<DynamicMachine>> &&machines);
 
-		Activity::Source *activity_source() override;
-		Configurable::Device *configurable_device() override;
-		CRTMachine::Machine *crt_machine() override;
-		JoystickMachine::Machine *joystick_machine() override;
-		MouseMachine::Machine *mouse_machine() override;
-		KeyboardMachine::Machine *keyboard_machine() override;
-		MediaTarget::Machine *media_target() override;
-		void *raw_pointer() override;
+		Activity::Source *activity_source() final;
+		Configurable::Device *configurable_device() final;
+		MachineTypes::TimedMachine *timed_machine() final;
+		MachineTypes::ScanProducer *scan_producer() final;
+		MachineTypes::AudioProducer *audio_producer() final;
+		MachineTypes::JoystickMachine *joystick_machine() final;
+		MachineTypes::KeyboardMachine *keyboard_machine() final;
+		MachineTypes::MouseMachine *mouse_machine() final;
+		MachineTypes::MediaTarget *media_target() final;
+		void *raw_pointer() final;
 
 	private:
-		void multi_crt_did_run_machines() override;
+		void did_run_machines(MultiTimedMachine *) final;
 
 		std::vector<std::unique_ptr<DynamicMachine>> machines_;
 		std::recursive_mutex machines_mutex_;
 
 		MultiConfigurable configurable_;
-		MultiCRTMachine crt_machine_;
+		MultiTimedMachine timed_machine_;
+		MultiScanProducer scan_producer_;
+		MultiAudioProducer audio_producer_;
 		MultiJoystickMachine joystick_machine_;
 		MultiKeyboardMachine keyboard_machine_;
 		MultiMediaTarget media_target_;

Analyser/Machines.hpp

@@ -15,6 +15,7 @@ enum class Machine {
 	AmstradCPC,
 	AppleII,
 	Atari2600,
+	AtariST,
 	ColecoVision,
 	Electron,
 	Macintosh,

Analyser/Static/Acorn/Disk.cpp

@@ -10,7 +10,7 @@
 
 #include "../../../Storage/Disk/Controller/DiskController.hpp"
 #include "../../../Storage/Disk/Encodings/MFM/Parser.hpp"
-#include "../../../NumberTheory/CRC.hpp"
+#include "../../../Numeric/CRC.hpp"
 
 #include <algorithm>
 
@@ -18,11 +18,11 @@ using namespace Analyser::Static::Acorn;
 
 std::unique_ptr<Catalogue> Analyser::Static::Acorn::GetDFSCatalogue(const std::shared_ptr<Storage::Disk::Disk> &disk) {
 	// c.f. http://beebwiki.mdfs.net/Acorn_DFS_disc_format
-	std::unique_ptr<Catalogue> catalogue(new Catalogue);
+	auto catalogue = std::make_unique<Catalogue>();
 	Storage::Encodings::MFM::Parser parser(false, disk);
 
-	Storage::Encodings::MFM::Sector *names = parser.get_sector(0, 0, 0);
-	Storage::Encodings::MFM::Sector *details = parser.get_sector(0, 0, 1);
+	const Storage::Encodings::MFM::Sector *const names = parser.get_sector(0, 0, 0);
+	const Storage::Encodings::MFM::Sector *const details = parser.get_sector(0, 0, 1);
 
 	if(!names || !details) return nullptr;
 	if(names->samples.empty() || details->samples.empty()) return nullptr;
@@ -48,18 +48,18 @@ std::unique_ptr<Catalogue> Analyser::Static::Acorn::GetDFSCatalogue(const std::s
 		char name[10];
 		snprintf(name, 10, "%c.%.7s", names->samples[0][file_offset + 7] & 0x7f, &names->samples[0][file_offset]);
 		new_file.name = name;
-		new_file.load_address = (uint32_t)(details->samples[0][file_offset] | (details->samples[0][file_offset+1] << 8) | ((details->samples[0][file_offset+6]&0x0c) << 14));
-		new_file.execution_address = (uint32_t)(details->samples[0][file_offset+2] | (details->samples[0][file_offset+3] << 8) | ((details->samples[0][file_offset+6]&0xc0) << 10));
-		new_file.is_protected = !!(names->samples[0][file_offset + 7] & 0x80);
+		new_file.load_address = uint32_t(details->samples[0][file_offset] | (details->samples[0][file_offset+1] << 8) | ((details->samples[0][file_offset+6]&0x0c) << 14));
+		new_file.execution_address = uint32_t(details->samples[0][file_offset+2] | (details->samples[0][file_offset+3] << 8) | ((details->samples[0][file_offset+6]&0xc0) << 10));
+		new_file.is_protected = names->samples[0][file_offset + 7] & 0x80;
 
-		long data_length = static_cast<long>(details->samples[0][file_offset+4] | (details->samples[0][file_offset+5] << 8) | ((details->samples[0][file_offset+6]&0x30) << 12));
+		long data_length = long(details->samples[0][file_offset+4] | (details->samples[0][file_offset+5] << 8) | ((details->samples[0][file_offset+6]&0x30) << 12));
 		int start_sector = details->samples[0][file_offset+7] | ((details->samples[0][file_offset+6]&0x03) << 8);
-		new_file.data.reserve(static_cast<std::size_t>(data_length));
+		new_file.data.reserve(size_t(data_length));
 
 		if(start_sector < 2) continue;
 		while(data_length > 0) {
-			uint8_t sector = static_cast<uint8_t>(start_sector % 10);
-			uint8_t track = static_cast<uint8_t>(start_sector / 10);
+			uint8_t sector = uint8_t(start_sector % 10);
+			uint8_t track = uint8_t(start_sector / 10);
 			start_sector++;
 
 			Storage::Encodings::MFM::Sector *next_sector = parser.get_sector(0, track, sector);
@@ -75,7 +75,7 @@ std::unique_ptr<Catalogue> Analyser::Static::Acorn::GetDFSCatalogue(const std::s
 	return catalogue;
 }
 std::unique_ptr<Catalogue> Analyser::Static::Acorn::GetADFSCatalogue(const std::shared_ptr<Storage::Disk::Disk> &disk) {
-	std::unique_ptr<Catalogue> catalogue(new Catalogue);
+	auto catalogue = std::make_unique<Catalogue>();
 	Storage::Encodings::MFM::Parser parser(true, disk);
 
 	Storage::Encodings::MFM::Sector *free_space_map_second_half = parser.get_sector(0, 0, 1);
@@ -84,7 +84,7 @@ std::unique_ptr<Catalogue> Analyser::Static::Acorn::GetADFSCatalogue(const std::
 	std::vector<uint8_t> root_directory;
 	root_directory.reserve(5 * 256);
 	for(uint8_t c = 2; c < 7; c++) {
-		Storage::Encodings::MFM::Sector *sector = parser.get_sector(0, 0, c);
+		const Storage::Encodings::MFM::Sector *const sector = parser.get_sector(0, 0, c);
 		if(!sector) return nullptr;
 		root_directory.insert(root_directory.end(), sector->samples[0].begin(), sector->samples[0].end());
 	}

Analyser/Static/Acorn/StaticAnalyser.cpp

@@ -29,7 +29,7 @@ static std::vector<std::shared_ptr<Storage::Cartridge::Cartridge>>
 		if(segment.data.size() != 0x4000 && segment.data.size() != 0x2000) continue;
 
 		// is a copyright string present?
-		uint8_t copyright_offset = segment.data[7];
+		const uint8_t copyright_offset = segment.data[7];
 		if(
 			segment.data[copyright_offset] != 0x00 ||
 			segment.data[copyright_offset+1] != 0x28 ||
@@ -57,9 +57,8 @@ static std::vector<std::shared_ptr<Storage::Cartridge::Cartridge>>
 	return acorn_cartridges;
 }
 
-Analyser::Static::TargetList Analyser::Static::Acorn::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms) {
-	std::unique_ptr<Target> target(new Target);
-	target->machine = Machine::Electron;
+Analyser::Static::TargetList Analyser::Static::Acorn::GetTargets(const Media &media, const std::string &, TargetPlatform::IntType) {
+	auto target = std::make_unique<Target>();
 	target->confidence = 0.5; // TODO: a proper estimation
 	target->has_dfs = false;
 	target->has_adfs = false;
@@ -84,8 +83,8 @@ Analyser::Static::TargetList Analyser::Static::Acorn::GetTargets(const Media &me
 			// check also for a continuous threading of BASIC lines; if none then this probably isn't BASIC code,
 			// so that's also justification to *RUN
 			std::size_t pointer = 0;
-			uint8_t *data = &files.front().data[0];
-			std::size_t data_size = files.front().data.size();
+			uint8_t *const data = &files.front().data[0];
+			const std::size_t data_size = files.front().data.size();
 			while(1) {
 				if(pointer >= data_size-1 || data[pointer] != 13) {
 					is_basic = false;

Analyser/Static/Acorn/Tape.cpp

@@ -10,13 +10,13 @@
 
 #include <deque>
 
-#include "../../../NumberTheory/CRC.hpp"
+#include "../../../Numeric/CRC.hpp"
 #include "../../../Storage/Tape/Parsers/Acorn.hpp"
 
 using namespace Analyser::Static::Acorn;
 
 static std::unique_ptr<File::Chunk> GetNextChunk(const std::shared_ptr<Storage::Tape::Tape> &tape, Storage::Tape::Acorn::Parser &parser) {
-	std::unique_ptr<File::Chunk> new_chunk(new File::Chunk);
+	auto new_chunk = std::make_unique<File::Chunk>();
 	int shift_register = 0;
 
 // TODO: move this into the parser
@@ -41,24 +41,24 @@ static std::unique_ptr<File::Chunk> GetNextChunk(const std::shared_ptr<Storage::
 	char name[11];
 	std::size_t name_ptr = 0;
 	while(!tape->is_at_end() && name_ptr < sizeof(name)) {
-		name[name_ptr] = (char)parser.get_next_byte(tape);
+		name[name_ptr] = char(parser.get_next_byte(tape));
 		if(!name[name_ptr]) break;
-		name_ptr++;
+		++name_ptr;
 	}
 	name[sizeof(name)-1] = '\0';
 	new_chunk->name = name;
 
 	// addresses
-	new_chunk->load_address = (uint32_t)parser.get_next_word(tape);
-	new_chunk->execution_address = (uint32_t)parser.get_next_word(tape);
-	new_chunk->block_number = static_cast<uint16_t>(parser.get_next_short(tape));
-	new_chunk->block_length = static_cast<uint16_t>(parser.get_next_short(tape));
-	new_chunk->block_flag = static_cast<uint8_t>(parser.get_next_byte(tape));
-	new_chunk->next_address = (uint32_t)parser.get_next_word(tape);
+	new_chunk->load_address = uint32_t(parser.get_next_word(tape));
+	new_chunk->execution_address = uint32_t(parser.get_next_word(tape));
+	new_chunk->block_number = uint16_t(parser.get_next_short(tape));
+	new_chunk->block_length = uint16_t(parser.get_next_short(tape));
+	new_chunk->block_flag = uint8_t(parser.get_next_byte(tape));
+	new_chunk->next_address = uint32_t(parser.get_next_word(tape));
 
 	uint16_t calculated_header_crc = parser.get_crc();
-	uint16_t stored_header_crc = static_cast<uint16_t>(parser.get_next_short(tape));
-	stored_header_crc = static_cast<uint16_t>((stored_header_crc >> 8) | (stored_header_crc << 8));
+	uint16_t stored_header_crc = uint16_t(parser.get_next_short(tape));
+	stored_header_crc = uint16_t((stored_header_crc >> 8) | (stored_header_crc << 8));
 	new_chunk->header_crc_matched = stored_header_crc == calculated_header_crc;
 
 	if(!new_chunk->header_crc_matched) return nullptr;
@@ -66,13 +66,13 @@ static std::unique_ptr<File::Chunk> GetNextChunk(const std::shared_ptr<Storage::
 	parser.reset_crc();
 	new_chunk->data.reserve(new_chunk->block_length);
 	for(int c = 0; c < new_chunk->block_length; c++) {
-		new_chunk->data.push_back(static_cast<uint8_t>(parser.get_next_byte(tape)));
+		new_chunk->data.push_back(uint8_t(parser.get_next_byte(tape)));
 	}
 
 	if(new_chunk->block_length && !(new_chunk->block_flag&0x40)) {
 		uint16_t calculated_data_crc = parser.get_crc();
-		uint16_t stored_data_crc = static_cast<uint16_t>(parser.get_next_short(tape));
-		stored_data_crc = static_cast<uint16_t>((stored_data_crc >> 8) | (stored_data_crc << 8));
+		uint16_t stored_data_crc = uint16_t(parser.get_next_short(tape));
+		stored_data_crc = uint16_t((stored_data_crc >> 8) | (stored_data_crc << 8));
 		new_chunk->data_crc_matched = stored_data_crc == calculated_data_crc;
 	} else {
 		new_chunk->data_crc_matched = true;
@@ -90,7 +90,7 @@ static std::unique_ptr<File> GetNextFile(std::deque<File::Chunk> &chunks) {
 	if(!chunks.size()) return nullptr;
 
 	// accumulate chunks for as long as block number is sequential and the end-of-file bit isn't set
-	std::unique_ptr<File> file(new File);
+	auto file = std::make_unique<File>();
 
 	uint16_t block_number = 0;
 

Analyser/Static/Acorn/Target.hpp

@@ -9,6 +9,7 @@
 #ifndef Analyser_Static_Acorn_Target_h
 #define Analyser_Static_Acorn_Target_h
 
+#include "../../../Reflection/Struct.hpp"
 #include "../StaticAnalyser.hpp"
 #include <string>
 
@@ -16,11 +17,18 @@ namespace Analyser {
 namespace Static {
 namespace Acorn {
 
-struct Target: public ::Analyser::Static::Target {
+struct Target: public ::Analyser::Static::Target, public Reflection::StructImpl<Target> {
 	bool has_adfs = false;
 	bool has_dfs = false;
 	bool should_shift_restart = false;
 	std::string loading_command;
+
+	Target() : Analyser::Static::Target(Machine::Electron) {
+		if(needs_declare()) {
+			DeclareField(has_adfs);
+			DeclareField(has_dfs);
+		}
+	}
 };
 
 }

Analyser/Static/AmstradCPC/StaticAnalyser.cpp

@@ -179,10 +179,9 @@ static bool CheckBootSector(const std::shared_ptr<Storage::Disk::Disk> &disk, co
 	return false;
 }
 
-Analyser::Static::TargetList Analyser::Static::AmstradCPC::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms) {
+Analyser::Static::TargetList Analyser::Static::AmstradCPC::GetTargets(const Media &media, const std::string &, TargetPlatform::IntType) {
 	TargetList destination;
-	std::unique_ptr<Target> target(new Target);
-	target->machine = Machine::AmstradCPC;
+	auto target = std::make_unique<Target>();
 	target->confidence = 0.5;
 
 	target->model = Target::Model::CPC6128;

Analyser/Static/AmstradCPC/Target.hpp

@@ -9,6 +9,8 @@
 #ifndef Analyser_Static_AmstradCPC_Target_h
 #define Analyser_Static_AmstradCPC_Target_h
 
+#include "../../../Reflection/Enum.hpp"
+#include "../../../Reflection/Struct.hpp"
 #include "../StaticAnalyser.hpp"
 #include <string>
 
@@ -16,15 +18,17 @@ namespace Analyser {
 namespace Static {
 namespace AmstradCPC {
 
-struct Target: public ::Analyser::Static::Target {
-	enum class Model {
-		CPC464,
-		CPC664,
-		CPC6128
-	};
-
+struct Target: public Analyser::Static::Target, public Reflection::StructImpl<Target> {
+	ReflectableEnum(Model, CPC464, CPC664, CPC6128);
 	Model model = Model::CPC464;
 	std::string loading_command;
+
+	Target() : Analyser::Static::Target(Machine::AmstradCPC) {
+		if(needs_declare()) {
+			DeclareField(model);
+			AnnounceEnum(Model);
+		}
+	}
 };
 
 }

Analyser/Static/AppleII/StaticAnalyser.cpp

@@ -9,9 +9,8 @@
 #include "StaticAnalyser.hpp"
 #include "Target.hpp"
 
-Analyser::Static::TargetList Analyser::Static::AppleII::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms) {
-	auto target = std::unique_ptr<Target>(new Target);
-	target->machine = Machine::AppleII;
+Analyser::Static::TargetList Analyser::Static::AppleII::GetTargets(const Media &media, const std::string &, TargetPlatform::IntType) {
+	auto target = std::make_unique<Target>();
 	target->media = media;
 
 	if(!target->media.disks.empty())

Analyser/Static/AppleII/Target.hpp

@@ -9,27 +9,38 @@
 #ifndef Target_h
 #define Target_h
 
+#include "../../../Reflection/Enum.hpp"
+#include "../../../Reflection/Struct.hpp"
 #include "../StaticAnalyser.hpp"
 
 namespace Analyser {
 namespace Static {
 namespace AppleII {
 
-struct Target: public ::Analyser::Static::Target {
-	enum class Model {
+struct Target: public Analyser::Static::Target, public Reflection::StructImpl<Target> {
+	ReflectableEnum(Model,
 		II,
 		IIplus,
 		IIe,
 		EnhancedIIe
-	};
-	enum class DiskController {
+	);
+	ReflectableEnum(DiskController,
 		None,
 		SixteenSector,
 		ThirteenSector
-	};
+	);
 
 	Model model = Model::IIe;
 	DiskController disk_controller = DiskController::None;
+
+	Target() : Analyser::Static::Target(Machine::AppleII) {
+		if(needs_declare()) {
+			DeclareField(model);
+			DeclareField(disk_controller);
+			AnnounceEnum(Model);
+			AnnounceEnum(DiskController);
+		}
+	}
 };
 
 }

Analyser/Static/Atari2600/StaticAnalyser.cpp

@@ -12,27 +12,26 @@
 
 #include "../Disassembler/6502.hpp"
 
-using namespace Analyser::Static::Atari;
+using namespace Analyser::Static::Atari2600;
+using Target = Analyser::Static::Atari2600::Target;
 
-static void DeterminePagingFor2kCartridge(Analyser::Static::Atari::Target &target, const Storage::Cartridge::Cartridge::Segment &segment) {
-	// if this is a 2kb cartridge then it's definitely either unpaged or a CommaVid
-	uint16_t entry_address, break_address;
+static void DeterminePagingFor2kCartridge(Target &target, const Storage::Cartridge::Cartridge::Segment &segment) {
+	// If this is a 2kb cartridge then it's definitely either unpaged or a CommaVid.
+	const uint16_t entry_address = uint16_t(segment.data[0x7fc] | (segment.data[0x7fd] << 8)) & 0x1fff;
+	const uint16_t break_address = uint16_t(segment.data[0x7fe] | (segment.data[0x7ff] << 8)) & 0x1fff;
 
-	entry_address = (static_cast<uint16_t>(segment.data[0x7fc] | (segment.data[0x7fd] << 8))) & 0x1fff;
-	break_address = (static_cast<uint16_t>(segment.data[0x7fe] | (segment.data[0x7ff] << 8))) & 0x1fff;
-
-	// a CommaVid start address needs to be outside of its RAM
+	// A CommaVid start address needs to be outside of its RAM.
 	if(entry_address < 0x1800 || break_address < 0x1800) return;
 
 	std::function<std::size_t(uint16_t address)> high_location_mapper = [](uint16_t address) {
 		address &= 0x1fff;
-		return static_cast<std::size_t>(address - 0x1800);
+		return size_t(address - 0x1800);
 	};
 	Analyser::Static::MOS6502::Disassembly high_location_disassembly =
 		Analyser::Static::MOS6502::Disassemble(segment.data, high_location_mapper, {entry_address, break_address});
 
-	// assume that any kind of store that looks likely to be intended for large amounts of memory implies
-	// large amounts of memory
+	// Assume that any kind of store that looks likely to be intended for large amounts of memory implies
+	// large amounts of memory.
 	bool has_wide_area_store = false;
 	for(std::map<uint16_t, Analyser::Static::MOS6502::Instruction>::value_type &entry : high_location_disassembly.instructions_by_address) {
 		if(entry.second.operation == Analyser::Static::MOS6502::Instruction::STA) {
@@ -44,28 +43,28 @@ static void DeterminePagingFor2kCartridge(Analyser::Static::Atari::Target &targe
 		}
 	}
 
-	// conclude that this is a CommaVid if it attempted to write something to the CommaVid RAM locations;
+	// Conclude that this is a CommaVid if it attempted to write something to the CommaVid RAM locations;
 	// caveat: false positives aren't likely to be problematic; a false positive is a 2KB ROM that always addresses
 	// itself so as to land in ROM even if mapped as a CommaVid and this code is on the fence as to whether it
-	// attempts to modify itself but it probably doesn't
-	if(has_wide_area_store) target.paging_model = Analyser::Static::Atari::Target::PagingModel::CommaVid;
+	// attempts to modify itself but it probably doesn't.
+	if(has_wide_area_store) target.paging_model = Target::PagingModel::CommaVid;
 }
 
-static void DeterminePagingFor8kCartridge(Analyser::Static::Atari::Target &target, const Storage::Cartridge::Cartridge::Segment &segment, const Analyser::Static::MOS6502::Disassembly &disassembly) {
+static void DeterminePagingFor8kCartridge(Target &target, const Storage::Cartridge::Cartridge::Segment &segment, const Analyser::Static::MOS6502::Disassembly &disassembly) {
 	// Activision stack titles have their vectors at the top of the low 4k, not the top, and
 	// always list 0xf000 as both vectors; they do not repeat them, and, inexplicably, they all
-	// issue an SEI as their first instruction (maybe some sort of relic of the development environment?)
+	// issue an SEI as their first instruction (maybe some sort of relic of the development environment?).
 	if(
 		segment.data[4095] == 0xf0 && segment.data[4093] == 0xf0 && segment.data[4094] == 0x00 && segment.data[4092] == 0x00 &&
 		(segment.data[8191] != 0xf0 || segment.data[8189] != 0xf0 || segment.data[8190] != 0x00 || segment.data[8188] != 0x00) &&
 		segment.data[0] == 0x78
 	) {
-		target.paging_model = Analyser::Static::Atari::Target::PagingModel::ActivisionStack;
+		target.paging_model = Target::PagingModel::ActivisionStack;
 		return;
 	}
 
-	// make an assumption that this is the Atari paging model
-	target.paging_model = Analyser::Static::Atari::Target::PagingModel::Atari8k;
+	// Make an assumption that this is the Atari paging model.
+	target.paging_model = Target::PagingModel::Atari8k;
 
 	std::set<uint16_t> internal_accesses;
 	internal_accesses.insert(disassembly.internal_stores.begin(), disassembly.internal_stores.end());
@@ -85,13 +84,13 @@ static void DeterminePagingFor8kCartridge(Analyser::Static::Atari::Target &targe
 		tigervision_access_count += masked_address == 0x3f;
 	}
 
-	if(parker_access_count > atari_access_count) target.paging_model = Analyser::Static::Atari::Target::PagingModel::ParkerBros;
-	else if(tigervision_access_count > atari_access_count) target.paging_model = Analyser::Static::Atari::Target::PagingModel::Tigervision;
+	if(parker_access_count > atari_access_count) target.paging_model = Target::PagingModel::ParkerBros;
+	else if(tigervision_access_count > atari_access_count) target.paging_model = Target::PagingModel::Tigervision;
 }
 
-static void DeterminePagingFor16kCartridge(Analyser::Static::Atari::Target &target, const Storage::Cartridge::Cartridge::Segment &segment, const Analyser::Static::MOS6502::Disassembly &disassembly) {
-	// make an assumption that this is the Atari paging model
-	target.paging_model = Analyser::Static::Atari::Target::PagingModel::Atari16k;
+static void DeterminePagingFor16kCartridge(Target &target, const Storage::Cartridge::Cartridge::Segment &, const Analyser::Static::MOS6502::Disassembly &disassembly) {
+	// Make an assumption that this is the Atari paging model.
+	target.paging_model = Target::PagingModel::Atari16k;
 
 	std::set<uint16_t> internal_accesses;
 	internal_accesses.insert(disassembly.internal_stores.begin(), disassembly.internal_stores.end());
@@ -106,33 +105,31 @@ static void DeterminePagingFor16kCartridge(Analyser::Static::Atari::Target &targ
 		mnetwork_access_count += masked_address >= 0x1fe0 && masked_address < 0x1ffb;
 	}
 
-	if(mnetwork_access_count > atari_access_count) target.paging_model = Analyser::Static::Atari::Target::PagingModel::MNetwork;
+	if(mnetwork_access_count > atari_access_count) target.paging_model = Target::PagingModel::MNetwork;
 }
 
-static void DeterminePagingFor64kCartridge(Analyser::Static::Atari::Target &target, const Storage::Cartridge::Cartridge::Segment &segment, const Analyser::Static::MOS6502::Disassembly &disassembly) {
-	// make an assumption that this is a Tigervision if there is a write to 3F
+static void DeterminePagingFor64kCartridge(Target &target, const Storage::Cartridge::Cartridge::Segment &, const Analyser::Static::MOS6502::Disassembly &disassembly) {
+	// Make an assumption that this is a Tigervision if there is a write to 3F.
 	target.paging_model =
 		(disassembly.external_stores.find(0x3f) != disassembly.external_stores.end()) ?
-			Analyser::Static::Atari::Target::PagingModel::Tigervision : Analyser::Static::Atari::Target::PagingModel::MegaBoy;
+			Target::PagingModel::Tigervision : Target::PagingModel::MegaBoy;
 }
 
-static void DeterminePagingForCartridge(Analyser::Static::Atari::Target &target, const Storage::Cartridge::Cartridge::Segment &segment) {
+static void DeterminePagingForCartridge(Target &target, const Storage::Cartridge::Cartridge::Segment &segment) {
 	if(segment.data.size() == 2048) {
 		DeterminePagingFor2kCartridge(target, segment);
 		return;
 	}
 
-	uint16_t entry_address, break_address;
-
-	entry_address = static_cast<uint16_t>(segment.data[segment.data.size() - 4] | (segment.data[segment.data.size() - 3] << 8));
-	break_address = static_cast<uint16_t>(segment.data[segment.data.size() - 2] | (segment.data[segment.data.size() - 1] << 8));
+	const uint16_t entry_address = uint16_t(segment.data[segment.data.size() - 4] | (segment.data[segment.data.size() - 3] << 8));
+	const uint16_t break_address = uint16_t(segment.data[segment.data.size() - 2] | (segment.data[segment.data.size() - 1] << 8));
 
 	std::function<std::size_t(uint16_t address)> address_mapper = [](uint16_t address) {
-		if(!(address & 0x1000)) return static_cast<std::size_t>(-1);
-		return static_cast<std::size_t>(address & 0xfff);
+		if(!(address & 0x1000)) return size_t(-1);
+		return size_t(address & 0xfff);
 	};
 
-	std::vector<uint8_t> final_4k(segment.data.end() - 4096, segment.data.end());
+	const std::vector<uint8_t> final_4k(segment.data.end() - 4096, segment.data.end());
 	Analyser::Static::MOS6502::Disassembly disassembly = Analyser::Static::MOS6502::Disassemble(final_4k, address_mapper, {entry_address, break_address});
 
 	switch(segment.data.size()) {
@@ -140,16 +137,16 @@ static void DeterminePagingForCartridge(Analyser::Static::Atari::Target &target,
 			DeterminePagingFor8kCartridge(target, segment, disassembly);
 		break;
 		case 10495:
-			target.paging_model = Analyser::Static::Atari::Target::PagingModel::Pitfall2;
+			target.paging_model = Target::PagingModel::Pitfall2;
 		break;
 		case 12288:
-			target.paging_model = Analyser::Static::Atari::Target::PagingModel::CBSRamPlus;
+			target.paging_model = Target::PagingModel::CBSRamPlus;
 		break;
 		case 16384:
 			DeterminePagingFor16kCartridge(target, segment, disassembly);
 		break;
 		case 32768:
-			target.paging_model = Analyser::Static::Atari::Target::PagingModel::Atari32k;
+			target.paging_model = Target::PagingModel::Atari32k;
 		break;
 		case 65536:
 			DeterminePagingFor64kCartridge(target, segment, disassembly);
@@ -158,11 +155,11 @@ static void DeterminePagingForCartridge(Analyser::Static::Atari::Target &target,
 		break;
 	}
 
-	// check for a Super Chip. Atari ROM images [almost] always have the same value stored over RAM
+	// Check for a Super Chip. Atari ROM images [almost] always have the same value stored over RAM
 	// regions; when they don't they at least seem to have the first 128 bytes be the same as the
 	// next 128 bytes. So check for that.
-	if(	target.paging_model != Analyser::Static::Atari::Target::PagingModel::CBSRamPlus &&
-		target.paging_model != Analyser::Static::Atari::Target::PagingModel::MNetwork) {
+	if(	target.paging_model != Target::PagingModel::CBSRamPlus &&
+		target.paging_model != Target::PagingModel::MNetwork) {
 		bool has_superchip = true;
 		for(std::size_t address = 0; address < 128; address++) {
 			if(segment.data[address] != segment.data[address+128]) {
@@ -173,20 +170,19 @@ static void DeterminePagingForCartridge(Analyser::Static::Atari::Target &target,
 		target.uses_superchip = has_superchip;
 	}
 
-	// check for a Tigervision or Tigervision-esque scheme
-	if(target.paging_model == Analyser::Static::Atari::Target::PagingModel::None && segment.data.size() > 4096) {
+	// Check for a Tigervision or Tigervision-esque scheme
+	if(target.paging_model == Target::PagingModel::None && segment.data.size() > 4096) {
 		bool looks_like_tigervision = disassembly.external_stores.find(0x3f) != disassembly.external_stores.end();
-		if(looks_like_tigervision) target.paging_model = Analyser::Static::Atari::Target::PagingModel::Tigervision;
+		if(looks_like_tigervision) target.paging_model = Target::PagingModel::Tigervision;
 	}
 }
 
-Analyser::Static::TargetList Analyser::Static::Atari::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms) {
+Analyser::Static::TargetList Analyser::Static::Atari2600::GetTargets(const Media &media, const std::string &, TargetPlatform::IntType) {
 	// TODO: sanity checking; is this image really for an Atari 2600?
-	std::unique_ptr<Analyser::Static::Atari::Target> target(new Analyser::Static::Atari::Target);
-	target->machine = Machine::Atari2600;
+	auto target = std::make_unique<Target>();
 	target->confidence = 0.5;
 	target->media.cartridges = media.cartridges;
-	target->paging_model = Analyser::Static::Atari::Target::PagingModel::None;
+	target->paging_model = Target::PagingModel::None;
 	target->uses_superchip = false;
 
 	// try to figure out the paging scheme

Analyser/Static/Atari2600/StaticAnalyser.hpp

@@ -15,7 +15,7 @@
 
 namespace Analyser {
 namespace Static {
-namespace Atari {
+namespace Atari2600 {
 
 TargetList GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms);
 

Analyser/Static/Atari2600/Target.hpp

@@ -6,14 +6,14 @@
 //  Copyright 2018 Thomas Harte. All rights reserved.
 //
 
-#ifndef Analyser_Static_Atari_Target_h
-#define Analyser_Static_Atari_Target_h
+#ifndef Analyser_Static_Atari2600_Target_h
+#define Analyser_Static_Atari2600_Target_h
 
 #include "../StaticAnalyser.hpp"
 
 namespace Analyser {
 namespace Static {
-namespace Atari {
+namespace Atari2600 {
 
 struct Target: public ::Analyser::Static::Target {
 	enum class PagingModel {
@@ -34,6 +34,8 @@ struct Target: public ::Analyser::Static::Target {
 	// TODO: shouldn't these be properties of the cartridge?
 	PagingModel paging_model = PagingModel::None;
 	bool uses_superchip = false;
+
+	Target() : Analyser::Static::Target(Machine::Atari2600) {}
 };
 
 }

Analyser/Static/AtariST/StaticAnalyser.cpp

@@ -0,0 +1,25 @@
+//
+//  StaticAnalyser.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 03/10/2019.
+//  Copyright © 2019 Thomas Harte. All rights reserved.
+//
+
+#include "StaticAnalyser.hpp"
+#include "Target.hpp"
+
+Analyser::Static::TargetList Analyser::Static::AtariST::GetTargets(const Media &media, const std::string &, TargetPlatform::IntType) {
+	// This analyser can comprehend disks and mass-storage devices only.
+	if(media.disks.empty()) return {};
+
+	// As there is at least one usable media image, wave it through.
+	Analyser::Static::TargetList targets;
+
+	using Target = Analyser::Static::AtariST::Target;
+	auto *const target = new Target();
+	target->media = media;
+	targets.push_back(std::unique_ptr<Analyser::Static::Target>(target));
+
+	return targets;
+}

Analyser/Static/AtariST/StaticAnalyser.hpp

@@ -0,0 +1,27 @@
+//
+//  StaticAnalyser.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 03/10/2019.
+//  Copyright © 2019 Thomas Harte. All rights reserved.
+//
+
+#ifndef Analyser_Static_AtariST_StaticAnalyser_hpp
+#define Analyser_Static_AtariST_StaticAnalyser_hpp
+
+#include "../StaticAnalyser.hpp"
+#include "../../../Storage/TargetPlatforms.hpp"
+#include <string>
+
+namespace Analyser {
+namespace Static {
+namespace AtariST {
+
+TargetList GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms);
+
+}
+}
+}
+
+
+#endif /* Analyser_Static_AtariST_StaticAnalyser_hpp */

Analyser/Static/AtariST/Target.hpp

@@ -0,0 +1,27 @@
+//
+//  Target.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 03/06/2019.
+//  Copyright © 2019 Thomas Harte. All rights reserved.
+//
+
+#ifndef Analyser_Static_AtariST_Target_h
+#define Analyser_Static_AtariST_Target_h
+
+#include "../../../Reflection/Struct.hpp"
+#include "../StaticAnalyser.hpp"
+
+namespace Analyser {
+namespace Static {
+namespace AtariST {
+
+struct Target: public Analyser::Static::Target, public Reflection::StructImpl<Target> {
+	Target() : Analyser::Static::Target(Machine::AtariST) {}
+};
+
+}
+}
+}
+
+#endif /* Analyser_Static_AtariST_Target_h */

Analyser/Static/Coleco/StaticAnalyser.cpp

@@ -22,7 +22,7 @@ static std::vector<std::shared_ptr<Storage::Cartridge::Cartridge>>
 
 		// the two bytes that will be first must be 0xaa and 0x55, either way around
 		auto *start = &segment.data[0];
-		if((data_size & static_cast<std::size_t>(~8191)) > 32768) {
+		if((data_size & size_t(~8191)) > 32768) {
 			start = &segment.data[segment.data.size() - 16384];
 		}
 		if(start[0] != 0xaa && start[0] != 0x55 && start[1] != 0xaa && start[1] != 0x55) continue;
@@ -52,10 +52,9 @@ static std::vector<std::shared_ptr<Storage::Cartridge::Cartridge>>
 	return coleco_cartridges;
 }
 
-Analyser::Static::TargetList Analyser::Static::Coleco::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms) {
+Analyser::Static::TargetList Analyser::Static::Coleco::GetTargets(const Media &media, const std::string &, TargetPlatform::IntType) {
 	TargetList targets;
-	std::unique_ptr<Target> target(new Target);
-	target->machine = Machine::ColecoVision;
+	auto target = std::make_unique<Target>(Machine::ColecoVision);
 	target->confidence = 1.0f - 1.0f / 32768.0f;
 	target->media.cartridges = ColecoCartridgesFrom(media.cartridges);
 	if(!target->media.empty())

Analyser/Static/Commodore/Disk.cpp

@@ -19,12 +19,10 @@ using namespace Analyser::Static::Commodore;
 
 class CommodoreGCRParser: public Storage::Disk::Controller {
 	public:
-		std::shared_ptr<Storage::Disk::Drive> drive;
-
 		CommodoreGCRParser() : Storage::Disk::Controller(4000000), shift_register_(0), track_(1) {
-			drive.reset(new Storage::Disk::Drive(4000000, 300, 2));
-			set_drive(drive);
-			drive->set_motor_on(true);
+			emplace_drive(4000000, 300, 2);
+			set_drive(1);
+			get_drive().set_motor_on(true);
 		}
 
 		struct Sector {
@@ -40,7 +38,7 @@ class CommodoreGCRParser: public Storage::Disk::Controller {
 			@returns a sector if one was found; @c nullptr otherwise.
 		*/
 		std::shared_ptr<Sector> get_sector(uint8_t track, uint8_t sector) {
-			int difference = static_cast<int>(track) - static_cast<int>(track_);
+			int difference = int(track) - int(track_);
 			track_ = track;
 
 			if(difference) {
@@ -61,6 +59,10 @@ class CommodoreGCRParser: public Storage::Disk::Controller {
 			return get_sector(sector);
 		}
 
+		void set_disk(const std::shared_ptr<Storage::Disk::Disk> &disk) {
+			get_drive().set_disk(disk);
+		}
+
 	private:
 		unsigned int shift_register_;
 		int index_count_;
@@ -69,7 +71,7 @@ class CommodoreGCRParser: public Storage::Disk::Controller {
 		std::shared_ptr<Sector> sector_cache_[65536];
 
 		void process_input_bit(int value) {
-			shift_register_ = ((shift_register_ << 1) | static_cast<unsigned int>(value)) & 0x3ff;
+			shift_register_ = ((shift_register_ << 1) | unsigned(value)) & 0x3ff;
 			bit_count_++;
 		}
 
@@ -110,22 +112,22 @@ class CommodoreGCRParser: public Storage::Disk::Controller {
 		}
 
 		std::shared_ptr<Sector> get_sector(uint8_t sector) {
-			uint16_t sector_address = static_cast<uint16_t>((track_ << 8) | sector);
+			const uint16_t sector_address = uint16_t((track_ << 8) | sector);
 			if(sector_cache_[sector_address]) return sector_cache_[sector_address];
 
-			std::shared_ptr<Sector> first_sector = get_next_sector();
+			const std::shared_ptr<Sector> first_sector = get_next_sector();
 			if(!first_sector) return first_sector;
 			if(first_sector->sector == sector) return first_sector;
 
 			while(1) {
-				std::shared_ptr<Sector> next_sector = get_next_sector();
+				const std::shared_ptr<Sector> next_sector = get_next_sector();
 				if(next_sector->sector == first_sector->sector) return nullptr;
 				if(next_sector->sector == sector) return next_sector;
 			}
 		}
 
 		std::shared_ptr<Sector> get_next_sector() {
-			std::shared_ptr<Sector> sector(new Sector);
+			auto sector = std::make_shared<Sector>();
 			const int max_index_count = index_count_ + 2;
 
 			while(index_count_ < max_index_count) {
@@ -136,12 +138,12 @@ class CommodoreGCRParser: public Storage::Disk::Controller {
 				}
 
 				// get sector details, skip if this looks malformed
-				uint8_t checksum = static_cast<uint8_t>(get_next_byte());
-				sector->sector = static_cast<uint8_t>(get_next_byte());
-				sector->track = static_cast<uint8_t>(get_next_byte());
+				uint8_t checksum = uint8_t(get_next_byte());
+				sector->sector = uint8_t(get_next_byte());
+				sector->track = uint8_t(get_next_byte());
 				uint8_t disk_id[2];
-				disk_id[0] = static_cast<uint8_t>(get_next_byte());
-				disk_id[1] = static_cast<uint8_t>(get_next_byte());
+				disk_id[0] = uint8_t(get_next_byte());
+				disk_id[1] = uint8_t(get_next_byte());
 				if(checksum != (sector->sector ^ sector->track ^ disk_id[0] ^ disk_id[1])) continue;
 
 				// look for the following data
@@ -152,12 +154,12 @@ class CommodoreGCRParser: public Storage::Disk::Controller {
 
 				checksum = 0;
 				for(std::size_t c = 0; c < 256; c++) {
-					sector->data[c] = static_cast<uint8_t>(get_next_byte());
+					sector->data[c] = uint8_t(get_next_byte());
 					checksum ^= sector->data[c];
 				}
 
 				if(checksum == get_next_byte()) {
-					uint16_t sector_address = static_cast<uint16_t>((sector->track << 8) | sector->sector);
+					uint16_t sector_address = uint16_t((sector->track << 8) | sector->sector);
 					sector_cache_[sector_address] = sector;
 					return sector;
 				}
@@ -170,7 +172,7 @@ class CommodoreGCRParser: public Storage::Disk::Controller {
 std::vector<File> Analyser::Static::Commodore::GetFiles(const std::shared_ptr<Storage::Disk::Disk> &disk) {
 	std::vector<File> files;
 	CommodoreGCRParser parser;
-	parser.drive->set_disk(disk);
+	parser.set_disk(disk);
 
 	// find any sector whatsoever to establish the current track
 	std::shared_ptr<CommodoreGCRParser::Sector> sector;
@@ -190,7 +192,7 @@ std::vector<File> Analyser::Static::Commodore::GetFiles(const std::shared_ptr<St
 	}
 
 	// parse directory
-	std::size_t header_pointer = static_cast<std::size_t>(-32);
+	std::size_t header_pointer = size_t(-32);
 	while(header_pointer+32+31 < directory.size()) {
 		header_pointer += 32;
 
@@ -214,7 +216,7 @@ std::vector<File> Analyser::Static::Commodore::GetFiles(const std::shared_ptr<St
 		}
 		new_file.name = Storage::Data::Commodore::petscii_from_bytes(&new_file.raw_name[0], 16, false);
 
-		std::size_t number_of_sectors = static_cast<std::size_t>(directory[header_pointer + 0x1e]) + (static_cast<std::size_t>(directory[header_pointer + 0x1f]) << 8);
+		std::size_t number_of_sectors = size_t(directory[header_pointer + 0x1e]) + (size_t(directory[header_pointer + 0x1f]) << 8);
 		new_file.data.reserve((number_of_sectors - 1) * 254 + 252);
 
 		bool is_first_sector = true;
@@ -225,7 +227,7 @@ std::vector<File> Analyser::Static::Commodore::GetFiles(const std::shared_ptr<St
 			next_track = sector->data[0];
 			next_sector = sector->data[1];
 
-			if(is_first_sector) new_file.starting_address = static_cast<uint16_t>(sector->data[2]) | static_cast<uint16_t>(sector->data[3] << 8);
+			if(is_first_sector) new_file.starting_address = uint16_t(sector->data[2]) | uint16_t(sector->data[3] << 8);
 			if(next_track)
 				new_file.data.insert(new_file.data.end(), sector->data.begin() + (is_first_sector ? 4 : 2), sector->data.end());
 			else

Analyser/Static/Commodore/File.cpp

@@ -23,7 +23,7 @@ bool Analyser::Static::Commodore::File::is_basic() {
 	//		... null-terminated code ...
 	//	(with a next line address of 0000 indicating end of program)
 	while(1) {
-		if(static_cast<size_t>(line_address - starting_address) >= data.size() + 2) break;
+		if(size_t(line_address - starting_address) >= data.size() + 2) break;
 
 		uint16_t next_line_address = data[line_address - starting_address];
 		next_line_address |= data[line_address - starting_address + 1] << 8;
@@ -33,13 +33,13 @@ bool Analyser::Static::Commodore::File::is_basic() {
 		}
 		if(next_line_address < line_address + 5) break;
 
-		if(static_cast<size_t>(line_address - starting_address) >= data.size() + 5) break;
+		if(size_t(line_address - starting_address) >= data.size() + 5) break;
 		uint16_t next_line_number = data[line_address - starting_address + 2];
 		next_line_number |= data[line_address - starting_address + 3] << 8;
 
 		if(next_line_number <= line_number) break;
 
-		line_number = static_cast<uint16_t>(next_line_number);
+		line_number = uint16_t(next_line_number);
 		line_address = next_line_address;
 	}
 

Analyser/Static/Commodore/StaticAnalyser.cpp

@@ -16,6 +16,7 @@
 #include "../../../Outputs/Log.hpp"
 
 #include <algorithm>
+#include <cstring>
 #include <sstream>
 
 using namespace Analyser::Static::Commodore;
@@ -41,10 +42,10 @@ static std::vector<std::shared_ptr<Storage::Cartridge::Cartridge>>
 	return vic20_cartridges;
 }
 
-Analyser::Static::TargetList Analyser::Static::Commodore::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms) {
+Analyser::Static::TargetList Analyser::Static::Commodore::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType) {
 	TargetList destination;
 
-	std::unique_ptr<Target> target(new Target);
+	auto target = std::make_unique<Target>();
 	target->machine = Machine::Vic20;	// TODO: machine estimation
 	target->confidence = 0.5; // TODO: a proper estimation
 
@@ -78,7 +79,7 @@ Analyser::Static::TargetList Analyser::Static::Commodore::GetTargets(const Media
 	}
 
 	if(!files.empty()) {
-		target->memory_model = Target::MemoryModel::Unexpanded;
+		auto memory_model = Target::MemoryModel::Unexpanded;
 		std::ostringstream string_stream;
 		string_stream << "LOAD\"" << (is_disk ? "*" : "") << "\"," << device << ",";
 		if(files.front().is_basic()) {
@@ -93,17 +94,20 @@ Analyser::Static::TargetList Analyser::Static::Commodore::GetTargets(const Media
 		switch(files.front().starting_address) {
 			default:
 				LOG("Unrecognised loading address for Commodore program: " << PADHEX(4) <<  files.front().starting_address);
+				[[fallthrough]];
 			case 0x1001:
-				target->memory_model = Target::MemoryModel::Unexpanded;
+				memory_model = Target::MemoryModel::Unexpanded;
 			break;
 			case 0x1201:
-				target->memory_model = Target::MemoryModel::ThirtyTwoKB;
+				memory_model = Target::MemoryModel::ThirtyTwoKB;
 			break;
 			case 0x0401:
-				target->memory_model = Target::MemoryModel::EightKB;
+				memory_model = Target::MemoryModel::EightKB;
 			break;
 		}
 
+		target->set_memory_model(memory_model);
+
 		// General approach: increase memory size conservatively such that the largest file found will fit.
 //		for(File &file : files) {
 //			std::size_t file_size = file.data.size();
@@ -145,13 +149,52 @@ Analyser::Static::TargetList Analyser::Static::Commodore::GetTargets(const Media
 	}
 
 	if(!target->media.empty()) {
-		// Inspect filename for a region hint.
+		// Inspect filename for configuration hints.
 		std::string lowercase_name = file_name;
 		std::transform(lowercase_name.begin(), lowercase_name.end(), lowercase_name.begin(), ::tolower);
+
+		// Hint 1: 'ntsc' anywhere in the name implies America.
 		if(lowercase_name.find("ntsc") != std::string::npos) {
 			target->region = Analyser::Static::Commodore::Target::Region::American;
 		}
 
+		// Potential additional hints: check for TheC64 tags.
+		auto final_underscore = lowercase_name.find_last_of('_');
+		if(final_underscore != std::string::npos) {
+			auto iterator = lowercase_name.begin() + ssize_t(final_underscore) + 1;
+
+			while(iterator != lowercase_name.end()) {
+				// Grab the next tag.
+				char next_tag[3] = {0, 0, 0};
+				next_tag[0] = *iterator++;
+				if(iterator == lowercase_name.end()) break;
+				next_tag[1] = *iterator++;
+
+				// Exit early if attempting to read another tag has run over the file extension.
+				if(next_tag[0] == '.' || next_tag[1] == '.') break;
+
+				// Check whether it's anything.
+				target->enabled_ram.bank0 |= !strcmp(next_tag, "b0");
+				target->enabled_ram.bank1 |= !strcmp(next_tag, "b1");
+				target->enabled_ram.bank2 |= !strcmp(next_tag, "b2");
+				target->enabled_ram.bank3 |= !strcmp(next_tag, "b3");
+				target->enabled_ram.bank5 |= !strcmp(next_tag, "b5");
+				if(!strcmp(next_tag, "tn")) {	// i.e. NTSC.
+					target->region = Analyser::Static::Commodore::Target::Region::American;
+				}
+				if(!strcmp(next_tag, "tp")) {	// i.e. PAL.
+					target->region = Analyser::Static::Commodore::Target::Region::European;
+				}
+
+				// Unhandled:
+				//
+				//	M6: 	this is a C64 file.
+				//	MV: 	this is a Vic-20 file.
+				//	J1/J2:	this C64 file should have the primary joystick in slot 1/2.
+				//	RO:		this disk image should be treated as read-only.
+			}
+		}
+
 		// Attach a 1540 if there are any disks here.
 		target->has_c1540 = !target->media.disks.empty();
 

Analyser/Static/Commodore/Target.hpp

@@ -9,6 +9,8 @@
 #ifndef Analyser_Static_Commodore_Target_h
 #define Analyser_Static_Commodore_Target_h
 
+#include "../../../Reflection/Enum.hpp"
+#include "../../../Reflection/Struct.hpp"
 #include "../StaticAnalyser.hpp"
 #include <string>
 
@@ -16,25 +18,57 @@ namespace Analyser {
 namespace Static {
 namespace Commodore {
 
-struct Target: public ::Analyser::Static::Target {
+struct Target: public Analyser::Static::Target, public Reflection::StructImpl<Target> {
 	enum class MemoryModel {
 		Unexpanded,
 		EightKB,
 		ThirtyTwoKB
 	};
 
-	enum class Region {
+	ReflectableEnum(Region,
 		American,
 		Danish,
 		Japanese,
 		European,
 		Swedish
-	};
+	);
+
+	/// Maps from a named memory model to a bank enabled/disabled set.
+	void set_memory_model(MemoryModel memory_model) {
+		// This is correct for unexpanded and 32kb memory models.
+		enabled_ram.bank0 = enabled_ram.bank1 =
+		enabled_ram.bank2 = enabled_ram.bank3 =
+		enabled_ram.bank5 = memory_model == MemoryModel::ThirtyTwoKB;
+
+		// Bank 0 will need to be enabled if this is an 8kb machine.
+		enabled_ram.bank0 |= memory_model == MemoryModel::EightKB;
+	}
+	struct {
+		bool bank0 = false;
+		bool bank1 = false;
+		bool bank2 = false;
+		bool bank3 = false;
+		bool bank5 = false;
+					// Sic. There is no bank 4; this is because the area that logically would be
+					// bank 4 is occupied by the character ROM, colour RAM, hardware registers, etc.
+	} enabled_ram;
 
-	MemoryModel memory_model = MemoryModel::Unexpanded;
 	Region region = Region::European;
 	bool has_c1540 = false;
 	std::string loading_command;
+
+	Target() : Analyser::Static::Target(Machine::Vic20) {
+		if(needs_declare()) {
+			DeclareField(enabled_ram.bank0);
+			DeclareField(enabled_ram.bank1);
+			DeclareField(enabled_ram.bank2);
+			DeclareField(enabled_ram.bank3);
+			DeclareField(enabled_ram.bank5);
+			DeclareField(region);
+			DeclareField(has_c1540);
+			AnnounceEnum(Region);
+		}
+	}
 };
 
 }

Analyser/Static/Disassembler/6502.cpp

@@ -26,12 +26,12 @@ static void AddToDisassembly(PartialDisassembly &disassembly, const std::vector<
 
 		Instruction instruction;
 		instruction.address = address;
-		address++;
+		++address;
 
-		// get operation
-		uint8_t operation = memory[local_address];
+		// Get operation.
+		const uint8_t operation = memory[local_address];
 
-		// decode addressing mode
+		// Decode addressing mode.
 		switch(operation&0x1f) {
 			case 0x00:
 				if(operation >= 0x80) instruction.addressing_mode = Instruction::Immediate;
@@ -74,7 +74,7 @@ static void AddToDisassembly(PartialDisassembly &disassembly, const std::vector<
 			break;
 		}
 
-		// decode operation
+		// Decode operation.
 #define RM_INSTRUCTION(base, op)	\
 	case base+0x09: case base+0x05: case base+0x15: case base+0x01: case base+0x11: case base+0x0d: case base+0x1d: case base+0x19:	\
 		instruction.operation = op;	\
@@ -222,14 +222,14 @@ static void AddToDisassembly(PartialDisassembly &disassembly, const std::vector<
 #undef M_INSTRUCTION
 #undef IM_INSTRUCTION
 
-		// get operand
+		// Get operand.
 		switch(instruction.addressing_mode) {
-			// zero-byte operands
+			// Zero-byte operands.
 			case Instruction::Implied:
 				instruction.operand = 0;
 			break;
 
-			// one-byte operands
+			// One-byte operands.
 			case Instruction::Immediate:
 			case Instruction::ZeroPage: case Instruction::ZeroPageX: case Instruction::ZeroPageY:
 			case Instruction::IndexedIndirectX: case Instruction::IndirectIndexedY:
@@ -242,7 +242,7 @@ static void AddToDisassembly(PartialDisassembly &disassembly, const std::vector<
 			}
 			break;
 
-			// two-byte operands
+			// Two-byte operands.
 			case Instruction::Absolute: case Instruction::AbsoluteX: case Instruction::AbsoluteY:
 			case Instruction::Indirect: {
 				std::size_t low_operand_address = address_mapper(address);
@@ -250,18 +250,18 @@ static void AddToDisassembly(PartialDisassembly &disassembly, const std::vector<
 				if(low_operand_address >= memory.size() || high_operand_address >= memory.size()) return;
 				address += 2;
 
-				instruction.operand = memory[low_operand_address] | static_cast<uint16_t>(memory[high_operand_address] << 8);
+				instruction.operand = memory[low_operand_address] | uint16_t(memory[high_operand_address] << 8);
 			}
 			break;
 		}
 
-		// store the instruction away
+		// Store the instruction.
 		disassembly.disassembly.instructions_by_address[instruction.address] = instruction;
 
 		// TODO: something wider-ranging than this
 		if(instruction.addressing_mode == Instruction::Absolute || instruction.addressing_mode == Instruction::ZeroPage) {
-			std::size_t mapped_address = address_mapper(instruction.operand);
-			bool is_external = mapped_address >= memory.size();
+			const size_t mapped_address = address_mapper(instruction.operand);
+			const bool is_external = mapped_address >= memory.size();
 
 			switch(instruction.operation) {
 				default: break;
@@ -290,7 +290,7 @@ static void AddToDisassembly(PartialDisassembly &disassembly, const std::vector<
 			}
 		}
 
-		// decide on overall flow control
+		// Decide on overall flow control.
 		if(instruction.operation == Instruction::RTS || instruction.operation == Instruction::RTI) return;
 		if(instruction.operation == Instruction::BRK) return;	// TODO: check whether IRQ vector is within memory range
 		if(instruction.operation == Instruction::JSR) {
@@ -302,7 +302,7 @@ static void AddToDisassembly(PartialDisassembly &disassembly, const std::vector<
 			return;
 		}
 		if(instruction.addressing_mode == Instruction::Relative) {
-			uint16_t destination = static_cast<uint16_t>(address + (int8_t)instruction.operand);
+			uint16_t destination = uint16_t(address + int8_t(instruction.operand));
 			disassembly.remaining_entry_points.push_back(destination);
 		}
 	}

Analyser/Static/Disassembler/AddressMapper.cpp

@@ -1,9 +0,0 @@
-//
-//  AddressMapper.cpp
-//  Clock Signal
-//
-//  Created by Thomas Harte on 30/12/2017.
-//  Copyright 2017 Thomas Harte. All rights reserved.
-//
-
-#include "AddressMapper.hpp"

Analyser/Static/Disassembler/AddressMapper.hpp

@@ -21,7 +21,7 @@ namespace Disassembler {
 */
 template <typename T> std::function<std::size_t(T)> OffsetMapper(T start_address) {
 	return [start_address](T argument) {
-		return static_cast<std::size_t>(argument - start_address);
+		return size_t(argument - start_address);
 	};
 }
 

Analyser/Static/Disassembler/Z80.cpp

@@ -33,7 +33,7 @@ class Accessor {
 		uint16_t word() {
 			uint8_t low = byte();
 			uint8_t high = byte();
-			return static_cast<uint16_t>(low | (high << 8));
+			return uint16_t(low | (high << 8));
 		}
 
 		bool overrun() {
@@ -562,7 +562,7 @@ struct Z80Disassembler {
 			int access_type =
 				((instruction.source == Instruction::Location::Operand_Indirect) ? 1 : 0) |
 				((instruction.destination == Instruction::Location::Operand_Indirect) ? 2 : 0);
-			uint16_t address = static_cast<uint16_t>(instruction.operand);
+			uint16_t address = uint16_t(instruction.operand);
 			bool is_internal = address_mapper(address) < memory.size();
 			switch(access_type) {
 				default: break;
@@ -594,7 +594,7 @@ struct Z80Disassembler {
 				instruction.operation == Instruction::Operation::JR ||
 				instruction.operation == Instruction::Operation::CALL ||
 				instruction.operation == Instruction::Operation::RST) {
-				disassembly.remaining_entry_points.push_back(static_cast<uint16_t>(instruction.operand));
+				disassembly.remaining_entry_points.push_back(uint16_t(instruction.operand));
 			}
 
 			// This is it if: an unconditional RET, RETI, RETN, JP or JR is found.

Analyser/Static/DiskII/StaticAnalyser.cpp

@@ -20,8 +20,7 @@ namespace {
 
 Analyser::Static::Target *AppleTarget(const Storage::Encodings::AppleGCR::Sector *sector_zero) {
 	using Target = Analyser::Static::AppleII::Target;
-	auto *target = new Target;
-	target->machine = Analyser::Machine::AppleII;
+	auto *const target = new Target;
 
 	if(sector_zero && sector_zero->encoding == Storage::Encodings::AppleGCR::Sector::Encoding::FiveAndThree) {
 		target->disk_controller = Target::DiskController::ThirteenSector;
@@ -32,10 +31,9 @@ Analyser::Static::Target *AppleTarget(const Storage::Encodings::AppleGCR::Sector
 	return target;
 }
 
-Analyser::Static::Target *OricTarget(const Storage::Encodings::AppleGCR::Sector *sector_zero) {
+Analyser::Static::Target *OricTarget(const Storage::Encodings::AppleGCR::Sector *) {
 	using Target = Analyser::Static::Oric::Target;
-	auto *target = new Target;
-	target->machine = Analyser::Machine::Oric;
+	auto *const target = new Target;
 	target->rom = Target::ROM::Pravetz;
 	target->disk_interface = Target::DiskInterface::Pravetz;
 	target->loading_command = "CALL 800\n";
@@ -44,13 +42,13 @@ Analyser::Static::Target *OricTarget(const Storage::Encodings::AppleGCR::Sector
 
 }
 
-Analyser::Static::TargetList Analyser::Static::DiskII::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms) {
+Analyser::Static::TargetList Analyser::Static::DiskII::GetTargets(const Media &media, const std::string &, TargetPlatform::IntType) {
 	// This analyser can comprehend disks only.
 	if(media.disks.empty()) return {};
 
 	// Grab track 0, sector 0: the boot sector.
-	auto track_zero = media.disks.front()->get_track_at_position(Storage::Disk::Track::Address(0, Storage::Disk::HeadPosition(0)));
-	auto sector_map = Storage::Encodings::AppleGCR::sectors_from_segment(
+	const auto track_zero = media.disks.front()->get_track_at_position(Storage::Disk::Track::Address(0, Storage::Disk::HeadPosition(0)));
+	const auto sector_map = Storage::Encodings::AppleGCR::sectors_from_segment(
 		Storage::Disk::track_serialisation(*track_zero, Storage::Time(1, 50000)));
 
 	const Storage::Encodings::AppleGCR::Sector *sector_zero = nullptr;
@@ -77,7 +75,7 @@ Analyser::Static::TargetList Analyser::Static::DiskII::GetTargets(const Media &m
 	// If the boot sector looks like it's intended for the Oric, create an Oric.
 	// Otherwise go with the Apple II.
 
-	auto disassembly = Analyser::Static::MOS6502::Disassemble(sector_zero->data, Analyser::Static::Disassembler::OffsetMapper(0xb800), {0xb800});
+	const auto disassembly = Analyser::Static::MOS6502::Disassemble(sector_zero->data, Analyser::Static::Disassembler::OffsetMapper(0xb800), {0xb800});
 
 	bool did_read_shift_register = false;
 	bool is_oric = false;

Analyser/Static/MSX/StaticAnalyser.cpp

@@ -27,15 +27,14 @@ static std::unique_ptr<Analyser::Static::Target> CartridgeTarget(
 	std::vector<Storage::Cartridge::Cartridge::Segment> output_segments;
 	if(segment.data.size() & 0x1fff) {
 		std::vector<uint8_t> truncated_data;
-		std::vector<uint8_t>::difference_type truncated_size = static_cast<std::vector<uint8_t>::difference_type>(segment.data.size()) & ~0x1fff;
+		std::vector<uint8_t>::difference_type truncated_size = std::vector<uint8_t>::difference_type(segment.data.size()) & ~0x1fff;
 		truncated_data.insert(truncated_data.begin(), segment.data.begin(), segment.data.begin() + truncated_size);
 		output_segments.emplace_back(start_address, truncated_data);
 	} else {
 		output_segments.emplace_back(start_address, segment.data);
 	}
 
-	std::unique_ptr<Analyser::Static::MSX::Target> target(new Analyser::Static::MSX::Target);
-	target->machine = Analyser::Machine::MSX;
+	auto target = std::make_unique<Analyser::Static::MSX::Target>();
 	target->confidence = confidence;
 
 	if(type == Analyser::Static::MSX::Cartridge::Type::None) {
@@ -97,7 +96,7 @@ static Analyser::Static::TargetList CartridgeTargetsFrom(
 		// Reject cartridge if the ROM header wasn't found.
 		if(!found_start) continue;
 
-		uint16_t init_address = static_cast<uint16_t>(segment.data[2] | (segment.data[3] << 8));
+		uint16_t init_address = uint16_t(segment.data[2] | (segment.data[3] << 8));
 		// TODO: check for a rational init address?
 
 		// If this ROM is less than 48kb in size then it's an ordinary ROM. Just emplace it and move on.
@@ -147,7 +146,7 @@ static Analyser::Static::TargetList CartridgeTargetsFrom(
 //				) &&
 //				((next_iterator->second.operand >> 13) != (0x4000 >> 13))
 //			) {
-//				const uint16_t address = static_cast<uint16_t>(next_iterator->second.operand);
+//				const uint16_t address = uint16_t(next_iterator->second.operand);
 //				switch(iterator->second.operand) {
 //					case 0x6000:
 //						if(address >= 0x6000 && address < 0x8000) {
@@ -208,13 +207,13 @@ static Analyser::Static::TargetList CartridgeTargetsFrom(
 			if(	instruction_pair.second.operation == Instruction::Operation::LD &&
 				instruction_pair.second.destination == Instruction::Location::Operand_Indirect &&
 				instruction_pair.second.source == Instruction::Location::A) {
-				address_counts[static_cast<uint16_t>(instruction_pair.second.operand)]++;
+				address_counts[uint16_t(instruction_pair.second.operand)]++;
 			}
 		}
 
 		// Weight confidences by number of observed hits.
 		float total_hits =
-			static_cast<float>(
+			float(
 				address_counts[0x6000] + address_counts[0x6800] +
 				address_counts[0x7000] + address_counts[0x7800] +
 				address_counts[0x77ff] + address_counts[0x8000] +
@@ -226,42 +225,42 @@ static Analyser::Static::TargetList CartridgeTargetsFrom(
 			segment,
 			start_address,
 			Analyser::Static::MSX::Cartridge::ASCII8kb,
-			static_cast<float>(	address_counts[0x6000] +
-								address_counts[0x6800] +
-								address_counts[0x7000] +
-								address_counts[0x7800]) / total_hits));
+			float(	address_counts[0x6000] +
+					address_counts[0x6800] +
+					address_counts[0x7000] +
+					address_counts[0x7800]) / total_hits));
 		targets.push_back(CartridgeTarget(
 			segment,
 			start_address,
 			Analyser::Static::MSX::Cartridge::ASCII16kb,
-			static_cast<float>(	address_counts[0x6000] +
-								address_counts[0x7000] +
-								address_counts[0x77ff]) / total_hits));
+			float(	address_counts[0x6000] +
+					address_counts[0x7000] +
+					address_counts[0x77ff]) / total_hits));
 		if(!is_ascii) {
 			targets.push_back(CartridgeTarget(
 				segment,
 				start_address,
 				Analyser::Static::MSX::Cartridge::Konami,
-				static_cast<float>(	address_counts[0x6000] +
-									address_counts[0x8000] +
-									address_counts[0xa000]) / total_hits));
+				float(	address_counts[0x6000] +
+						address_counts[0x8000] +
+						address_counts[0xa000]) / total_hits));
 		}
 		if(!is_ascii) {
 			targets.push_back(CartridgeTarget(
 				segment,
 				start_address,
 				Analyser::Static::MSX::Cartridge::KonamiWithSCC,
-				static_cast<float>(	address_counts[0x5000] +
-									address_counts[0x7000] +
-									address_counts[0x9000] +
-									address_counts[0xb000]) / total_hits));
+				float(	address_counts[0x5000] +
+						address_counts[0x7000] +
+						address_counts[0x9000] +
+						address_counts[0xb000]) / total_hits));
 		}
 	}
 
 	return targets;
 }
 
-Analyser::Static::TargetList Analyser::Static::MSX::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms) {
+Analyser::Static::TargetList Analyser::Static::MSX::GetTargets(const Media &media, const std::string &, TargetPlatform::IntType) {
 	TargetList destination;
 
 	// Append targets for any cartridges that look correct.
@@ -269,7 +268,7 @@ Analyser::Static::TargetList Analyser::Static::MSX::GetTargets(const Media &medi
 	std::move(cartridge_targets.begin(), cartridge_targets.end(), std::back_inserter(destination));
 
 	// Consider building a target for disks and/or tapes.
-	std::unique_ptr<Target> target(new Target);
+	auto target = std::make_unique<Target>();
 
 	// Check tapes for loadable files.
 	for(auto &tape : media.tapes) {
@@ -295,7 +294,6 @@ Analyser::Static::TargetList Analyser::Static::MSX::GetTargets(const Media &medi
 	target->has_disk_drive = !media.disks.empty();
 
 	if(!target->media.empty()) {
-		target->machine = Machine::MSX;
 		target->confidence = 0.5;
 		destination.push_back(std::move(target));
 	}

Analyser/Static/MSX/Tape.cpp

@@ -44,7 +44,7 @@ std::vector<File> Analyser::Static::MSX::GetFiles(const std::shared_ptr<Storage:
 		for(std::size_t c = 0; c < sizeof(header); ++c) {
 			int next_byte = Parser::get_byte(*file_speed, tape_player);
 			if(next_byte == -1) break;
-			header[c] = static_cast<uint8_t>(next_byte);
+			header[c] = uint8_t(next_byte);
 		}
 
 		bool bytes_are_same = true;
@@ -67,7 +67,7 @@ std::vector<File> Analyser::Static::MSX::GetFiles(const std::shared_ptr<Storage:
 		// Read file name.
 		char name[7];
 		for(std::size_t c = 1; c < 6; ++c)
-			name[c] = static_cast<char>(Parser::get_byte(*file_speed, tape_player));
+			name[c] = char(Parser::get_byte(*file_speed, tape_player));
 		name[6] = '\0';
 		file.name = name;
 
@@ -82,7 +82,7 @@ std::vector<File> Analyser::Static::MSX::GetFiles(const std::shared_ptr<Storage:
 					int byte = Parser::get_byte(*file_speed, tape_player);
 					if(byte == -1) break;
 					contains_end_of_file |= (byte == 0x1a);
-					file.data.push_back(static_cast<uint8_t>(byte));
+					file.data.push_back(uint8_t(byte));
 				}
 				if(c != -1) break;
 				if(contains_end_of_file) {
@@ -105,13 +105,13 @@ std::vector<File> Analyser::Static::MSX::GetFiles(const std::shared_ptr<Storage:
 			for(c = 0; c < sizeof(locations); ++c) {
 				int byte = Parser::get_byte(*file_speed, tape_player);
 				if(byte == -1) break;
-				locations[c] = static_cast<uint8_t>(byte);
+				locations[c] = uint8_t(byte);
 			}
 			if(c != sizeof(locations)) continue;
 
-			file.starting_address = static_cast<uint16_t>(locations[0] | (locations[1] << 8));
-			end_address = static_cast<uint16_t>(locations[2] | (locations[3] << 8));
-			file.entry_address = static_cast<uint16_t>(locations[4] | (locations[5] << 8));
+			file.starting_address = uint16_t(locations[0] | (locations[1] << 8));
+			end_address = uint16_t(locations[2] | (locations[3] << 8));
+			file.entry_address = uint16_t(locations[4] | (locations[5] << 8));
 
 			if(end_address < file.starting_address) continue;
 
@@ -119,7 +119,7 @@ std::vector<File> Analyser::Static::MSX::GetFiles(const std::shared_ptr<Storage:
 			while(length--) {
 				int byte = Parser::get_byte(*file_speed, tape_player);
 				if(byte == -1) continue;
-				file.data.push_back(static_cast<uint8_t>(byte));
+				file.data.push_back(uint8_t(byte));
 			}
 
 			files.push_back(std::move(file));
@@ -135,10 +135,10 @@ std::vector<File> Analyser::Static::MSX::GetFiles(const std::shared_ptr<Storage:
 			next_address_buffer[1] = Parser::get_byte(*file_speed, tape_player);
 
 			if(next_address_buffer[0] == -1 || next_address_buffer[1] == -1) break;
-			file.data.push_back(static_cast<uint8_t>(next_address_buffer[0]));
-			file.data.push_back(static_cast<uint8_t>(next_address_buffer[1]));
+			file.data.push_back(uint8_t(next_address_buffer[0]));
+			file.data.push_back(uint8_t(next_address_buffer[1]));
 
-			uint16_t next_address = static_cast<uint16_t>(next_address_buffer[0] | (next_address_buffer[1] << 8));
+			uint16_t next_address = uint16_t(next_address_buffer[0] | (next_address_buffer[1] << 8));
 			if(!next_address) {
 				files.push_back(std::move(file));
 				break;
@@ -155,7 +155,7 @@ std::vector<File> Analyser::Static::MSX::GetFiles(const std::shared_ptr<Storage:
 					found_error = true;
 					break;
 				}
-				file.data.push_back(static_cast<uint8_t>(byte));
+				file.data.push_back(uint8_t(byte));
 			}
 			if(found_error) break;
 		}

Analyser/Static/MSX/Target.hpp

@@ -9,6 +9,8 @@
 #ifndef Analyser_Static_MSX_Target_h
 #define Analyser_Static_MSX_Target_h
 
+#include "../../../Reflection/Enum.hpp"
+#include "../../../Reflection/Struct.hpp"
 #include "../StaticAnalyser.hpp"
 #include <string>
 
@@ -16,15 +18,24 @@ namespace Analyser {
 namespace Static {
 namespace MSX {
 
-struct Target: public ::Analyser::Static::Target {
+struct Target: public ::Analyser::Static::Target, public Reflection::StructImpl<Target> {
 	bool has_disk_drive = false;
 	std::string loading_command;
 
-	enum class Region {
+	ReflectableEnum(Region,
 		Japan,
 		USA,
 		Europe
-	} region = Region::USA;
+	);
+	Region region = Region::USA;
+
+	Target(): Analyser::Static::Target(Machine::MSX) {
+		if(needs_declare()) {
+			DeclareField(has_disk_drive);
+			DeclareField(region);
+			AnnounceEnum(Region);
+		}
+	}
 };
 
 }

Analyser/Static/Macintosh/StaticAnalyser.cpp

@@ -9,16 +9,15 @@
 #include "StaticAnalyser.hpp"
 #include "Target.hpp"
 
-Analyser::Static::TargetList Analyser::Static::Macintosh::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms) {
-	// This analyser can comprehend disks only.
-	if(media.disks.empty()) return {};
+Analyser::Static::TargetList Analyser::Static::Macintosh::GetTargets(const Media &media, const std::string &, TargetPlatform::IntType) {
+	// This analyser can comprehend disks and mass-storage devices only.
+	if(media.disks.empty() && media.mass_storage_devices.empty()) return {};
 
-	// If there is at least one disk, wave it through.
+	// As there is at least one usable media image, wave it through.
 	Analyser::Static::TargetList targets;
 
 	using Target = Analyser::Static::Macintosh::Target;
-	auto *target = new Target;
-	target->machine = Analyser::Machine::Macintosh;
+	auto *const target = new Target;
 	target->media = media;
 	targets.push_back(std::unique_ptr<Analyser::Static::Target>(target));
 

Analyser/Static/Macintosh/Target.hpp

@@ -9,19 +9,25 @@
 #ifndef Analyser_Static_Macintosh_Target_h
 #define Analyser_Static_Macintosh_Target_h
 
+#include "../../../Reflection/Enum.hpp"
+#include "../../../Reflection/Struct.hpp"
+#include "../StaticAnalyser.hpp"
+
 namespace Analyser {
 namespace Static {
 namespace Macintosh {
 
-struct Target: public ::Analyser::Static::Target {
-	enum class Model {
-		Mac128k,
-		Mac512k,
-		Mac512ke,
-		MacPlus
-	};
+struct Target: public Analyser::Static::Target, public Reflection::StructImpl<Target> {
+	ReflectableEnum(Model, Mac128k, Mac512k, Mac512ke, MacPlus);
+	Model model = Model::MacPlus;
 
-	Model model = Model::Mac512ke;
+	Target() : Analyser::Static::Target(Machine::Macintosh) {
+		// Boilerplate for declaring fields and potential values.
+		if(needs_declare()) {
+			DeclareField(model);
+			AnnounceEnum(Model);
+		}
+	}
 };
 
 }

Analyser/Static/Oric/StaticAnalyser.cpp

@@ -20,7 +20,9 @@
 
 using namespace Analyser::Static::Oric;
 
-static int Score(const Analyser::Static::MOS6502::Disassembly &disassembly, const std::set<uint16_t> &rom_functions, const std::set<uint16_t> &variable_locations) {
+namespace {
+
+int score(const Analyser::Static::MOS6502::Disassembly &disassembly, const std::set<uint16_t> &rom_functions, const std::set<uint16_t> &variable_locations) {
 	int score = 0;
 
 	for(const auto address : disassembly.outward_calls)		score += (rom_functions.find(address) != rom_functions.end()) ? 1 : -1;
@@ -30,7 +32,7 @@ static int Score(const Analyser::Static::MOS6502::Disassembly &disassembly, cons
 	return score;
 }
 
-static int Basic10Score(const Analyser::Static::MOS6502::Disassembly &disassembly) {
+int basic10_score(const Analyser::Static::MOS6502::Disassembly &disassembly) {
 	const std::set<uint16_t> rom_functions = {
 		0x0228,	0x022b,
 		0xc3ca,	0xc3f8,	0xc448,	0xc47c,	0xc4b5,	0xc4e3,	0xc4e0,	0xc524,	0xc56f,	0xc5a2,	0xc5f8,	0xc60a,	0xc6a5,	0xc6de,	0xc719,	0xc738,
@@ -51,10 +53,10 @@ static int Basic10Score(const Analyser::Static::MOS6502::Disassembly &disassembl
 		0x0228, 0x0229, 0x022a, 0x022b, 0x022c, 0x022d, 0x0230
 	};
 
-	return Score(disassembly, rom_functions, variable_locations);
+	return score(disassembly, rom_functions, variable_locations);
 }
 
-static int Basic11Score(const Analyser::Static::MOS6502::Disassembly &disassembly) {
+int basic11_score(const Analyser::Static::MOS6502::Disassembly &disassembly) {
 	const std::set<uint16_t> rom_functions = {
 		0x0238,	0x023b,	0x023e,	0x0241,	0x0244,	0x0247,
 		0xc3c6,	0xc3f4,	0xc444,	0xc47c,	0xc4a8,	0xc4d3,	0xc4e0,	0xc524,	0xc55f,	0xc592,	0xc5e8,	0xc5fa,	0xc692,	0xc6b3,	0xc6ee,	0xc70d,
@@ -76,10 +78,10 @@ static int Basic11Score(const Analyser::Static::MOS6502::Disassembly &disassembl
 		0x0244, 0x0245, 0x0246, 0x0247, 0x0248, 0x0249, 0x024a, 0x024b, 0x024c
 	};
 
-	return Score(disassembly, rom_functions, variable_locations);
+	return score(disassembly, rom_functions, variable_locations);
 }
 
-static bool IsMicrodisc(Storage::Encodings::MFM::Parser &parser) {
+bool is_microdisc(Storage::Encodings::MFM::Parser &parser) {
 	/*
 		The Microdisc boot sector is sector 2 of track 0 and contains a 23-byte signature.
 	*/
@@ -100,9 +102,51 @@ static bool IsMicrodisc(Storage::Encodings::MFM::Parser &parser) {
 	return !std::memcmp(signature, first_sample.data(), sizeof(signature));
 }
 
-Analyser::Static::TargetList Analyser::Static::Oric::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms) {
-	std::unique_ptr<Target> target(new Target);
-	target->machine = Machine::Oric;
+bool is_400_loader(Storage::Encodings::MFM::Parser &parser, uint16_t range_start, uint16_t range_end) {
+	/*
+		Both the Jasmin and BD-DOS boot sectors are sector 1 of track 0 and are loaded at $400;
+		use disassembly to test for likely matches.
+	*/
+
+	Storage::Encodings::MFM::Sector *sector = parser.get_sector(0, 0, 1);
+	if(!sector) return false;
+	if(sector->samples.empty()) return false;
+
+	// Take a copy of the first sampling, and keep only the final 256 bytes (assuming at least that many were found).
+	std::vector<uint8_t> first_sample = sector->samples[0];
+	if(first_sample.size() < 256) return false;
+	if(first_sample.size() > 256) {
+		first_sample.erase(first_sample.end() - 256, first_sample.end());
+	}
+
+	// Grab a disassembly.
+	const auto disassembly =
+		Analyser::Static::MOS6502::Disassemble(first_sample, Analyser::Static::Disassembler::OffsetMapper(0x400), {0x400});
+
+	// Check for references to the Jasmin registers.
+	int register_hits = 0;
+	for(auto list : {disassembly.external_stores, disassembly.external_loads, disassembly.external_modifies}) {
+		for(auto address : list) {
+			register_hits += (address >= range_start && address <= range_end);
+		}
+	}
+
+	// Arbitrary, sure, but as long as at least two accesses to the requested register range are found, accept this.
+	return register_hits >= 2;
+}
+
+bool is_jasmin(Storage::Encodings::MFM::Parser &parser) {
+	return is_400_loader(parser, 0x3f4, 0x3ff);
+}
+
+bool is_bd500(Storage::Encodings::MFM::Parser &parser) {
+	return is_400_loader(parser, 0x310, 0x323);
+}
+
+}
+
+Analyser::Static::TargetList Analyser::Static::Oric::GetTargets(const Media &media, const std::string &, TargetPlatform::IntType) {
+	auto target = std::make_unique<Target>();
 	target->confidence = 0.5;
 
 	int basic10_votes = 0;
@@ -115,12 +159,10 @@ Analyser::Static::TargetList Analyser::Static::Oric::GetTargets(const Media &med
 			for(const auto &file : tape_files) {
 				if(file.data_type == File::MachineCode) {
 					std::vector<uint16_t> entry_points = {file.starting_address};
-					Analyser::Static::MOS6502::Disassembly disassembly =
+					const Analyser::Static::MOS6502::Disassembly disassembly =
 						Analyser::Static::MOS6502::Disassemble(file.data, Analyser::Static::Disassembler::OffsetMapper(file.starting_address), entry_points);
 
-					int basic10_score = Basic10Score(disassembly);
-					int basic11_score = Basic11Score(disassembly);
-					if(basic10_score > basic11_score) basic10_votes++; else basic11_votes++;
+					if(basic10_score(disassembly) > basic11_score(disassembly)) ++basic10_votes; else ++basic11_votes;
 				}
 			}
 
@@ -130,12 +172,22 @@ Analyser::Static::TargetList Analyser::Static::Oric::GetTargets(const Media &med
 	}
 
 	if(!media.disks.empty()) {
-		// Only the Microdisc is emulated right now, so accept only disks that it can boot from.
+		// 8-DOS is recognised by a dedicated Disk II analyser, so check only for Microdisc,
+		// Jasmin and BD-DOS formats here.
 		for(auto &disk: media.disks) {
 			Storage::Encodings::MFM::Parser parser(true, disk);
-			if(IsMicrodisc(parser)) {
+
+			if(is_microdisc(parser)) {
 				target->disk_interface = Target::DiskInterface::Microdisc;
 				target->media.disks.push_back(disk);
+			} else if(is_jasmin(parser)) {
+				target->disk_interface = Target::DiskInterface::Jasmin;
+				target->should_start_jasmin = true;
+				target->media.disks.push_back(disk);
+			} else if(is_bd500(parser)) {
+				target->disk_interface = Target::DiskInterface::BD500;
+				target->media.disks.push_back(disk);
+				target->rom = Target::ROM::BASIC10;
 			}
 		}
 	}

Analyser/Static/Oric/Tape.cpp

@@ -49,10 +49,10 @@ std::vector<File> Analyser::Static::Oric::GetFiles(const std::shared_ptr<Storage
 		}
 
 		// read end and start addresses
-		new_file.ending_address = static_cast<uint16_t>(parser.get_next_byte(tape, is_fast) << 8);
-		new_file.ending_address |= static_cast<uint16_t>(parser.get_next_byte(tape, is_fast));
-		new_file.starting_address = static_cast<uint16_t>(parser.get_next_byte(tape, is_fast) << 8);
-		new_file.starting_address |= static_cast<uint16_t>(parser.get_next_byte(tape, is_fast));
+		new_file.ending_address = uint16_t(parser.get_next_byte(tape, is_fast) << 8);
+		new_file.ending_address |= uint16_t(parser.get_next_byte(tape, is_fast));
+		new_file.starting_address = uint16_t(parser.get_next_byte(tape, is_fast) << 8);
+		new_file.starting_address |= uint16_t(parser.get_next_byte(tape, is_fast));
 
 		// skip an empty byte
 		parser.get_next_byte(tape, is_fast);
@@ -61,7 +61,7 @@ std::vector<File> Analyser::Static::Oric::GetFiles(const std::shared_ptr<Storage
 		char file_name[17];
 		int name_pos = 0;
 		while(name_pos < 16) {
-			file_name[name_pos] = (char)parser.get_next_byte(tape, is_fast);
+			file_name[name_pos] = char(parser.get_next_byte(tape, is_fast));
 			if(!file_name[name_pos]) break;
 			name_pos++;
 		}
@@ -72,7 +72,7 @@ std::vector<File> Analyser::Static::Oric::GetFiles(const std::shared_ptr<Storage
 		std::size_t body_length = new_file.ending_address - new_file.starting_address + 1;
 		new_file.data.reserve(body_length);
 		for(std::size_t c = 0; c < body_length; c++) {
-			new_file.data.push_back(static_cast<uint8_t>(parser.get_next_byte(tape, is_fast)));
+			new_file.data.push_back(uint8_t(parser.get_next_byte(tape, is_fast)));
 		}
 
 		// only one validation check: was there enough tape?

Analyser/Static/Oric/Target.hpp

@@ -9,6 +9,8 @@
 #ifndef Analyser_Static_Oric_Target_h
 #define Analyser_Static_Oric_Target_h
 
+#include "../../../Reflection/Enum.hpp"
+#include "../../../Reflection/Struct.hpp"
 #include "../StaticAnalyser.hpp"
 #include <string>
 
@@ -16,22 +18,42 @@ namespace Analyser {
 namespace Static {
 namespace Oric {
 
-struct Target: public ::Analyser::Static::Target {
-	enum class ROM {
+struct Target: public Analyser::Static::Target, public Reflection::StructImpl<Target> {
+	ReflectableEnum(ROM,
 		BASIC10,
 		BASIC11,
 		Pravetz
-	};
+	);
 
-	enum class DiskInterface {
+	ReflectableEnum(DiskInterface,
+		None,
 		Microdisc,
 		Pravetz,
-		None
-	};
+		Jasmin,
+		BD500
+	);
+
+	ReflectableEnum(Processor,
+		MOS6502,
+		WDC65816
+	);
 
 	ROM rom = ROM::BASIC11;
 	DiskInterface disk_interface = DiskInterface::None;
+	Processor processor = Processor::MOS6502;
 	std::string loading_command;
+	bool should_start_jasmin = false;
+
+	Target(): Analyser::Static::Target(Machine::Oric) {
+		if(needs_declare()) {
+			DeclareField(rom);
+			DeclareField(disk_interface);
+			DeclareField(processor);
+			AnnounceEnum(ROM);
+			AnnounceEnum(DiskInterface);
+			AnnounceEnum(Processor);
+		}
+	}
 };
 
 }

Analyser/Static/Sega/StaticAnalyser.cpp

@@ -13,14 +13,12 @@
 #include <algorithm>
 #include <cstring>
 
-Analyser::Static::TargetList Analyser::Static::Sega::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms) {
+Analyser::Static::TargetList Analyser::Static::Sega::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType) {
 	if(media.cartridges.empty())
 		return {};
 
 	TargetList targets;
-	std::unique_ptr<Target> target(new Target);
-
-	target->machine = Machine::MasterSystem;
+	auto target = std::make_unique<Target>();
 
 	// Files named .sg are treated as for the SG1000; otherwise assume a Master System.
 	if(file_name.size() >= 2 && *(file_name.end() - 2) == 's' && *(file_name.end() - 1) == 'g') {

Analyser/Static/Sega/Target.hpp

@@ -9,23 +9,27 @@
 #ifndef Analyser_Static_Sega_Target_h
 #define Analyser_Static_Sega_Target_h
 
+#include "../../../Reflection/Enum.hpp"
+#include "../../../Reflection/Struct.hpp"
+#include "../StaticAnalyser.hpp"
+
 namespace Analyser {
 namespace Static {
 namespace Sega {
 
-struct Target: public ::Analyser::Static::Target {
+struct Target: public Analyser::Static::Target, public Reflection::StructImpl<Target> {
 	enum class Model {
 		SG1000,
 		MasterSystem,
 		MasterSystem2,
 	};
 
-	enum class Region {
+	ReflectableEnum(Region,
 		Japan,
 		USA,
 		Europe,
 		Brazil
-	};
+	);
 
 	enum class PagingScheme {
 		Sega,
@@ -35,6 +39,13 @@ struct Target: public ::Analyser::Static::Target {
 	Model model = Model::MasterSystem;
 	Region region = Region::Japan;
 	PagingScheme paging_scheme = PagingScheme::Sega;
+
+	Target() : Analyser::Static::Target(Machine::MasterSystem) {
+		if(needs_declare()) {
+			DeclareField(region);
+			AnnounceEnum(Region);
+		}
+	}
 };
 
 #define is_master_system(v) v >= Analyser::Static::Sega::Target::Model::MasterSystem

Analyser/Static/StaticAnalyser.cpp

@@ -17,7 +17,8 @@
 #include "Acorn/StaticAnalyser.hpp"
 #include "AmstradCPC/StaticAnalyser.hpp"
 #include "AppleII/StaticAnalyser.hpp"
-#include "Atari/StaticAnalyser.hpp"
+#include "Atari2600/StaticAnalyser.hpp"
+#include "AtariST/StaticAnalyser.hpp"
 #include "Coleco/StaticAnalyser.hpp"
 #include "Commodore/StaticAnalyser.hpp"
 #include "DiskII/StaticAnalyser.hpp"
@@ -40,12 +41,18 @@
 #include "../../Storage/Disk/DiskImage/Formats/G64.hpp"
 #include "../../Storage/Disk/DiskImage/Formats/DMK.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"
+#include "../../Storage/Disk/DiskImage/Formats/ST.hpp"
+#include "../../Storage/Disk/DiskImage/Formats/STX.hpp"
 #include "../../Storage/Disk/DiskImage/Formats/WOZ.hpp"
 
+// Mass Storage Devices (i.e. usually, hard disks)
+#include "../../Storage/MassStorage/Formats/HFV.hpp"
+
 // Tapes
 #include "../../Storage/Tape/Formats/CAS.hpp"
 #include "../../Storage/Tape/Formats/CommodoreTAP.hpp"
@@ -100,9 +107,13 @@ static Media GetMediaAndPlatforms(const std::string &file_name, TargetPlatform::
 	Format("dmk", result.disks, Disk::DiskImageHolder<Storage::Disk::DMK>, TargetPlatform::MSX)					// DMK
 	Format("do", result.disks, Disk::DiskImageHolder<Storage::Disk::AppleDSK>, TargetPlatform::DiskII)			// DO
 	Format("dsd", result.disks, Disk::DiskImageHolder<Storage::Disk::SSD>, TargetPlatform::Acorn)				// DSD
-	Format("dsk", result.disks, Disk::DiskImageHolder<Storage::Disk::CPCDSK>, TargetPlatform::AmstradCPC)		// DSK (Amstrad CPC)
+	Format(	"dsk",
+			result.disks,
+			Disk::DiskImageHolder<Storage::Disk::CPCDSK>,
+			TargetPlatform::AmstradCPC | TargetPlatform::Oric)													// DSK (Amstrad CPC)
 	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)
+	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.disks, Disk::DiskImageHolder<Storage::Disk::OricMFMDSK>, TargetPlatform::Oric)			// DSK (Oric)
 	Format("g64", result.disks, Disk::DiskImageHolder<Storage::Disk::G64>, TargetPlatform::Commodore)			// G64
@@ -113,6 +124,7 @@ 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("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
 	Format("p", result.tapes, Tape::ZX80O81P, TargetPlatform::ZX8081)											// P
@@ -138,6 +150,8 @@ static Media GetMediaAndPlatforms(const std::string &file_name, TargetPlatform::
 	Format("sg", result.cartridges, Cartridge::BinaryDump, TargetPlatform::Sega)								// SG
 	Format("sms", result.cartridges, Cartridge::BinaryDump, TargetPlatform::Sega)								// SMS
 	Format("ssd", result.disks, Disk::DiskImageHolder<Storage::Disk::SSD>, TargetPlatform::Acorn)				// SSD
+	Format("st", result.disks, Disk::DiskImageHolder<Storage::Disk::ST>, TargetPlatform::AtariST)				// ST
+	Format("stx", result.disks, Disk::DiskImageHolder<Storage::Disk::STX>, TargetPlatform::AtariST)				// STX
 	Format("tap", result.tapes, Tape::CommodoreTAP, TargetPlatform::Commodore)									// TAP (Commodore)
 	Format("tap", result.tapes, Tape::OricTAP, TargetPlatform::Oric)											// TAP (Oric)
 	Format("tsx", result.tapes, Tape::TZX, TargetPlatform::MSX)													// TSX
@@ -160,7 +174,7 @@ Media Analyser::Static::GetMedia(const std::string &file_name) {
 TargetList Analyser::Static::GetTargets(const std::string &file_name) {
 	TargetList targets;
 
-	// Collect all disks, tapes and ROMs as can be extrapolated from this file, forming the
+	// 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);
@@ -174,7 +188,8 @@ TargetList Analyser::Static::GetTargets(const std::string &file_name) {
 	if(potential_platforms & TargetPlatform::Acorn)			Append(Acorn);
 	if(potential_platforms & TargetPlatform::AmstradCPC)	Append(AmstradCPC);
 	if(potential_platforms & TargetPlatform::AppleII)		Append(AppleII);
-	if(potential_platforms & TargetPlatform::Atari2600)		Append(Atari);
+	if(potential_platforms & TargetPlatform::Atari2600)		Append(Atari2600);
+	if(potential_platforms & TargetPlatform::AtariST)		Append(AtariST);
 	if(potential_platforms & TargetPlatform::ColecoVision)	Append(Coleco);
 	if(potential_platforms & TargetPlatform::Commodore)		Append(Commodore);
 	if(potential_platforms & TargetPlatform::DiskII)		Append(DiskII);

Analyser/Static/StaticAnalyser.hpp

@@ -11,9 +11,10 @@
 
 #include "../Machines.hpp"
 
-#include "../../Storage/Tape/Tape.hpp"
-#include "../../Storage/Disk/Disk.hpp"
 #include "../../Storage/Cartridge/Cartridge.hpp"
+#include "../../Storage/Disk/Disk.hpp"
+#include "../../Storage/MassStorage/MassStorageDevice.hpp"
+#include "../../Storage/Tape/Tape.hpp"
 
 #include <memory>
 #include <string>
@@ -29,9 +30,20 @@ struct Media {
 	std::vector<std::shared_ptr<Storage::Disk::Disk>> disks;
 	std::vector<std::shared_ptr<Storage::Tape::Tape>> tapes;
 	std::vector<std::shared_ptr<Storage::Cartridge::Cartridge>> cartridges;
+	std::vector<std::shared_ptr<Storage::MassStorage::MassStorageDevice>> mass_storage_devices;
 
 	bool empty() const {
-		return disks.empty() && tapes.empty() && cartridges.empty();
+		return disks.empty() && tapes.empty() && cartridges.empty() && mass_storage_devices.empty();
+	}
+
+	Media &operator +=(const Media &rhs) {
+#define append(name)	name.insert(name.end(), rhs.name.begin(), rhs.name.end());
+		append(disks);
+		append(tapes);
+		append(cartridges);
+		append(mass_storage_devices);
+#undef append
+		return *this;
 	}
 };
 
@@ -40,11 +52,12 @@ struct Media {
 	and instructions on how to launch the software attached, plus a measure of confidence in this target's correctness.
 */
 struct Target {
+	Target(Machine machine) : machine(machine) {}
 	virtual ~Target() {}
 
 	Machine machine;
 	Media media;
-	float confidence;
+	float confidence = 0.0f;
 };
 typedef std::vector<std::unique_ptr<Target>> TargetList;
 

Analyser/Static/ZX8081/StaticAnalyser.cpp

@@ -28,13 +28,13 @@ static std::vector<Storage::Data::ZX8081::File> GetFiles(const std::shared_ptr<S
 	return files;
 }
 
-Analyser::Static::TargetList Analyser::Static::ZX8081::GetTargets(const Media &media, const std::string &file_name, TargetPlatform::IntType potential_platforms) {
+Analyser::Static::TargetList Analyser::Static::ZX8081::GetTargets(const Media &media, const std::string &, TargetPlatform::IntType potential_platforms) {
 	TargetList destination;
 	if(!media.tapes.empty()) {
 		std::vector<Storage::Data::ZX8081::File> files = GetFiles(media.tapes.front());
 		media.tapes.front()->reset();
 		if(!files.empty()) {
-			Target *target = new Target;
+			Target *const target = new Target;
 			destination.push_back(std::unique_ptr<::Analyser::Static::Target>(target));
 			target->machine = Machine::ZX8081;
 

Analyser/Static/ZX8081/Target.hpp

@@ -9,6 +9,8 @@
 #ifndef Analyser_Static_ZX8081_Target_h
 #define Analyser_Static_ZX8081_Target_h
 
+#include "../../../Reflection/Enum.hpp"
+#include "../../../Reflection/Struct.hpp"
 #include "../StaticAnalyser.hpp"
 #include <string>
 
@@ -16,17 +18,26 @@ namespace Analyser {
 namespace Static {
 namespace ZX8081 {
 
-struct Target: public ::Analyser::Static::Target {
-	enum class MemoryModel {
+struct Target: public ::Analyser::Static::Target, public Reflection::StructImpl<Target> {
+	ReflectableEnum(MemoryModel,
 		Unexpanded,
 		SixteenKB,
 		SixtyFourKB
-	};
+	);
 
 	MemoryModel memory_model = MemoryModel::Unexpanded;
 	bool is_ZX81 = false;
 	bool ZX80_uses_ZX81_ROM = false;
 	std::string loading_command;
+
+	Target(): Analyser::Static::Target(Machine::ZX8081) {
+		if(needs_declare()) {
+			DeclareField(memory_model);
+			DeclareField(is_ZX81);
+			DeclareField(ZX80_uses_ZX81_ROM);
+			AnnounceEnum(MemoryModel);
+		}
+	}
 };
 
 }

ClockReceiver/ClockReceiver.hpp

@@ -10,6 +10,7 @@
 #define ClockReceiver_hpp
 
 #include "ForceInline.hpp"
+#include <cstdint>
 
 /*
 	Informal pattern for all classes that run from a clock cycle:
@@ -54,7 +55,9 @@
 */
 template <class T> class WrappedInt {
 	public:
-		forceinline constexpr WrappedInt(int l) noexcept : length_(l) {}
+		using IntType = int64_t;
+
+		forceinline constexpr WrappedInt(IntType l) noexcept : length_(l) {}
 		forceinline constexpr WrappedInt() noexcept : length_(0) {}
 
 		forceinline T &operator =(const T &rhs) {
@@ -133,16 +136,20 @@ template <class T> class WrappedInt {
 		forceinline constexpr bool operator !() const					{	return !length_;					}
 		// bool operator () is not supported because it offers an implicit cast to int, which is prone silently to permit misuse
 
-		forceinline constexpr int as_int() const { return length_; }
+		/// @returns The underlying int, cast to an integral type of your choosing.
+		template<typename Type = IntType> forceinline constexpr Type as() const { return Type(length_); }
+
+		/// @returns The underlying int, in its native form.
+		forceinline constexpr IntType as_integral() const { return length_; }
 
 		/*!
 			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.
 		*/
-		forceinline T divide(const T &divisor) {
-			T result(length_ / divisor.length_);
-			length_ %= divisor.length_;
-			return result;
+		template <typename Result = T> forceinline Result divide(const T &divisor) {
+			Result r;
+			static_cast<T *>(this)->fill(r, divisor);
+			return r;
 		}
 
 		/*!
@@ -161,15 +168,14 @@ template <class T> class WrappedInt {
 		// classes that use this template.
 
 	protected:
-		int length_;
+		IntType length_;
 };
 
 /// Describes an integer number of whole cycles: pairs of clock signal transitions.
 class Cycles: public WrappedInt<Cycles> {
 	public:
-		forceinline constexpr Cycles(int l) noexcept : WrappedInt<Cycles>(l) {}
+		forceinline constexpr Cycles(IntType l) noexcept : WrappedInt<Cycles>(l) {}
 		forceinline constexpr Cycles() noexcept : WrappedInt<Cycles>() {}
-		forceinline constexpr Cycles(const Cycles &cycles) noexcept : WrappedInt<Cycles>(cycles.length_) {}
 
 	private:
 		friend WrappedInt;
@@ -177,16 +183,20 @@ class Cycles: public WrappedInt<Cycles> {
 			result.length_ = length_;
 			length_ = 0;
 		}
+
+		void fill(Cycles &result, const Cycles &divisor) {
+			result.length_ = length_ / divisor.length_;
+			length_ %= divisor.length_;
+		}
 };
 
 /// Describes an integer number of half cycles: single clock signal transitions.
 class HalfCycles: public WrappedInt<HalfCycles> {
 	public:
-		forceinline constexpr HalfCycles(int l) noexcept : WrappedInt<HalfCycles>(l) {}
+		forceinline constexpr HalfCycles(IntType l) noexcept : WrappedInt<HalfCycles>(l) {}
 		forceinline constexpr HalfCycles() noexcept : WrappedInt<HalfCycles>() {}
 
-		forceinline constexpr HalfCycles(const Cycles &cycles) noexcept : WrappedInt<HalfCycles>(cycles.as_int() * 2) {}
-		forceinline constexpr HalfCycles(const HalfCycles &half_cycles) noexcept : WrappedInt<HalfCycles>(half_cycles.length_) {}
+		forceinline constexpr HalfCycles(const Cycles &cycles) noexcept : WrappedInt<HalfCycles>(cycles.as_integral() * 2) {}
 
 		/// @returns The number of whole cycles completely covered by this span of half cycles.
 		forceinline constexpr Cycles cycles() const {
@@ -215,6 +225,16 @@ class HalfCycles: public WrappedInt<HalfCycles> {
 			result.length_ = length_;
 			length_ = 0;
 		}
+
+		void fill(Cycles &result, const HalfCycles &divisor) {
+			result = Cycles(length_ / (divisor.length_ << 1));
+			length_ %= (divisor.length_ << 1);
+		}
+
+		void fill(HalfCycles &result, const HalfCycles &divisor) {
+			result.length_ = length_ / divisor.length_;
+			length_ %= divisor.length_;
+		}
 };
 
 // Create a specialisation of WrappedInt::flush for converting HalfCycles to Cycles

ClockReceiver/ClockingHintSource.hpp

@@ -67,7 +67,7 @@ class Source {
 		}
 
 		/// @returns the current preferred clocking strategy.
-		virtual Preference preferred_clocking() = 0;
+		virtual Preference preferred_clocking() const = 0;
 
 	private:
 		Observer *observer_ = nullptr;

ClockReceiver/DeferredQueue.hpp

@@ -13,62 +13,68 @@
 #include <vector>
 
 /*!
-	A DeferredQueue maintains a list of ordered actions and the times at which
-	they should happen, and divides a total execution period up into the portions
-	that occur between those actions, triggering each action when it is reached.
+	Provides the logic to insert into and traverse a list of future scheduled items.
 */
 template <typename TimeUnit> class DeferredQueue {
 	public:
-		/// Constructs a DeferredQueue that will call target(period) in between deferred actions.
-		DeferredQueue(std::function<void(TimeUnit)> &&target) : target_(std::move(target)) {}
-
 		/*!
 			Schedules @c action to occur in @c delay units of time.
-
-			Actions must be scheduled in the order they will occur. It is undefined behaviour
-			to schedule them out of order.
 		*/
 		void defer(TimeUnit delay, const std::function<void(void)> &action) {
-			pending_actions_.emplace_back(delay, action);
-		}
-
-		/*!
-			Runs for @c length units of time.
-
-			The constructor-supplied target will be called with one or more periods that add up to @c length;
-			any scheduled actions will be called between periods.
-		*/
-		void run_for(TimeUnit length) {
-			// If there are no pending actions, just run for the entire length.
-			// This should be the normal branch.
-			if(pending_actions_.empty()) {
-				target_(length);
+			// Apply immediately if there's no delay (or a negative delay).
+			if(delay <= TimeUnit(0)) {
+				action();
 				return;
 			}
 
-			// Divide the time to run according to the pending actions.
-			while(length > TimeUnit(0)) {
-				TimeUnit next_period = pending_actions_.empty() ? length : std::min(length, pending_actions_[0].delay);
-				target_(next_period);
-				length -= next_period;
+			if(!pending_actions_.empty()) {
+				// Otherwise enqueue, having subtracted the delay for any preceding events,
+				// and subtracting from the subsequent, if any.
+				auto insertion_point = pending_actions_.begin();
+				while(insertion_point != pending_actions_.end() && insertion_point->delay < delay) {
+					delay -= insertion_point->delay;
+					++insertion_point;
+				}
+				if(insertion_point != pending_actions_.end()) {
+					insertion_point->delay -= delay;
+				}
 
-				off_t performances = 0;
-				for(auto &action: pending_actions_) {
-					action.delay -= next_period;
-					if(!action.delay) {
-						action.action();
-						++performances;
-					}
-				}
-				if(performances) {
-					pending_actions_.erase(pending_actions_.begin(), pending_actions_.begin() + performances);
+				pending_actions_.emplace(insertion_point, delay, action);
+			} else {
+				pending_actions_.emplace_back(delay, action);
+			}
+		}
+
+		/*!
+			@returns The amount of time until the next enqueued action will occur,
+				or TimeUnit(-1) if the queue is empty.
+		*/
+		TimeUnit time_until_next_action() const {
+			if(pending_actions_.empty()) return TimeUnit(-1);
+			return pending_actions_.front().delay;
+		}
+
+		/*!
+			Advances the queue the specified amount of time, performing any actions it reaches.
+		*/
+		void advance(TimeUnit time) {
+			auto erase_iterator = pending_actions_.begin();
+			while(erase_iterator != pending_actions_.end()) {
+				erase_iterator->delay -= time;
+				if(erase_iterator->delay <= TimeUnit(0)) {
+					time = -erase_iterator->delay;
+					erase_iterator->action();
+					++erase_iterator;
+				} else {
+					break;
 				}
 			}
+			if(erase_iterator != pending_actions_.begin()) {
+				pending_actions_.erase(pending_actions_.begin(), erase_iterator);
+			}
 		}
 
 	private:
-		std::function<void(TimeUnit)> target_;
-
 		// The list of deferred actions.
 		struct DeferredAction {
 			TimeUnit delay;
@@ -79,4 +85,40 @@ template <typename TimeUnit> class DeferredQueue {
 		std::vector<DeferredAction> pending_actions_;
 };
 
+/*!
+	A DeferredQueue maintains a list of ordered actions and the times at which
+	they should happen, and divides a total execution period up into the portions
+	that occur between those actions, triggering each action when it is reached.
+
+	This list is efficient only for short queues.
+*/
+template <typename TimeUnit> class DeferredQueuePerformer: public DeferredQueue<TimeUnit> {
+	public:
+		/// Constructs a DeferredQueue that will call target(period) in between deferred actions.
+		constexpr DeferredQueuePerformer(std::function<void(TimeUnit)> &&target) : target_(std::move(target)) {}
+
+		/*!
+			Runs for @c length units of time.
+
+			The constructor-supplied target will be called with one or more periods that add up to @c length;
+			any scheduled actions will be called between periods.
+		*/
+		void run_for(TimeUnit length) {
+			auto time_to_next = DeferredQueue<TimeUnit>::time_until_next_action();
+			while(time_to_next != TimeUnit(-1) && time_to_next <= length) {
+				target_(time_to_next);
+				length -= time_to_next;
+				DeferredQueue<TimeUnit>::advance(time_to_next);
+			}
+
+			DeferredQueue<TimeUnit>::advance(length);
+			target_(length);
+
+			// TODO: optimise this to avoid the multiple std::vector deletes. Find a neat way to expose that solution, maybe?
+		}
+
+	private:
+		std::function<void(TimeUnit)> target_;
+};
+
 #endif /* DeferredQueue_h */

ClockReceiver/ForceInline.hpp

@@ -9,9 +9,9 @@
 #ifndef ForceInline_hpp
 #define ForceInline_hpp
 
-#ifdef DEBUG
+#ifndef NDEBUG
 
-#define forceinline
+#define forceinline inline
 
 #else
 

ClockReceiver/JustInTime.hpp

@@ -10,6 +10,7 @@
 #define JustInTime_h
 
 #include "../Concurrency/AsyncTaskQueue.hpp"
+#include "ForceInline.hpp"
 
 /*!
 	A JustInTimeActor holds (i) an embedded object with a run_for method; and (ii) an amount
@@ -21,32 +22,52 @@
 	Machines that accumulate HalfCycle time but supply to a Cycle-counted device may supply a
 	separate @c TargetTimeScale at template declaration.
 */
-template <class T, class LocalTimeScale, class TargetTimeScale = LocalTimeScale> class JustInTimeActor {
+template <class T, int multiplier = 1, int divider = 1, class LocalTimeScale = HalfCycles, class TargetTimeScale = LocalTimeScale> class JustInTimeActor {
 	public:
 		/// Constructs a new JustInTimeActor using the same construction arguments as the included object.
 		template<typename... Args> JustInTimeActor(Args&&... args) : object_(std::forward<Args>(args)...) {}
 
 		/// Adds time to the actor.
-		inline void operator += (const LocalTimeScale &rhs) {
-			time_since_update_ += rhs;
+		forceinline void operator += (const LocalTimeScale &rhs) {
+			if constexpr (multiplier != 1) {
+				time_since_update_ += rhs * multiplier;
+			} else {
+				time_since_update_ += rhs;
+			}
 			is_flushed_ = false;
 		}
 
 		/// Flushes all accumulated time and returns a pointer to the included object.
-		inline T *operator->() {
+		forceinline T *operator->() {
 			flush();
 			return &object_;
 		}
 
+		/// Acts exactly as per the standard ->, but preserves constness.
+		forceinline const T *operator->() const {
+			auto non_const_this = const_cast<JustInTimeActor<T, multiplier, divider, LocalTimeScale, TargetTimeScale> *>(this);
+			non_const_this->flush();
+			return &object_;
+		}
+
 		/// Returns a pointer to the included object without flushing time.
-		inline T *last_valid() {
+		forceinline T *last_valid() {
 			return &object_;
 		}
 
 		/// Flushes all accumulated time.
-		inline void flush() {
-			if(!is_flushed_) object_.run_for(time_since_update_.template flush<TargetTimeScale>());
-			is_flushed_ = true;
+		forceinline void flush() {
+			if(!is_flushed_) {
+				is_flushed_ = true;
+				if constexpr (divider == 1) {
+					const auto duration = time_since_update_.template flush<TargetTimeScale>();
+					object_.run_for(duration);
+				} else {
+					const auto duration = time_since_update_.template divide<TargetTimeScale>(LocalTimeScale(divider));
+					if(duration > TargetTimeScale(0))
+						object_.run_for(duration);
+				}
+			}
 		}
 
 	private:
@@ -55,12 +76,54 @@ template <class T, class LocalTimeScale, class TargetTimeScale = LocalTimeScale>
 		bool is_flushed_ = true;
 };
 
+/*!
+	A RealTimeActor presents the same interface as a JustInTimeActor but doesn't defer work.
+	Time added will be performed immediately.
+
+	Its primary purpose is to allow consumers to remain flexible in their scheduling.
+*/
+template <class T, int multiplier = 1, int divider = 1, class LocalTimeScale = HalfCycles, class TargetTimeScale = LocalTimeScale> class RealTimeActor {
+	public:
+		template<typename... Args> RealTimeActor(Args&&... args) : object_(std::forward<Args>(args)...) {}
+
+		forceinline void operator += (const LocalTimeScale &rhs) {
+			if constexpr (multiplier == 1 && divider == 1) {
+				object_.run_for(TargetTimeScale(rhs));
+				return;
+			}
+
+			if constexpr (multiplier == 1) {
+				accumulated_time_ += rhs;
+			} else {
+				accumulated_time_ += rhs * multiplier;
+			}
+
+			if constexpr (divider == 1) {
+				const auto duration = accumulated_time_.template flush<TargetTimeScale>();
+				object_.run_for(duration);
+			} else {
+				const auto duration = accumulated_time_.template divide<TargetTimeScale>(LocalTimeScale(divider));
+				if(duration > TargetTimeScale(0))
+					object_.run_for(duration);
+			}
+		}
+
+		forceinline T *operator->()				{	return &object_;	}
+		forceinline const T *operator->() const	{	return &object_;	}
+		forceinline T *last_valid() 			{	return &object_;	}
+		forceinline void flush()				{}
+
+	private:
+		T object_;
+		LocalTimeScale accumulated_time_;
+};
+
 /*!
 	A AsyncJustInTimeActor acts like a JustInTimeActor but additionally contains an AsyncTaskQueue.
 	Any time the amount of accumulated time crosses a threshold provided at construction time,
 	the object will be updated on the AsyncTaskQueue.
 */
-template <class T, class LocalTimeScale, class TargetTimeScale = LocalTimeScale> class AsyncJustInTimeActor {
+template <class T, class LocalTimeScale = HalfCycles, class TargetTimeScale = LocalTimeScale> class AsyncJustInTimeActor {
 	public:
 		/// Constructs a new AsyncJustInTimeActor using the same construction arguments as the included object.
 		template<typename... Args> AsyncJustInTimeActor(TargetTimeScale threshold, Args&&... args) :

ClockReceiver/ScanSynchroniser.hpp

@@ -0,0 +1,88 @@
+//
+//  ScanSynchroniser.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 09/02/2020.
+//  Copyright © 2020 Thomas Harte. All rights reserved.
+//
+
+#ifndef ScanSynchroniser_h
+#define ScanSynchroniser_h
+
+#include "../Outputs/ScanTarget.hpp"
+
+#include <cmath>
+
+namespace Time {
+
+/*!
+	Where an emulated machine is sufficiently close to a host machine's frame rate that a small nudge in
+	its speed multiplier will bring it into frame synchronisation, the ScanSynchroniser provides a sequence of
+	speed multipliers designed both to adjust the machine to the proper speed and, in a reasonable amount
+	of time, to bring it into phase.
+*/
+class ScanSynchroniser {
+	public:
+		/*!
+			@returns @c true if the emulated machine can be synchronised with the host frame output based on its
+				current @c [scan]status and the host machine's @c frame_duration; @c false otherwise.
+		*/
+		bool can_synchronise(const Outputs::Display::ScanStatus &scan_status, double frame_duration) {
+			ratio_ = 1.0;
+			if(scan_status.field_duration_gradient < 0.00001) {
+				// Check out the machine's current frame time.
+				// If it's within 3% of a non-zero integer multiple of the
+				// display rate, mark this time window to be split over the sync.
+				ratio_ = (frame_duration * base_multiplier_) / scan_status.field_duration;
+				const double integer_ratio = round(ratio_);
+				if(integer_ratio > 0.0) {
+					ratio_ /= integer_ratio;
+					return ratio_ <= maximum_rate_adjustment && ratio_ >= 1.0 / maximum_rate_adjustment;
+				}
+			}
+			return false;
+		}
+
+		/*!
+			@returns The appropriate speed multiplier for the next frame based on the inputs previously supplied to @c can_synchronise.
+				Results are undefined if @c can_synchroise returned @c false.
+		*/
+		double next_speed_multiplier(const Outputs::Display::ScanStatus &scan_status) {
+			// The host versus emulated ratio is calculated based on the current perceived frame duration of the machine.
+			// Either that number is exactly correct or it's already the result of some sort of low-pass filter. So there's
+			// no benefit to second guessing it here — just take it to be correct.
+			//
+			// ... with one slight caveat, which is that it is desireable to adjust phase here, to align vertical sync points.
+			// So the set speed multiplier may be adjusted slightly to aim for that.
+			double speed_multiplier = 1.0 / (ratio_ / base_multiplier_);
+			if(scan_status.current_position > 0.0) {
+				if(scan_status.current_position < 0.5) speed_multiplier /= phase_adjustment_ratio;
+				else speed_multiplier *= phase_adjustment_ratio;
+			}
+			speed_multiplier_ = (speed_multiplier_ * 0.95) + (speed_multiplier * 0.05);
+			return speed_multiplier_ * base_multiplier_;
+		}
+
+		void set_base_speed_multiplier(double multiplier) {
+			base_multiplier_ = multiplier;
+		}
+
+		double get_base_speed_multiplier() {
+			return base_multiplier_;
+		}
+
+	private:
+		static constexpr double maximum_rate_adjustment = 1.03;
+		static constexpr double phase_adjustment_ratio = 1.005;
+
+		// Managed local state.
+		double speed_multiplier_ = 1.0;
+		double base_multiplier_ = 1.0;
+
+		// Temporary storage to bridge the can_synchronise -> next_speed_multiplier gap.
+		double ratio_ = 1.0;
+};
+
+}
+
+#endif /* ScanSynchroniser_h */

ClockReceiver/TimeTypes.hpp

@@ -9,9 +9,16 @@
 #ifndef TimeTypes_h
 #define TimeTypes_h
 
+#include <chrono>
+
 namespace Time {
 
 typedef double Seconds;
+typedef int64_t Nanos;
+
+inline Nanos nanos_now() {
+	return std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::high_resolution_clock::now().time_since_epoch()).count();
+}
 
 }
 

ClockReceiver/VSyncPredictor.hpp

@@ -0,0 +1,155 @@
+//
+//  VSyncPredictor.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 14/06/2020.
+//  Copyright © 2020 Thomas Harte. All rights reserved.
+//
+
+#ifndef VSyncPredictor_hpp
+#define VSyncPredictor_hpp
+
+#include "TimeTypes.hpp"
+#include <cassert>
+#include <cmath>
+#include <cstdio>
+
+namespace Time {
+
+/*!
+	For platforms that provide no avenue into vsync tracking other than block-until-sync,
+	this class tracks: (i) how long frame draw takes; (ii) the apparent frame period; and
+	(iii) optionally, timer jitter; in order to suggest when you should next start drawing.
+*/
+class VSyncPredictor {
+	public:
+		/*!
+			Announces to the predictor that the work of producing an output frame has begun.
+		*/
+		void begin_redraw() {
+			redraw_begin_time_ = nanos_now();
+		}
+
+		/*!
+			Announces to the predictor that the work of producing an output frame has ended;
+			the predictor will use the amount of time between each begin/end pair to modify
+			its expectations as to how long it takes to draw a frame.
+		*/
+		void end_redraw() {
+			redraw_period_.post(nanos_now() - redraw_begin_time_);
+		}
+
+		/*!
+			Informs the predictor that a block-on-vsync has just ended, i.e. that the moment this
+			machine calls retrace is now. The predictor uses these notifications to estimate output
+			frame rate.
+		*/
+		void announce_vsync() {
+			const auto now = nanos_now();
+
+			if(last_vsync_) {
+				last_vsync_ += frame_duration_;
+				vsync_jitter_.post(last_vsync_ - now);
+				last_vsync_ = (last_vsync_ + now) >> 1;
+			} else {
+				last_vsync_ = now;
+			}
+		}
+
+		/*!
+			Sets the frame rate for the target display.
+		*/
+		void set_frame_rate(float rate) {
+			frame_duration_ = Nanos(1'000'000'000.0f / rate);
+		}
+
+		/*!
+			@returns The time this class currently believes a whole frame occupies.
+		*/
+		Time::Nanos frame_duration() {
+			return frame_duration_;
+		}
+
+		/*!
+			Adds a record of how much jitter was experienced in scheduling; these values will be
+			factored into the @c suggested_draw_time if supplied.
+
+			A positive number means the timer occurred late. A negative number means it occurred early.
+		*/
+		void add_timer_jitter(Time::Nanos jitter) {
+			timer_jitter_.post(jitter);
+		}
+
+		/*!
+			Announces to the vsync predictor that output is now paused. This ends frame period
+			calculations until the next announce_vsync() restarts frame-length counting.
+		*/
+		void pause() {
+			last_vsync_ = 0;
+		}
+
+		/*!
+			@return The time at which redrawing should begin, given the predicted frame period, how
+			long it appears to take to draw a frame and how much jitter there is in scheduling
+			(if those figures are being supplied).
+		*/
+		Nanos suggested_draw_time() {
+			const auto mean = redraw_period_.mean() + timer_jitter_.mean() + vsync_jitter_.mean();
+			const auto variance = redraw_period_.variance() + timer_jitter_.variance() + vsync_jitter_.variance();
+
+			// Permit three standard deviations from the mean, to cover 99.9% of cases.
+			const auto period = mean + Nanos(3.0f * sqrt(float(variance)));
+
+			return last_vsync_ + frame_duration_ - period;
+		}
+
+	private:
+		class VarianceCollector {
+			public:
+				VarianceCollector(Time::Nanos default_value) {
+					sum_ = default_value * 128;
+					for(int c = 0; c < 128; ++c) {
+						history_[c] = default_value;
+					}
+				}
+
+				void post(Time::Nanos value) {
+					sum_ -= history_[write_pointer_];
+					sum_ += value;
+					history_[write_pointer_] = value;
+					write_pointer_ = (write_pointer_ + 1) & 127;
+				}
+
+				Time::Nanos mean() {
+					return sum_ / 128;
+				}
+
+				Time::Nanos variance() {
+					// I haven't yet come up with a better solution that calculating this
+					// in whole every time, given the way that the mean mutates.
+					Time::Nanos variance = 0;
+					for(int c = 0; c < 128; ++c) {
+						const auto difference = ((history_[c] * 128) - sum_) / 128;
+						variance += (difference * difference);
+					}
+					return variance / 128;
+				}
+
+			private:
+				Time::Nanos sum_;
+				Time::Nanos history_[128];
+				size_t write_pointer_ = 0;
+		};
+
+		Nanos redraw_begin_time_ = 0;
+		Nanos last_vsync_ = 0;
+		Nanos frame_duration_ = 1'000'000'000 / 60;
+
+		VarianceCollector vsync_jitter_{0};
+		VarianceCollector redraw_period_{1'000'000'000 / 60};	// A less convincing first guess.
+		VarianceCollector timer_jitter_{0};						// Seed at 0 in case this feature isn't used by the owner.
+};
+
+}
+
+#endif /* VSyncPredictor_hpp */

Components/1770/1770.cpp

@@ -9,6 +9,8 @@
 #include "1770.hpp"
 
 #include "../../Storage/Disk/Encodings/MFM/Constants.hpp"
+
+#define LOG_PREFIX "[WD FDC] "
 #include "../../Outputs/Log.hpp"
 
 using namespace WD;
@@ -16,19 +18,19 @@ using namespace WD;
 WD1770::WD1770(Personality p) :
 		Storage::Disk::MFMController(8000000),
 		personality_(p),
-		interesting_event_mask_(static_cast<int>(Event1770::Command)) {
+		interesting_event_mask_(int(Event1770::Command)) {
 	set_is_double_density(false);
-	posit_event(static_cast<int>(Event1770::Command));
+	posit_event(int(Event1770::Command));
 }
 
-void WD1770::set_register(int address, uint8_t value) {
+void WD1770::write(int address, uint8_t value) {
 	switch(address&3) {
 		case 0: {
 			if((value&0xf0) == 0xd0) {
 				if(value == 0xd0) {
 					// Force interrupt **immediately**.
 					LOG("Force interrupt immediately");
-					posit_event(static_cast<int>(Event1770::ForceInterrupt));
+					posit_event(int(Event1770::ForceInterrupt));
 				} else {
 					ERROR("!!!TODO: force interrupt!!!");
 					update_status([] (Status &status) {
@@ -37,7 +39,7 @@ void WD1770::set_register(int address, uint8_t value) {
 				}
 			} else {
 				command_ = value;
-				posit_event(static_cast<int>(Event1770::Command));
+				posit_event(int(Event1770::Command));
 			}
 		}
 		break;
@@ -52,27 +54,35 @@ void WD1770::set_register(int address, uint8_t value) {
 	}
 }
 
-uint8_t WD1770::get_register(int address) {
+uint8_t WD1770::read(int address) {
 	switch(address&3) {
 		default: {
 			update_status([] (Status &status) {
 				status.interrupt_request = false;
 			});
 			uint8_t status =
-					(status_.write_protect ? Flag::WriteProtect : 0) |
-					(status_.crc_error ? Flag::CRCError : 0) |
-					(status_.busy ? Flag::Busy : 0);
+				(status_.crc_error ? Flag::CRCError : 0) |
+				(status_.busy ? Flag::Busy : 0);
+
+			// Per Jean Louis-Guérin's documentation:
+			//
+			//	* 	the write-protect bit is locked into place by a type 2 or type 3 command, but is
+			//		read live after a type 1.
+			//	*	the track 0 bit is captured during a type 1 instruction and lost upon any other type,
+			//		it is not live sampled.
 			switch(status_.type) {
 				case Status::One:
 					status |=
-						(get_drive().get_is_track_zero() ? Flag::TrackZero : 0) |
-						(status_.seek_error ? Flag::SeekError : 0);
-						// TODO: index hole
+						(status_.track_zero ? Flag::TrackZero : 0) |
+						(status_.seek_error ? Flag::SeekError : 0) |
+						(get_drive().get_is_read_only() ? Flag::WriteProtect : 0) |
+						(get_drive().get_index_pulse() ? Flag::Index : 0);
 				break;
 
 				case Status::Two:
 				case Status::Three:
 					status |=
+						(status_.write_protect ? Flag::WriteProtect : 0) |
 						(status_.record_type ? Flag::RecordType : 0) |
 						(status_.lost_data ? Flag::LostData : 0) |
 						(status_.data_request ? Flag::DataRequest : 0) |
@@ -89,10 +99,15 @@ uint8_t WD1770::get_register(int address) {
 				if(status_.type == Status::One)
 					status |= (status_.spin_up ? Flag::SpinUp : 0);
 			}
+//			LOG("Returned status " << PADHEX(2) << int(status) << " of type " << 1+int(status_.type));
 			return status;
 		}
-		case 1:		return track_;
-		case 2:		return sector_;
+		case 1:
+			LOG("Returned track " << int(track_));
+			return track_;
+		case 2:
+			LOG("Returned sector " << int(sector_));
+			return sector_;
 		case 3:
 			update_status([] (Status &status) {
 				status.data_request = false;
@@ -105,28 +120,30 @@ void WD1770::run_for(const Cycles cycles) {
 	Storage::Disk::Controller::run_for(cycles);
 
 	if(delay_time_) {
-		unsigned int number_of_cycles = static_cast<unsigned int>(cycles.as_int());
+		const auto number_of_cycles = cycles.as_integral();
 		if(delay_time_ <= number_of_cycles) {
 			delay_time_ = 0;
-			posit_event(static_cast<int>(Event1770::Timer));
+			posit_event(int(Event1770::Timer));
 		} else {
 			delay_time_ -= number_of_cycles;
 		}
 	}
 }
 
-#define WAIT_FOR_EVENT(mask)	resume_point_ = __LINE__; interesting_event_mask_ = static_cast<int>(mask); return; case __LINE__:
+#define WAIT_FOR_EVENT(mask)	resume_point_ = __LINE__; interesting_event_mask_ = int(mask); return; case __LINE__:
 #define WAIT_FOR_TIME(ms)		resume_point_ = __LINE__; delay_time_ = ms * 8000; WAIT_FOR_EVENT(Event1770::Timer);
-#define WAIT_FOR_BYTES(count)	resume_point_ = __LINE__; distance_into_section_ = 0; WAIT_FOR_EVENT(Event::Token); if(get_latest_token().type == Token::Byte) distance_into_section_++; if(distance_into_section_ < count) { interesting_event_mask_ = static_cast<int>(Event::Token); return; }
+#define WAIT_FOR_BYTES(count)	resume_point_ = __LINE__; distance_into_section_ = 0; WAIT_FOR_EVENT(Event::Token); if(get_latest_token().type == Token::Byte) distance_into_section_++; if(distance_into_section_ < count) { interesting_event_mask_ = int(Event::Token); return; }
 #define BEGIN_SECTION()	switch(resume_point_) { default:
 #define END_SECTION()	(void)0; }
 
 #define READ_ID()	\
-		if(new_event_type == static_cast<int>(Event::Token)) {	\
-			if(!distance_into_section_ && get_latest_token().type == Token::ID) {set_data_mode(DataMode::Reading); distance_into_section_++; }	\
-			else if(distance_into_section_ && distance_into_section_ < 7 && get_latest_token().type == Token::Byte) {	\
+		if(new_event_type == int(Event::Token)) {	\
+			if(!distance_into_section_ && get_latest_token().type == Token::ID) {\
+				set_data_mode(DataMode::Reading);	\
+				++distance_into_section_;	\
+			} else if(distance_into_section_ && distance_into_section_ < 7 && get_latest_token().type == Token::Byte) {	\
 				header_[distance_into_section_ - 1] = get_latest_token().byte_value;	\
-				distance_into_section_++;	\
+				++distance_into_section_;	\
 			}	\
 		}
 
@@ -159,10 +176,10 @@ void WD1770::run_for(const Cycles cycles) {
 // +--------+----------+-------------------------+
 
 void WD1770::posit_event(int new_event_type) {
-	if(new_event_type == static_cast<int>(Event::IndexHole)) {
+	if(new_event_type == int(Event::IndexHole)) {
 		index_hole_count_++;
 		if(index_hole_count_target_ == index_hole_count_) {
-			posit_event(static_cast<int>(Event1770::IndexHoleTarget));
+			posit_event(int(Event1770::IndexHoleTarget));
 			index_hole_count_target_ = -1;
 		}
 
@@ -177,15 +194,16 @@ void WD1770::posit_event(int new_event_type) {
 		}
 	}
 
-	if(new_event_type == static_cast<int>(Event1770::ForceInterrupt)) {
+	if(new_event_type == int(Event1770::ForceInterrupt)) {
 		interesting_event_mask_ = 0;
 		resume_point_ = 0;
 		update_status([] (Status &status) {
 			status.type = Status::One;
 			status.data_request = false;
+			status.spin_up = false;
 		});
 	} else {
-		if(!(interesting_event_mask_ & static_cast<int>(new_event_type))) return;
+		if(!(interesting_event_mask_ & int(new_event_type))) return;
 		interesting_event_mask_ &= ~new_event_type;
 	}
 
@@ -208,6 +226,7 @@ void WD1770::posit_event(int new_event_type) {
 		update_status([] (Status &status) {
 			status.busy = true;
 			status.interrupt_request = false;
+			status.track_zero = false;	// Always reset by a non-type 1; so reset regardless and set properly later.
 		});
 
 		LOG("Starting " << PADHEX(2) << int(command_));
@@ -240,6 +259,7 @@ void WD1770::posit_event(int new_event_type) {
 			status.data_request = false;
 		});
 
+		LOG("Step/Seek/Restore with track " << int(track_) << " data " << int(data_));
 		if(!has_motor_on_line() && !has_head_load_line()) goto test_type1_type;
 
 		if(has_motor_on_line()) goto begin_type1_spin_up;
@@ -272,19 +292,19 @@ void WD1770::posit_event(int new_event_type) {
 		}
 
 	perform_seek_or_restore_command:
-		if(track_ == data_) goto verify;
+		if(track_ == data_) goto verify_seek;
 		step_direction_ = (data_ > track_);
 
 	adjust_track:
-		if(step_direction_) track_++; else track_--;
+		if(step_direction_) ++track_; else --track_;
 
 	perform_step:
 		if(!step_direction_ && get_drive().get_is_track_zero()) {
 			track_ = 0;
-			goto verify;
+			goto verify_seek;
 		}
 		get_drive().step(Storage::Disk::HeadPosition(step_direction_ ? 1 : -1));
-		unsigned int time_to_wait;
+		Cycles::IntType time_to_wait;
 		switch(command_ & 3) {
 			default:
 			case 0: time_to_wait = 6;	break;
@@ -293,14 +313,17 @@ void WD1770::posit_event(int new_event_type) {
 			case 3: time_to_wait = (personality_ == P1772) ? 3 : 30;	break;
 		}
 		WAIT_FOR_TIME(time_to_wait);
-		if(command_ >> 5) goto verify;
+		if(command_ >> 5) goto verify_seek;
 		goto perform_seek_or_restore_command;
 
 	perform_step_command:
 		if(command_ & 0x10) goto adjust_track;
 		goto perform_step;
 
-	verify:
+	verify_seek:
+		update_status([this] (Status &status) {
+			status.track_zero = get_drive().get_is_track_zero();
+		});
 		if(!(command_ & 0x04)) {
 			goto wait_for_command;
 		}
@@ -309,17 +332,20 @@ void WD1770::posit_event(int new_event_type) {
 		distance_into_section_ = 0;
 
 	verify_read_data:
-		WAIT_FOR_EVENT(static_cast<int>(Event::IndexHole) | static_cast<int>(Event::Token));
+		WAIT_FOR_EVENT(int(Event::IndexHole) | int(Event::Token));
 		READ_ID();
 
 		if(index_hole_count_ == 6) {
+			LOG("Nothing found to verify");
 			update_status([] (Status &status) {
 				status.seek_error = true;
 			});
 			goto wait_for_command;
 		}
 		if(distance_into_section_ == 7) {
+			distance_into_section_ = 0;
 			set_data_mode(DataMode::Scanning);
+
 			if(get_crc_generator().get_value()) {
 				update_status([] (Status &status) {
 					status.crc_error = true;
@@ -334,8 +360,6 @@ void WD1770::posit_event(int new_event_type) {
 				});
 				goto wait_for_command;
 			}
-
-			distance_into_section_ = 0;
 		}
 		goto verify_read_data;
 
@@ -392,8 +416,11 @@ void WD1770::posit_event(int new_event_type) {
 			goto wait_for_command;
 		}
 
+		distance_into_section_ = 0;
+		set_data_mode(DataMode::Scanning);
+
 	type2_get_header:
-		WAIT_FOR_EVENT(static_cast<int>(Event::IndexHole) | static_cast<int>(Event::Token));
+		WAIT_FOR_EVENT(int(Event::IndexHole) | int(Event::Token));
 		READ_ID();
 
 		if(index_hole_count_ == 5) {
@@ -404,8 +431,10 @@ void WD1770::posit_event(int new_event_type) {
 			goto wait_for_command;
 		}
 		if(distance_into_section_ == 7) {
-			LOG("Considering " << std::dec << int(header_[0]) << "/" << int(header_[2]));
+			distance_into_section_ = 0;
 			set_data_mode(DataMode::Scanning);
+
+			LOG("Considering " << std::dec << int(header_[0]) << "/" << int(header_[2]));
 			if(		header_[0] == track_ && header_[2] == sector_ &&
 					(has_motor_on_line() || !(command_&0x02) || ((command_&0x08) >> 3) == header_[1])) {
 				LOG("Found " << std::dec << int(header_[0]) << "/" << int(header_[2]));
@@ -422,7 +451,6 @@ void WD1770::posit_event(int new_event_type) {
 				});
 				goto type2_read_or_write_data;
 			}
-			distance_into_section_ = 0;
 		}
 		goto type2_get_header;
 
@@ -453,7 +481,7 @@ void WD1770::posit_event(int new_event_type) {
 			status.data_request = true;
 		});
 		distance_into_section_++;
-		if(distance_into_section_ == 128 << header_[3]) {
+		if(distance_into_section_ == 128 << (header_[3]&3)) {
 			distance_into_section_ = 0;
 			goto type2_check_crc;
 		}
@@ -465,19 +493,24 @@ void WD1770::posit_event(int new_event_type) {
 		header_[distance_into_section_] = get_latest_token().byte_value;
 		distance_into_section_++;
 		if(distance_into_section_ == 2) {
+			distance_into_section_ = 0;
+			set_data_mode(DataMode::Scanning);
+
 			if(get_crc_generator().get_value()) {
 				LOG("CRC error; terminating");
-				update_status([this] (Status &status) {
+				update_status([] (Status &status) {
 					status.crc_error = true;
 				});
 				goto wait_for_command;
 			}
 
+			LOG("Finished reading sector " << std::dec << int(sector_));
+
 			if(command_ & 0x10) {
 				sector_++;
+				LOG("Advancing to search for sector " << std::dec << int(sector_));
 				goto test_type2_write_protection;
 			}
-			LOG("Finished reading sector " << std::dec << int(sector_));
 			goto wait_for_command;
 		}
 		goto type2_check_crc;
@@ -531,7 +564,7 @@ void WD1770::posit_event(int new_event_type) {
 		*/
 		write_byte(data_);
 		distance_into_section_++;
-		if(distance_into_section_ == 128 << header_[3]) {
+		if(distance_into_section_ == 128 << (header_[3]&3)) {
 			goto type2_write_crc;
 		}
 
@@ -610,8 +643,8 @@ void WD1770::posit_event(int new_event_type) {
 		distance_into_section_ = 0;
 
 	read_address_get_header:
-		WAIT_FOR_EVENT(static_cast<int>(Event::IndexHole) | static_cast<int>(Event::Token));
-		if(new_event_type == static_cast<int>(Event::Token)) {
+		WAIT_FOR_EVENT(int(Event::IndexHole) | int(Event::Token));
+		if(new_event_type == int(Event::Token)) {
 			if(!distance_into_section_ && get_latest_token().type == Token::ID) {set_data_mode(DataMode::Reading); distance_into_section_++; }
 			else if(distance_into_section_ && distance_into_section_ < 7 && get_latest_token().type == Token::Byte) {
 				if(status_.data_request) {
@@ -625,9 +658,11 @@ void WD1770::posit_event(int new_event_type) {
 				update_status([] (Status &status) {
 					status.data_request = true;
 				});
-				distance_into_section_++;
+				++distance_into_section_;
 
 				if(distance_into_section_ == 7) {
+					distance_into_section_ = 0;
+
 					if(get_crc_generator().get_value()) {
 						update_status([] (Status &status) {
 							status.crc_error = true;
@@ -651,7 +686,7 @@ void WD1770::posit_event(int new_event_type) {
 		index_hole_count_ = 0;
 
 	read_track_read_byte:
-		WAIT_FOR_EVENT(static_cast<int>(Event::Token) | static_cast<int>(Event::IndexHole));
+		WAIT_FOR_EVENT(int(Event::Token) | int(Event::IndexHole));
 		if(index_hole_count_) {
 			goto wait_for_command;
 		}
@@ -718,7 +753,7 @@ void WD1770::posit_event(int new_event_type) {
 				case 0xfd: case 0xfe:
 					// clock is 0xc7 = 1010 0000 0010 1010 = 0xa022
 					write_raw_short(
-						static_cast<uint16_t>(
+						uint16_t(
 							0xa022 |
 							((data_ & 0x80) << 7) |
 							((data_ & 0x40) << 6) |
@@ -767,21 +802,33 @@ void WD1770::posit_event(int new_event_type) {
 }
 
 void WD1770::update_status(std::function<void(Status &)> updater) {
+	const Status old_status = status_;
+
 	if(delegate_) {
-		Status old_status = status_;
 		updater(status_);
-		bool did_change =
+		const bool did_change =
 			(status_.busy != old_status.busy) ||
-			(status_.data_request != old_status.data_request);
+			(status_.data_request != old_status.data_request) ||
+			(status_.interrupt_request != old_status.interrupt_request);
 		if(did_change) delegate_->wd1770_did_change_output(this);
-	}
-	else updater(status_);
+	} else updater(status_);
+
+	if(status_.busy != old_status.busy) update_clocking_observer();
 }
 
-void WD1770::set_head_load_request(bool head_load) {}
-void WD1770::set_motor_on(bool motor_on) {}
+void WD1770::set_head_load_request(bool) {}
+void WD1770::set_motor_on(bool) {}
 
 void WD1770::set_head_loaded(bool head_loaded) {
 	head_is_loaded_ = head_loaded;
-	if(head_loaded) posit_event(static_cast<int>(Event1770::HeadLoad));
+	if(head_loaded) posit_event(int(Event1770::HeadLoad));
+}
+
+bool WD1770::get_head_loaded() const {
+	return head_is_loaded_;
+}
+
+ClockingHint::Preference WD1770::preferred_clocking() const {
+	if(status_.busy) return ClockingHint::Preference::RealTime;
+	return Storage::Disk::MFMController::preferred_clocking();
 }

Components/1770/1770.hpp

@@ -31,57 +31,63 @@ class WD1770: public Storage::Disk::MFMController {
 			@param p The type of controller to emulate.
 		*/
 		WD1770(Personality p);
+		virtual ~WD1770() {}
 
 		/// Sets the value of the double-density input; when @c is_double_density is @c true, reads and writes double-density format data.
 		using Storage::Disk::MFMController::set_is_double_density;
 
 		/// Writes @c value to the register at @c address. Only the low two bits of the address are decoded.
-		void set_register(int address, uint8_t value);
+		void write(int address, uint8_t value);
 
 		/// Fetches the value of the register @c address. Only the low two bits of the address are decoded.
-		uint8_t get_register(int address);
+		uint8_t read(int address);
 
 		/// Runs the controller for @c number_of_cycles cycles.
 		void run_for(const Cycles cycles);
 
 		enum Flag: uint8_t {
-			NotReady		= 0x80,
+			NotReady		= 0x80,		// 0x80
 			MotorOn			= 0x80,
-			WriteProtect	= 0x40,
-			RecordType		= 0x20,
+			WriteProtect	= 0x40,		// 0x40
+			RecordType		= 0x20,		// 0x20
 			SpinUp			= 0x20,
 			HeadLoaded		= 0x20,
-			RecordNotFound	= 0x10,
+			RecordNotFound	= 0x10,		// 0x10
 			SeekError		= 0x10,
-			CRCError		= 0x08,
-			LostData		= 0x04,
+			CRCError		= 0x08,		// 0x08
+			LostData		= 0x04,		// 0x04
 			TrackZero		= 0x04,
-			DataRequest		= 0x02,
+			DataRequest		= 0x02,		// 0x02
 			Index			= 0x02,
-			Busy			= 0x01
+			Busy			= 0x01		// 0x01
 		};
 
 		/// @returns The current value of the IRQ line output.
-		inline bool get_interrupt_request_line()		{	return status_.interrupt_request;	}
+		inline bool get_interrupt_request_line() const	{	return status_.interrupt_request;	}
 
 		/// @returns The current value of the DRQ line output.
-		inline bool get_data_request_line()				{	return status_.data_request;		}
+		inline bool get_data_request_line() const		{	return status_.data_request;		}
 
 		class Delegate {
 			public:
 				virtual void wd1770_did_change_output(WD1770 *wd1770) = 0;
 		};
-		inline void set_delegate(Delegate *delegate)	{	delegate_ = delegate;			}
+		inline void set_delegate(Delegate *delegate)	{	delegate_ = delegate;				}
+
+		ClockingHint::Preference preferred_clocking() const final;
 
 	protected:
 		virtual void set_head_load_request(bool head_load);
 		virtual void set_motor_on(bool motor_on);
 		void set_head_loaded(bool head_loaded);
 
+		/// @returns The last value posted to @c set_head_loaded.
+		bool get_head_loaded() const;
+
 	private:
-		Personality personality_;
-		inline bool has_motor_on_line() { return (personality_ != P1793 ) && (personality_ != P1773); }
-		inline bool has_head_load_line() { return (personality_ == P1793 ); }
+		const Personality personality_;
+		bool has_motor_on_line() const { return (personality_ != P1793 ) && (personality_ != P1773); }
+		bool has_head_load_line() const { return (personality_ == P1793 ); }
 
 		struct Status {
 			bool write_protect = false;
@@ -94,6 +100,7 @@ class WD1770: public Storage::Disk::MFMController {
 			bool data_request = false;
 			bool interrupt_request = false;
 			bool busy = false;
+			bool track_zero = false;
 			enum {
 				One, Two, Three
 			} type = One;
@@ -121,7 +128,7 @@ class WD1770: public Storage::Disk::MFMController {
 		void posit_event(int type);
 		int interesting_event_mask_;
 		int resume_point_ = 0;
-		unsigned int delay_time_ = 0;
+		Cycles::IntType delay_time_ = 0;
 
 		// ID buffer
 		uint8_t header_[6];

Components/5380/ncr5380.cpp

@@ -0,0 +1,318 @@
+//
+//  ncr5380.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 10/08/2019.
+//  Copyright © 2019 Thomas Harte. All rights reserved.
+//
+
+#include "ncr5380.hpp"
+
+#include "../../Outputs/Log.hpp"
+
+using namespace NCR::NCR5380;
+using SCSI::Line;
+
+NCR5380::NCR5380(SCSI::Bus &bus, int clock_rate) :
+	bus_(bus),
+	clock_rate_(clock_rate) {
+	device_id_ = bus_.add_device();
+	bus_.add_observer(this);
+
+	// TODO: use clock rate and expected phase. This implementation currently
+	// provides only CPU-driven polling behaviour.
+	(void)clock_rate_;
+	(void)expected_phase_;
+}
+
+void NCR5380::write(int address, uint8_t value, bool) {
+	switch(address & 7) {
+		case 0:
+//			LOG("[SCSI 0] Set current SCSI bus state to " << PADHEX(2) << int(value));
+			data_bus_ = value;
+
+			if(dma_request_ && dma_operation_ == DMAOperation::Send) {
+//				printf("w %02x\n", value);
+				dma_acknowledge_ = true;
+				dma_request_ = false;
+				update_control_output();
+				bus_.set_device_output(device_id_, bus_output_);
+			}
+		break;
+
+		case 1: {
+//			LOG("[SCSI 1] Initiator command register set: " << PADHEX(2) << int(value));
+			initiator_command_ = value;
+
+			bus_output_ &= ~(Line::Reset | Line::Acknowledge | Line::Busy | Line::SelectTarget | Line::Attention);
+			if(value & 0x80) bus_output_ |= Line::Reset;
+			if(value & 0x08) bus_output_ |= Line::Busy;
+			if(value & 0x04) bus_output_ |= Line::SelectTarget;
+
+			/* bit 5 = differential enable if this were a 5381 */
+
+			test_mode_ = value & 0x40;
+			assert_data_bus_ = value & 0x01;
+			update_control_output();
+		} break;
+
+		case 2:
+//			LOG("[SCSI 2] Set mode: " << PADHEX(2) << int(value));
+			mode_ = value;
+
+			// bit 7: 1 = use block mode DMA mode (if DMA mode is also enabled)
+			// bit 6: 1 = be a SCSI target; 0 = be an initiator
+			// bit 5: 1 = check parity
+			// bit 4: 1 = generate an interrupt if parity checking is enabled and an error is found
+			// bit 3: 1 = generate an interrupt when an EOP is received from the DMA controller
+			// bit 2: 1 = generate an interrupt and reset low 6 bits of register 1 if an unexpected loss of Line::Busy occurs
+			// bit 1: 1 = use DMA mode
+			// bit 0: 1 = begin arbitration mode (device ID should be in register 0)
+			arbitration_in_progress_ = false;
+			switch(mode_ & 0x3) {
+				case 0x0:
+					bus_output_ &= ~SCSI::Line::Busy;
+					dma_request_ = false;
+					set_execution_state(ExecutionState::None);
+				break;
+
+				case 0x1:
+					arbitration_in_progress_ = true;
+					set_execution_state(ExecutionState::WaitingForBusy);
+					lost_arbitration_ = false;
+				break;
+
+				default:
+					assert_data_bus_ = false;
+					set_execution_state(ExecutionState::PerformingDMA);
+					bus_.update_observers();
+				break;
+			}
+			update_control_output();
+		break;
+
+		case 3: {
+//			LOG("[SCSI 3] Set target command: " << PADHEX(2) << int(value));
+			target_command_ = value;
+			update_control_output();
+		} break;
+
+		case 4:
+//			LOG("[SCSI 4] Set select enabled: " << PADHEX(2) << int(value));
+		break;
+
+		case 5:
+//			LOG("[SCSI 5] Start DMA send: " << PADHEX(2) << int(value));
+			dma_operation_ = DMAOperation::Send;
+		break;
+
+		case 6:
+//			LOG("[SCSI 6] Start DMA target receive: " << PADHEX(2) << int(value));
+			dma_operation_ = DMAOperation::TargetReceive;
+		break;
+
+		case 7:
+//			LOG("[SCSI 7] Start DMA initiator receive: " << PADHEX(2) << int(value));
+			dma_operation_ = DMAOperation::InitiatorReceive;
+		break;
+	}
+
+	// Data is output only if the data bus is asserted.
+	if(assert_data_bus_) {
+		bus_output_ = (bus_output_ & ~SCSI::Line::Data) | data_bus_;
+	} else {
+		bus_output_ &= ~SCSI::Line::Data;
+	}
+
+	// In test mode, still nothing is output. Otherwise throw out
+	// the current value of bus_output_.
+	if(test_mode_) {
+		bus_.set_device_output(device_id_, SCSI::DefaultBusState);
+	} else {
+		bus_.set_device_output(device_id_, bus_output_);
+	}
+}
+
+uint8_t NCR5380::read(int address, bool) {
+	switch(address & 7) {
+		case 0:
+//			LOG("[SCSI 0] Get current SCSI bus state: " << PADHEX(2) << (bus_.get_state() & 0xff));
+
+			if(dma_request_ && dma_operation_ == DMAOperation::InitiatorReceive) {
+				dma_acknowledge_ = true;
+				dma_request_ = false;
+				update_control_output();
+				bus_.set_device_output(device_id_, bus_output_);
+			}
+		return uint8_t(bus_.get_state());
+
+		case 1:
+//			LOG("[SCSI 1] Initiator command register get: " << (arbitration_in_progress_ ? 'p' : '-') <<  (lost_arbitration_ ? 'l' : '-'));
+		return
+			// Bits repeated as they were set.
+			(initiator_command_ & ~0x60) |
+
+			// Arbitration in progress.
+			(arbitration_in_progress_ ? 0x40 : 0x00) |
+
+			// Lost arbitration.
+			(lost_arbitration_ ? 0x20 : 0x00);
+
+		case 2:
+//			LOG("[SCSI 2] Get mode");
+		return mode_;
+
+		case 3:
+//			LOG("[SCSI 3] Get target command");
+		return target_command_;
+
+		case 4: {
+			const auto bus_state = bus_.get_state();
+			const uint8_t result =
+				((bus_state & Line::Reset)			? 0x80 : 0x00) |
+				((bus_state & Line::Busy)			? 0x40 : 0x00) |
+				((bus_state & Line::Request)		? 0x20 : 0x00) |
+				((bus_state & Line::Message)		? 0x10 : 0x00) |
+				((bus_state & Line::Control)		? 0x08 : 0x00) |
+				((bus_state & Line::Input)			? 0x04 : 0x00) |
+				((bus_state & Line::SelectTarget)	? 0x02 : 0x00) |
+				((bus_state & Line::Parity)			? 0x01 : 0x00);
+//			LOG("[SCSI 4] Get current bus state: " << PADHEX(2) << int(result));
+			return result;
+		}
+
+		case 5: {
+			const auto bus_state = bus_.get_state();
+			const bool phase_matches =
+				(target_output() & (Line::Message | Line::Control | Line::Input)) ==
+				(bus_state & (Line::Message | Line::Control | Line::Input));
+
+			const uint8_t result =
+				/* b7 = end of DMA */
+				((dma_request_ && state_ == ExecutionState::PerformingDMA) ? 0x40 : 0x00)	|
+				/* b5 = parity error */
+				/* b4 = IRQ active */
+				(phase_matches ? 0x08 : 0x00)	|
+				/* b2 = busy error */
+				((bus_state & Line::Attention) ? 0x02 : 0x00) |
+				((bus_state & Line::Acknowledge) ? 0x01 : 0x00);
+//			LOG("[SCSI 5] Get bus and status: " << PADHEX(2) << int(result));
+			return result;
+		}
+
+		case 6:
+//			LOG("[SCSI 6] Get input data");
+		return 0xff;
+
+		case 7:
+//			LOG("[SCSI 7] Reset parity/interrupt");
+		return 0xff;
+	}
+	return 0;
+}
+
+SCSI::BusState NCR5380::target_output() {
+	SCSI::BusState output = SCSI::DefaultBusState;
+	if(target_command_ & 0x08) output |= Line::Request;
+	if(target_command_ & 0x04) output |= Line::Message;
+	if(target_command_ & 0x02) output |= Line::Control;
+	if(target_command_ & 0x01) output |= Line::Input;
+	return output;
+}
+
+void NCR5380::update_control_output() {
+	bus_output_ &= ~(Line::Request | Line::Message | Line::Control | Line::Input | Line::Acknowledge | Line::Attention);
+	if(mode_ & 0x40) {
+		// This is a target; C/D, I/O, /MSG and /REQ are signalled on the bus.
+		bus_output_ |= target_output();
+	} else {
+		// This is an initiator; /ATN and /ACK are signalled on the bus.
+		if(
+			(initiator_command_ & 0x10) ||
+			(state_ == ExecutionState::PerformingDMA && dma_acknowledge_)
+		) bus_output_ |= Line::Acknowledge;
+		if(initiator_command_ & 0x02) bus_output_ |= Line::Attention;
+	}
+}
+
+void NCR5380::scsi_bus_did_change(SCSI::Bus *, SCSI::BusState new_state, double time_since_change) {
+	switch(state_) {
+		default: break;
+
+		/*
+			Official documentation:
+
+				Arbitration is accomplished using a bus-free filter to continuously monitor BSY.
+				If BSY remains inactive for at least 400 nsec then the SCSI bus is considered free
+				and arbitration may begin. Arbitration will begin if the bus is free, SEL is inactive
+				and the ARBITRATION bit (port 2, bit 0) is active. Once arbitration has begun
+				(BSY asserted), an arbitration delay of 2.2 /Lsec must elapse before the data bus
+				can be examined to deter- mine if arbitration has been won. This delay must be
+				implemented in the controlling software driver.
+
+			Personal notes:
+
+				I'm discounting that "arbitratation is accomplished" opening, and assuming that what needs
+				to happen is:
+
+					(i) wait for BSY to be inactive;
+					(ii) count 400 nsec;
+					(iii) check that BSY and SEL are inactive.
+		*/
+
+		case ExecutionState::WaitingForBusy:
+			if(!(new_state & SCSI::Line::Busy) || time_since_change < SCSI::DeskewDelay) return;
+			state_ = ExecutionState::WatchingBusy;
+			[[fallthrough]];
+
+		case ExecutionState::WatchingBusy:
+			if(!(new_state & SCSI::Line::Busy)) {
+				lost_arbitration_ = true;
+				set_execution_state(ExecutionState::None);
+			}
+
+			// Check for having hit 400ns (more or less) since BSY was inactive.
+			if(time_since_change >= SCSI::BusSettleDelay) {
+//				arbitration_in_progress_ = false;
+				if(new_state & SCSI::Line::SelectTarget) {
+					lost_arbitration_ = true;
+					set_execution_state(ExecutionState::None);
+				} else {
+					bus_output_ &= ~SCSI::Line::Busy;
+					set_execution_state(ExecutionState::None);
+				}
+			}
+
+			/* TODO: there's a bug here, given that the dropping of Busy isn't communicated onward. */
+		break;
+
+		case ExecutionState::PerformingDMA:
+			if(time_since_change < SCSI::DeskewDelay) return;
+
+			// Signal a DMA request if the request line is active, i.e. meaningful data is
+			// on the bus, and this device hasn't yet acknowledged it.
+			switch(new_state & (SCSI::Line::Request | SCSI::Line::Acknowledge)) {
+				case 0:
+					dma_request_ = false;
+				break;
+				case SCSI::Line::Request:
+					dma_request_ = true;
+				break;
+				case SCSI::Line::Request | SCSI::Line::Acknowledge:
+					dma_request_ = false;
+				break;
+				case SCSI::Line::Acknowledge:
+					dma_acknowledge_ = false;
+					dma_request_ = false;
+					update_control_output();
+					bus_.set_device_output(device_id_, bus_output_);
+				break;
+			}
+		break;
+	}
+}
+
+void NCR5380::set_execution_state(ExecutionState state) {
+	state_ = state;
+	if(state != ExecutionState::PerformingDMA) dma_operation_ = DMAOperation::Ready;
+}

Components/5380/ncr5380.hpp

@@ -0,0 +1,75 @@
+//
+//  ncr5380.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 10/08/2019.
+//  Copyright © 2019 Thomas Harte. All rights reserved.
+//
+
+#ifndef ncr5380_hpp
+#define ncr5380_hpp
+
+#include <cstdint>
+
+#include "../../Storage/MassStorage/SCSI/SCSI.hpp"
+
+
+namespace NCR {
+namespace NCR5380 {
+
+/*!
+	Models the NCR 5380, a SCSI interface chip.
+*/
+class NCR5380 final: public SCSI::Bus::Observer {
+	public:
+		NCR5380(SCSI::Bus &bus, int clock_rate);
+
+		/*! Writes @c value to @c address.  */
+		void write(int address, uint8_t value, bool dma_acknowledge = false);
+
+		/*! Reads from @c address. */
+		uint8_t read(int address, bool dma_acknowledge = false);
+
+	private:
+		SCSI::Bus &bus_;
+
+		const int clock_rate_;
+		size_t device_id_;
+
+		SCSI::BusState bus_output_ = SCSI::DefaultBusState;
+		SCSI::BusState expected_phase_ = SCSI::DefaultBusState;
+		uint8_t mode_ = 0xff;
+		uint8_t initiator_command_ = 0xff;
+		uint8_t data_bus_ = 0xff;
+		uint8_t target_command_ = 0xff;
+		bool test_mode_ = false;
+		bool assert_data_bus_ = false;
+		bool dma_request_ = false;
+		bool dma_acknowledge_ = false;
+
+		enum class ExecutionState {
+			None,
+			WaitingForBusy,
+			WatchingBusy,
+			PerformingDMA,
+		} state_ = ExecutionState::None;
+		enum class DMAOperation {
+			Ready,
+			Send,
+			TargetReceive,
+			InitiatorReceive
+		} dma_operation_ = DMAOperation::Ready;
+		bool lost_arbitration_ = false, arbitration_in_progress_ = false;
+
+		void set_execution_state(ExecutionState state);
+
+		SCSI::BusState target_output();
+		void update_control_output();
+
+		void scsi_bus_did_change(SCSI::Bus *, SCSI::BusState new_state, double time_since_change) final;
+};
+
+}
+}
+
+#endif /* ncr5380_hpp */

Components/6522/6522.hpp

@@ -37,22 +37,22 @@ enum Line {
 class PortHandler {
 	public:
 		/// Requests the current input value of @c port from the port handler.
-		uint8_t get_port_input(Port port)										{	return 0xff;	}
+	uint8_t get_port_input([[maybe_unused]] Port port)										{	return 0xff;	}
 
 		/// Sets the current output value of @c port and provides @c direction_mask, indicating which pins are marked as output.
-		void set_port_output(Port port, uint8_t value, uint8_t direction_mask)	{}
+		void set_port_output([[maybe_unused]] Port port, [[maybe_unused]] uint8_t value, [[maybe_unused]] uint8_t direction_mask)	{}
 
 		/// Sets the current logical output level for line @c line on port @c port.
-		void set_control_line_output(Port port, Line line, bool value)			{}
+		void set_control_line_output([[maybe_unused]] Port port, [[maybe_unused]] Line line, [[maybe_unused]] bool value)			{}
 
 		/// Sets the current logical value of the interrupt line.
-		void set_interrupt_status(bool status)									{}
+		void set_interrupt_status([[maybe_unused]] bool status)									{}
 
 		/// Provides a measure of time elapsed between other calls.
-		void run_for(HalfCycles duration)										{}
+		void run_for([[maybe_unused]] HalfCycles duration)										{}
 
 		/// Receives passed-on flush() calls from the 6522.
-		void flush()															{}
+		void flush()																			{}
 };
 
 /*!
@@ -94,10 +94,10 @@ template <class T> class MOS6522: public MOS6522Storage {
 		MOS6522(const MOS6522 &) = delete;
 
 		/*! Sets a register value. */
-		void set_register(int address, uint8_t value);
+		void write(int address, uint8_t value);
 
 		/*! Gets a register value. */
-		uint8_t get_register(int address);
+		uint8_t read(int address);
 
 		/*! @returns the bus handler. */
 		T &bus_handler();
@@ -112,7 +112,7 @@ template <class T> class MOS6522: public MOS6522Storage {
 		void run_for(const Cycles cycles);
 
 		/// @returns @c true if the IRQ line is currently active; @c false otherwise.
-		bool get_interrupt_line();
+		bool get_interrupt_line() const;
 
 		/// Updates the port handler to the current time and then requests that it flush.
 		void flush();
@@ -128,13 +128,14 @@ template <class T> class MOS6522: public MOS6522Storage {
 
 		void access(int address);
 
-		uint8_t get_port_input(Port port, uint8_t output_mask, uint8_t output);
+		uint8_t get_port_input(Port port, uint8_t output_mask, uint8_t output, uint8_t timer_mask);
 		inline void reevaluate_interrupts();
 
 		/// Sets the current intended output value for the port and line;
 		/// if this affects the visible output, it will be passed to the handler.
 		void set_control_line_output(Port port, Line line, LineState value);
 		void evaluate_cb2_output();
+		void evaluate_port_b_output();
 };
 
 }

Components/6522/Implementation/6522Implementation.hpp

@@ -8,6 +8,10 @@
 
 #include "../../../Outputs/Log.hpp"
 
+// As-yet unimplemented (incomplete list):
+//
+//	PB6 count-down mode for timer 2.
+
 namespace MOS {
 namespace MOS6522 {
 
@@ -30,22 +34,22 @@ template <typename T> void MOS6522<T>::access(int address) {
 	}
 }
 
-template <typename T> void MOS6522<T>::set_register(int address, uint8_t value) {
+template <typename T> void MOS6522<T>::write(int address, uint8_t value) {
 	address &= 0xf;
 	access(address);
 	switch(address) {
-		case 0x0:	// Write Port B.
+		case 0x0:	// Write Port B. ('ORB')
 			// Store locally and communicate outwards.
 			registers_.output[1] = value;
 
 			bus_handler_.run_for(time_since_bus_handler_call_.flush<HalfCycles>());
-			bus_handler_.set_port_output(Port::B, value, registers_.data_direction[1]);
+			evaluate_port_b_output();
 
 			registers_.interrupt_flags &= ~(InterruptFlag::CB1ActiveEdge | ((registers_.peripheral_control&0x20) ? 0 : InterruptFlag::CB2ActiveEdge));
 			reevaluate_interrupts();
 		break;
 		case 0xf:
-		case 0x1:	// Write Port A.
+		case 0x1:	// Write Port A. ('ORA')
 			registers_.output[0] = value;
 
 			bus_handler_.run_for(time_since_bus_handler_call_.flush<HalfCycles>());
@@ -59,36 +63,52 @@ template <typename T> void MOS6522<T>::set_register(int address, uint8_t value)
 			reevaluate_interrupts();
 		break;
 
-		case 0x2:	// Port B direction.
+		case 0x2:	// Port B direction ('DDRB').
 			registers_.data_direction[1] = value;
 		break;
-		case 0x3:	// Port A direction.
+		case 0x3:	// Port A direction ('DDRA').
 			registers_.data_direction[0] = value;
 		break;
 
 		// Timer 1
-		case 0x6:	case 0x4:	registers_.timer_latch[0] = (registers_.timer_latch[0]&0xff00) | value;	break;
-		case 0x5:	case 0x7:
-			registers_.timer_latch[0] = (registers_.timer_latch[0]&0x00ff) | static_cast<uint16_t>(value << 8);
-			registers_.interrupt_flags &= ~InterruptFlag::Timer1;
-			if(address == 0x05) {
-				registers_.next_timer[0] = registers_.timer_latch[0];
-				timer_is_running_[0] = true;
+		case 0x6:	case 0x4:	// ('T1L-L' and 'T1C-L')
+			registers_.timer_latch[0] = (registers_.timer_latch[0]&0xff00) | value;
+		break;
+		case 0x7:	// Timer 1 latch, high ('T1L-H').
+			registers_.timer_latch[0] = (registers_.timer_latch[0]&0x00ff) | uint16_t(value << 8);
+		break;
+		case 0x5:	// Timer 1 counter, high ('T1C-H').
+			// Fill latch.
+			registers_.timer_latch[0] = (registers_.timer_latch[0]&0x00ff) | uint16_t(value << 8);
+
+			// Restart timer.
+			registers_.next_timer[0] = registers_.timer_latch[0];
+			timer_is_running_[0] = true;
+
+			// If PB7 output mode is active, set it low.
+			if(timer1_is_controlling_pb7()) {
+				registers_.timer_port_b_output &= 0x7f;
+				evaluate_port_b_output();
 			}
+
+			// Clear existing interrupt flag.
+			registers_.interrupt_flags &= ~InterruptFlag::Timer1;
 			reevaluate_interrupts();
 		break;
 
 		// Timer 2
-		case 0x8:	registers_.timer_latch[1] = value;	break;
-		case 0x9:
+		case 0x8:	// ('T2C-L')
+			registers_.timer_latch[1] = value;
+		break;
+		case 0x9:	// ('T2C-H')
 			registers_.interrupt_flags &= ~InterruptFlag::Timer2;
-			registers_.next_timer[1] = registers_.timer_latch[1] | static_cast<uint16_t>(value << 8);
+			registers_.next_timer[1] = registers_.timer_latch[1] | uint16_t(value << 8);
 			timer_is_running_[1] = true;
 			reevaluate_interrupts();
 		break;
 
 		// Shift
-		case 0xa:
+		case 0xa:	// ('SR')
 			registers_.shift = value;
 			shift_bits_remaining_ = 8;
 			registers_.interrupt_flags &= ~InterruptFlag::ShiftRegister;
@@ -96,11 +116,18 @@ template <typename T> void MOS6522<T>::set_register(int address, uint8_t value)
 		break;
 
 		// Control
-		case 0xb:
+		case 0xb:	// Auxiliary control ('ACR').
 			registers_.auxiliary_control = value;
 			evaluate_cb2_output();
+
+			// This is a bit of a guess: reset the timer-based PB7 output to its default high level
+			// any timer that timer-linked PB7 output is disabled.
+			if(!timer1_is_controlling_pb7()) {
+				registers_.timer_port_b_output |= 0x80;
+			}
+			evaluate_port_b_output();
 		break;
-		case 0xc: {
+		case 0xc: {	// Peripheral control ('PCR').
 //			const auto old_peripheral_control = registers_.peripheral_control;
 			registers_.peripheral_control = value;
 
@@ -141,11 +168,11 @@ template <typename T> void MOS6522<T>::set_register(int address, uint8_t value)
 		} break;
 
 		// Interrupt control
-		case 0xd:
+		case 0xd:	// Interrupt flag regiser ('IFR').
 			registers_.interrupt_flags &= ~value;
 			reevaluate_interrupts();
 		break;
-		case 0xe:
+		case 0xe:	// Interrupt enable register ('IER').
 			if(value&0x80)
 				registers_.interrupt_enable |= value;
 			else
@@ -155,58 +182,59 @@ template <typename T> void MOS6522<T>::set_register(int address, uint8_t value)
 	}
 }
 
-template <typename T> uint8_t MOS6522<T>::get_register(int address) {
+template <typename T> uint8_t MOS6522<T>::read(int address) {
 	address &= 0xf;
 	access(address);
 	switch(address) {
-		case 0x0:
+		case 0x0:	// Read Port B ('IRB').
 			registers_.interrupt_flags &= ~(InterruptFlag::CB1ActiveEdge | InterruptFlag::CB2ActiveEdge);
 			reevaluate_interrupts();
-		return get_port_input(Port::B, registers_.data_direction[1], registers_.output[1]);
+		return get_port_input(Port::B, registers_.data_direction[1], registers_.output[1], registers_.auxiliary_control & 0x80);
 		case 0xf:
-		case 0x1:
+		case 0x1:	// Read Port A ('IRA').
 			registers_.interrupt_flags &= ~(InterruptFlag::CA1ActiveEdge | InterruptFlag::CA2ActiveEdge);
 			reevaluate_interrupts();
-		return get_port_input(Port::A, registers_.data_direction[0], registers_.output[0]);
+		return get_port_input(Port::A, registers_.data_direction[0], registers_.output[0], 0);
 
-		case 0x2:	return registers_.data_direction[1];
-		case 0x3:	return registers_.data_direction[0];
+		case 0x2:	return registers_.data_direction[1];	// Port B direction ('DDRB').
+		case 0x3:	return registers_.data_direction[0];	// Port A direction ('DDRA').
 
 		// Timer 1
-		case 0x4:
+		case 0x4:	// Timer 1 low-order latches ('T1L-L').
 			registers_.interrupt_flags &= ~InterruptFlag::Timer1;
 			reevaluate_interrupts();
 		return registers_.timer[0] & 0x00ff;
-		case 0x5:	return registers_.timer[0] >> 8;
-		case 0x6:	return registers_.timer_latch[0] & 0x00ff;
-		case 0x7:	return registers_.timer_latch[0] >> 8;
+		case 0x5:	return registers_.timer[0] >> 8;			// Timer 1 high-order counter ('T1C-H')
+		case 0x6:	return registers_.timer_latch[0] & 0x00ff;	// Timer 1 low-order latches ('T1L-L').
+		case 0x7:	return registers_.timer_latch[0] >> 8;		// Timer 1 high-order latches ('T1L-H').
 
 		// Timer 2
-		case 0x8:
+		case 0x8:	// Timer 2 low-order counter ('T2C-L').
 			registers_.interrupt_flags &= ~InterruptFlag::Timer2;
 			reevaluate_interrupts();
 		return registers_.timer[1] & 0x00ff;
-		case 0x9:	return registers_.timer[1] >> 8;
+		case 0x9:	return registers_.timer[1] >> 8;	// Timer 2 high-order counter ('T2C-H').
 
-		case 0xa:
+		case 0xa:	// Shift register ('SR').
 			shift_bits_remaining_ = 8;
 			registers_.interrupt_flags &= ~InterruptFlag::ShiftRegister;
 			reevaluate_interrupts();
 		return registers_.shift;
 
-		case 0xb:	return registers_.auxiliary_control;
-		case 0xc:	return registers_.peripheral_control;
+		case 0xb:	return registers_.auxiliary_control;	// Auxiliary control ('ACR').
+		case 0xc:	return registers_.peripheral_control;	// Peripheral control ('PCR').
 
-		case 0xd:	return registers_.interrupt_flags | (get_interrupt_line() ? 0x80 : 0x00);
-		case 0xe:	return registers_.interrupt_enable | 0x80;
+		case 0xd:	return registers_.interrupt_flags | (get_interrupt_line() ? 0x80 : 0x00);	// Interrupt flag register ('IFR').
+		case 0xe:	return registers_.interrupt_enable | 0x80;									// Interrupt enable register ('IER').
 	}
 
 	return 0xff;
 }
 
-template <typename T> uint8_t MOS6522<T>::get_port_input(Port port, uint8_t output_mask, uint8_t output) {
+template <typename T> uint8_t MOS6522<T>::get_port_input(Port port, uint8_t output_mask, uint8_t output, uint8_t timer_mask) {
 	bus_handler_.run_for(time_since_bus_handler_call_.flush<HalfCycles>());
 	const uint8_t input = bus_handler_.get_port_input(port);
+	output = (output & ~timer_mask) | (registers_.timer_port_b_output & timer_mask);
 	return (input & ~output_mask) | (output & output_mask);
 }
 
@@ -276,16 +304,19 @@ template <typename T> void MOS6522<T>::do_phase2() {
 		registers_.timer_needs_reload = false;
 		registers_.timer[0] = registers_.timer_latch[0];
 	} else {
-		registers_.timer[0] --;
+		-- registers_.timer[0];
 	}
 
-	registers_.timer[1] --;
+	// Count down timer 2 if it is in timed interrupt mode (i.e. auxiliary control bit 5 is clear).
+	registers_.timer[1] -= timer2_clock_decrement();
+
+	// TODO: can eliminate conditional branches here.
 	if(registers_.next_timer[0] >= 0) {
-		registers_.timer[0] = static_cast<uint16_t>(registers_.next_timer[0]);
+		registers_.timer[0] = uint16_t(registers_.next_timer[0]);
 		registers_.next_timer[0] = -1;
 	}
 	if(registers_.next_timer[1] >= 0) {
-		registers_.timer[1] = static_cast<uint16_t>(registers_.next_timer[1]);
+		registers_.timer[1] = uint16_t(registers_.next_timer[1]);
 		registers_.next_timer[1] = -1;
 	}
 
@@ -330,23 +361,32 @@ template <typename T> void MOS6522<T>::do_phase1() {
 		reevaluate_interrupts();
 
 		// Determine whether to reload.
-		if(registers_.auxiliary_control&0x40)
+		if(timer1_is_continuous())
 			registers_.timer_needs_reload = true;
 		else
 			timer_is_running_[0] = false;
 
 		// Determine whether to toggle PB7.
-		if(registers_.auxiliary_control&0x80) {
-			registers_.output[1] ^= 0x80;
+		if(timer1_is_controlling_pb7()) {
+			registers_.timer_port_b_output ^= 0x80;
 			bus_handler_.run_for(time_since_bus_handler_call_.flush<HalfCycles>());
-			bus_handler_.set_port_output(Port::B, registers_.output[1], registers_.data_direction[1]);
+			evaluate_port_b_output();
 		}
 	}
 }
 
+template <typename T> void MOS6522<T>::evaluate_port_b_output() {
+	// Apply current timer-linked PB7 output if any atop the stated output.
+	const uint8_t timer_control_bit = registers_.auxiliary_control & 0x80;
+	bus_handler_.set_port_output(
+		Port::B,
+		(registers_.output[1] & (0xff ^ timer_control_bit)) | timer_control_bit,
+		registers_.data_direction[1] | timer_control_bit);
+}
+
 /*! Runs for a specified number of half cycles. */
 template <typename T> void MOS6522<T>::run_for(const HalfCycles half_cycles) {
-	int number_of_half_cycles = half_cycles.as_int();
+	auto number_of_half_cycles = half_cycles.as_integral();
 	if(!number_of_half_cycles) return;
 
 	if(is_phase2_) {
@@ -375,7 +415,7 @@ template <typename T> void MOS6522<T>::flush() {
 
 /*! Runs for a specified number of cycles. */
 template <typename T> void MOS6522<T>::run_for(const Cycles cycles) {
-	int number_of_cycles = cycles.as_int();
+	auto number_of_cycles = cycles.as_integral();
 	while(number_of_cycles--) {
 		do_phase1();
 		do_phase2();
@@ -383,9 +423,9 @@ template <typename T> void MOS6522<T>::run_for(const Cycles cycles) {
 }
 
 /*! @returns @c true if the IRQ line is currently active; @c false otherwise. */
-template <typename T> bool MOS6522<T>::get_interrupt_line() {
+template <typename T> bool MOS6522<T>::get_interrupt_line() const {
 	uint8_t interrupt_status = registers_.interrupt_flags & registers_.interrupt_enable & 0x7f;
-	return !!interrupt_status;
+	return interrupt_status;
 }
 
 template <typename T> void MOS6522<T>::evaluate_cb2_output() {
@@ -438,10 +478,11 @@ template <typename T> void MOS6522<T>::shift_in() {
 }
 
 template <typename T> void MOS6522<T>::shift_out() {
-	// When shifting out, the shift register rotates rather than strictly shifts.
-	// TODO: is that true for all modes?
-	if(shift_mode() == ShiftMode::OutUnderT2FreeRunning || shift_bits_remaining_) {
-		registers_.shift = uint8_t((registers_.shift << 1) | (registers_.shift >> 7));
+	const bool is_free_running = shift_mode() == ShiftMode::OutUnderT2FreeRunning;
+	if(is_free_running || shift_bits_remaining_) {
+		// Recirculate bits only if in free-running mode (?)
+		const uint8_t incoming_bit = (registers_.shift >> 7) * is_free_running;
+		registers_.shift = uint8_t(registers_.shift << 1) | incoming_bit;
 		evaluate_cb2_output();
 
 		--shift_bits_remaining_;

Components/6522/Implementation/6522Storage.hpp

@@ -34,7 +34,9 @@ class MOS6522Storage {
 			uint8_t peripheral_control = 0;
 			uint8_t interrupt_flags = 0;
 			uint8_t interrupt_enable = 0;
+
 			bool timer_needs_reload = false;
+			uint8_t timer_port_b_output = 0xff;
 		} registers_;
 
 		// Control state.
@@ -79,12 +81,30 @@ class MOS6522Storage {
 			OutUnderPhase2 = 6,
 			OutUnderCB1 = 7
 		};
-		ShiftMode shift_mode() const {
-			return ShiftMode((registers_.auxiliary_control >> 2) & 7);
+		bool timer1_is_controlling_pb7() const {
+			return registers_.auxiliary_control & 0x80;
+		}
+		bool timer1_is_continuous() const {
+			return registers_.auxiliary_control & 0x40;
 		}
 		bool is_shifting_out() const {
 			return registers_.auxiliary_control & 0x10;
 		}
+		int timer2_clock_decrement() const {
+			return 1 ^ ((registers_.auxiliary_control >> 5)&1);
+		}
+		int timer2_pb6_decrement() const {
+			return (registers_.auxiliary_control >> 5)&1;
+		}
+		ShiftMode shift_mode() const {
+			return ShiftMode((registers_.auxiliary_control >> 2) & 7);
+		}
+		bool portb_is_latched() const {
+			return registers_.auxiliary_control & 0x02;
+		}
+		bool port1_is_latched() const {
+			return registers_.auxiliary_control & 0x01;
+		}
 };
 
 }

Components/6522/Implementation/IRQDelegatePortHandler.cpp

@@ -14,6 +14,6 @@ void IRQDelegatePortHandler::set_interrupt_delegate(Delegate *delegate) {
 	delegate_ = delegate;
 }
 
-void IRQDelegatePortHandler::set_interrupt_status(bool new_status) {
+void IRQDelegatePortHandler::set_interrupt_status(bool) {
 	if(delegate_) delegate_->mos6522_did_change_interrupt_status(this);
 }

Components/6532/6532.hpp

@@ -32,7 +32,7 @@ template <class T> class MOS6532 {
 		inline void set_ram(uint16_t address, uint8_t value)	{	ram_[address&0x7f] = value;		}
 		inline uint8_t get_ram(uint16_t address)				{	return ram_[address & 0x7f];	}
 
-		inline void set_register(int address, uint8_t value) {
+		inline void write(int address, uint8_t value) {
 			const uint8_t decodedAddress = address & 0x07;
 			switch(decodedAddress) {
 				// Port output
@@ -51,7 +51,7 @@ template <class T> class MOS6532 {
 				case 0x04: case 0x05: case 0x06: case 0x07:
 					if(address & 0x10) {
 						timer_.writtenShift = timer_.activeShift = (decodedAddress - 0x04) * 3 + (decodedAddress / 0x07);	// i.e. 0, 3, 6, 10
-						timer_.value = (static_cast<unsigned int>(value) << timer_.activeShift) ;
+						timer_.value = (unsigned(value) << timer_.activeShift) ;
 						timer_.interrupt_enabled = !!(address&0x08);
 						interrupt_status_ &= ~InterruptFlag::Timer;
 						evaluate_interrupts();
@@ -63,7 +63,7 @@ template <class T> class MOS6532 {
 			}
 		}
 
-		inline uint8_t get_register(int address) {
+		inline uint8_t read(int address) {
 			const uint8_t decodedAddress = address & 0x7;
 			switch(decodedAddress) {
 				// Port input
@@ -79,7 +79,7 @@ template <class T> class MOS6532 {
 
 				// Timer and interrupt control
 				case 0x04: case 0x06: {
-					uint8_t value = static_cast<uint8_t>(timer_.value >> timer_.activeShift);
+					uint8_t value = uint8_t(timer_.value >> timer_.activeShift);
 					timer_.interrupt_enabled = !!(address&0x08);
 					interrupt_status_ &= ~InterruptFlag::Timer;
 					evaluate_interrupts();
@@ -107,7 +107,7 @@ template <class T> class MOS6532 {
 		}
 
 		inline void run_for(const Cycles cycles) {
-			unsigned int number_of_cycles = static_cast<unsigned int>(cycles.as_int());
+			unsigned int number_of_cycles = unsigned(cycles.as_integral());
 
 			// permit counting _to_ zero; counting _through_ zero initiates the other behaviour
 			if(timer_.value >= number_of_cycles) {
@@ -122,7 +122,7 @@ template <class T> class MOS6532 {
 		}
 
 		MOS6532() {
-			timer_.value = static_cast<unsigned int>((rand() & 0xff) << 10);
+			timer_.value = unsigned((rand() & 0xff) << 10);
 		}
 
 		inline void set_port_did_change(int port) {
@@ -142,7 +142,7 @@ template <class T> class MOS6532 {
 			}
 		}
 
-		inline bool get_inerrupt_line() {
+		inline bool get_inerrupt_line() const {
 			return interrupt_line_;
 		}
 
@@ -173,9 +173,11 @@ template <class T> class MOS6532 {
 		bool interrupt_line_ = false;
 
 		// expected to be overridden
-		uint8_t get_port_input(int port)										{	return 0xff;	}
-		void set_port_output(int port, uint8_t value, uint8_t output_mask)		{}
-		void set_irq_line(bool new_value)										{}
+		void set_port_output([[maybe_unused]] int port, [[maybe_unused]] uint8_t value, [[maybe_unused]] uint8_t output_mask) {}
+		uint8_t get_port_input([[maybe_unused]] int port) {
+			return 0xff;
+		}
+		void set_irq_line(bool) {}
 
 		inline void evaluate_interrupts() {
 			interrupt_line_ =

Components/6560/6560.cpp

@@ -17,13 +17,13 @@ AudioGenerator::AudioGenerator(Concurrency::DeferringAsyncTaskQueue &audio_queue
 
 
 void AudioGenerator::set_volume(uint8_t volume) {
-	audio_queue_.defer([=]() {
-		volume_ = static_cast<int16_t>(volume) * range_multiplier_;
+	audio_queue_.defer([this, volume]() {
+		volume_ = int16_t(volume) * range_multiplier_;
 	});
 }
 
 void AudioGenerator::set_control(int channel, uint8_t value) {
-	audio_queue_.defer([=]() {
+	audio_queue_.defer([this, channel, value]() {
 		control_registers_[channel] = value;
 	});
 }
@@ -98,7 +98,7 @@ static uint8_t noise_pattern[] = {
 
 #define shift(r) shift_registers_[r] = (shift_registers_[r] << 1) | (((shift_registers_[r]^0x80)&control_registers_[r]) >> 7)
 #define increment(r) shift_registers_[r] = (shift_registers_[r]+1)%8191
-#define update(r, m, up) counters_[r]++; if((counters_[r] >> m) == 0x80) { up(r); counters_[r] = static_cast<unsigned int>(control_registers_[r]&0x7f) << m; }
+#define update(r, m, up) counters_[r]++; if((counters_[r] >> m) == 0x80) { up(r); counters_[r] = unsigned(control_registers_[r]&0x7f) << m; }
 // Note on slightly askew test: as far as I can make out, if the value in the register is 0x7f then what's supposed to happen
 // is that the 0x7f is loaded, on the next clocked cycle the Vic spots a 0x7f, pumps the output, reloads, etc. No increment
 // ever occurs. It's conditional. I don't really want two conditionals if I can avoid it so I'm incrementing regardless and
@@ -114,7 +114,7 @@ void AudioGenerator::get_samples(std::size_t number_of_samples, int16_t *target)
 
 		// this sums the output of all three sounds channels plus a DC offset for volume;
 		// TODO: what's the real ratio of this stuff?
-		target[c] = static_cast<int16_t>(
+		target[c] = int16_t(
 			(shift_registers_[0]&1) +
 			(shift_registers_[1]&1) +
 			(shift_registers_[2]&1) +
@@ -133,7 +133,7 @@ void AudioGenerator::skip_samples(std::size_t number_of_samples) {
 }
 
 void AudioGenerator::set_sample_volume_range(std::int16_t range) {
-	range_multiplier_ = static_cast<int16_t>(range / 64);
+	range_multiplier_ = int16_t(range / 64);
 }
 
 #undef shift

Components/6560/6560.hpp

@@ -30,6 +30,7 @@ class AudioGenerator: public ::Outputs::Speaker::SampleSource {
 		void get_samples(std::size_t number_of_samples, int16_t *target);
 		void skip_samples(std::size_t number_of_samples);
 		void set_sample_volume_range(std::int16_t range);
+		static constexpr bool get_is_stereo() { return false; }
 
 	private:
 		Concurrency::DeferringAsyncTaskQueue &audio_queue_;
@@ -42,7 +43,7 @@ class AudioGenerator: public ::Outputs::Speaker::SampleSource {
 };
 
 struct BusHandler {
-	void perform_read(uint16_t address, uint8_t *pixel_data, uint8_t *colour_data) {
+	void perform_read([[maybe_unused]] uint16_t address, [[maybe_unused]] uint8_t *pixel_data, [[maybe_unused]] uint8_t *colour_data) {
 		*pixel_data = 0xff;
 		*colour_data = 0xff;
 	}
@@ -58,7 +59,7 @@ enum class OutputMode {
 	To run the VIC for a cycle, the caller should call @c get_address, make the requested bus access
 	and call @c set_graphics_value with the result.
 
-	@c set_register and @c get_register provide register access.
+	@c write and @c read provide register access.
 */
 template <class BusHandler> class MOS6560 {
 	public:
@@ -80,12 +81,14 @@ template <class BusHandler> class MOS6560 {
 		}
 
 		void set_clock_rate(double clock_rate) {
-			speaker_.set_input_rate(static_cast<float>(clock_rate / 4.0));
+			speaker_.set_input_rate(float(clock_rate / 4.0));
 		}
 
-		void set_scan_target(Outputs::Display::ScanTarget *scan_target)		{ crt_.set_scan_target(scan_target); 	}
-		void set_display_type(Outputs::Display::DisplayType display_type)	{ crt_.set_display_type(display_type); 	}
-		Outputs::Speaker::Speaker *get_speaker() { return &speaker_; }
+		void set_scan_target(Outputs::Display::ScanTarget *scan_target)		{ crt_.set_scan_target(scan_target); 			}
+		Outputs::Display::ScanStatus get_scaled_scan_status() const			{ return crt_.get_scaled_scan_status() / 4.0f;	}
+		void set_display_type(Outputs::Display::DisplayType display_type)	{ crt_.set_display_type(display_type); 			}
+		Outputs::Display::DisplayType get_display_type() const				{ return crt_.get_display_type(); 				}
+		Outputs::Speaker::Speaker *get_speaker()	 						{ return &speaker_; 							}
 
 		void set_high_frequency_cutoff(float cutoff) {
 			speaker_.set_high_frequency_cutoff(cutoff);
@@ -170,7 +173,7 @@ template <class BusHandler> class MOS6560 {
 			// keep track of the amount of time since the speaker was updated; lazy updates are applied
 			cycles_since_speaker_update_ += cycles;
 
-			int number_of_cycles = cycles.as_int();
+			auto number_of_cycles = cycles.as_integral();
 			while(number_of_cycles--) {
 				// keep an old copy of the vertical count because that test is a cycle later than the actual changes
 				int previous_vertical_counter = vertical_counter_;
@@ -232,7 +235,7 @@ template <class BusHandler> class MOS6560 {
 					if(column_counter_&1) {
 						fetch_address = registers_.character_cell_start_address + (character_code_*(registers_.tall_characters ? 16 : 8)) + current_character_row_;
 					} else {
-						fetch_address = static_cast<uint16_t>(registers_.video_matrix_start_address + video_matrix_address_counter_);
+						fetch_address = uint16_t(registers_.video_matrix_start_address + video_matrix_address_counter_);
 						video_matrix_address_counter_++;
 						if(
 							(current_character_row_ == 15) ||
@@ -353,7 +356,7 @@ template <class BusHandler> class MOS6560 {
 		/*!
 			Writes to a 6560 register.
 		*/
-		void set_register(int address, uint8_t value) {
+		void write(int address, uint8_t value) {
 			address &= 0xf;
 			registers_.direct_values[address] = value;
 			switch(address) {
@@ -368,7 +371,7 @@ template <class BusHandler> class MOS6560 {
 
 				case 0x2:
 					registers_.number_of_columns = value & 0x7f;
-					registers_.video_matrix_start_address = static_cast<uint16_t>((registers_.video_matrix_start_address & 0x3c00) | ((value & 0x80) << 2));
+					registers_.video_matrix_start_address = uint16_t((registers_.video_matrix_start_address & 0x3c00) | ((value & 0x80) << 2));
 				break;
 
 				case 0x3:
@@ -377,8 +380,8 @@ template <class BusHandler> class MOS6560 {
 				break;
 
 				case 0x5:
-					registers_.character_cell_start_address = static_cast<uint16_t>((value & 0x0f) << 10);
-					registers_.video_matrix_start_address = static_cast<uint16_t>((registers_.video_matrix_start_address & 0x0200) | ((value & 0xf0) << 6));
+					registers_.character_cell_start_address = uint16_t((value & 0x0f) << 10);
+					registers_.video_matrix_start_address = uint16_t((registers_.video_matrix_start_address & 0x0200) | ((value & 0xf0) << 6));
 				break;
 
 				case 0xa:
@@ -417,11 +420,11 @@ template <class BusHandler> class MOS6560 {
 		/*
 			Reads from a 6560 register.
 		*/
-		uint8_t get_register(int address) {
+		uint8_t read(int address) const {
 			address &= 0xf;
 			switch(address) {
 				default: return registers_.direct_values[address];
-				case 0x03: return static_cast<uint8_t>(raster_value() << 7) | (registers_.direct_values[3] & 0x7f);
+				case 0x03: return uint8_t(raster_value() << 7) | (registers_.direct_values[3] & 0x7f);
 				case 0x04: return (raster_value() >> 1) & 0xff;
 			}
 		}
@@ -442,28 +445,28 @@ template <class BusHandler> class MOS6560 {
 		// register state
 		struct {
 			bool interlaced = false, tall_characters = false;
-			uint8_t first_column_location, first_row_location;
-			uint8_t number_of_columns, number_of_rows;
-			uint16_t character_cell_start_address, video_matrix_start_address;
-			uint16_t backgroundColour, borderColour, auxiliary_colour;
+			uint8_t first_column_location = 0, first_row_location = 0;
+			uint8_t number_of_columns = 0, number_of_rows = 0;
+			uint16_t character_cell_start_address = 0, video_matrix_start_address = 0;
+			uint16_t backgroundColour = 0, borderColour = 0, auxiliary_colour = 0;
 			bool invertedCells = false;
 
-			uint8_t direct_values[16];
+			uint8_t direct_values[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 		} registers_;
 
 		// output state
 		enum State {
 			Sync, ColourBurst, Border, Pixels
-		} this_state_, output_state_;
-		int cycles_in_state_;
+		} this_state_ = State::Sync, output_state_ = State::Sync;
+		int cycles_in_state_ = 0;
 
 		// counters that cover an entire field
 		int horizontal_counter_ = 0, vertical_counter_ = 0;
-		const int lines_this_field() {
+		int lines_this_field() const {
 			// Necessary knowledge here: only the NTSC 6560 supports interlaced video.
 			return registers_.interlaced ? (is_odd_frame_ ? 262 : 263) : timing_.lines_per_progressive_field;
 		}
-		const int raster_value() {
+		int raster_value() const {
 			const int bonus_line = (horizontal_counter_ + timing_.line_counter_increment_offset) / timing_.cycles_per_line;
 			const int line = vertical_counter_ + bonus_line;
 			const int final_line = lines_this_field();
@@ -478,29 +481,29 @@ template <class BusHandler> class MOS6560 {
 			}
 			// Cf. http://www.sleepingelephant.com/ipw-web/bulletin/bb/viewtopic.php?f=14&t=7237&start=15#p80737
 		}
-		bool is_odd_frame() {
+		bool is_odd_frame() const {
 			return is_odd_frame_ || !registers_.interlaced;
 		}
 
 		// latches dictating start and length of drawing
 		bool vertical_drawing_latch_ = false, horizontal_drawing_latch_ = false;
-		int rows_this_field_, columns_this_line_;
+		int rows_this_field_ = 0, columns_this_line_ = 0;
 
 		// current drawing position counter
-		int pixel_line_cycle_, column_counter_;
-		int current_row_;
-		uint16_t current_character_row_;
-		uint16_t video_matrix_address_counter_, base_video_matrix_address_counter_;
+		int pixel_line_cycle_ = 0, column_counter_ = 0;
+		int current_row_ = 0;
+		uint16_t current_character_row_ = 0;
+		uint16_t video_matrix_address_counter_ = 0, base_video_matrix_address_counter_ = 0;
 
 		// data latched from the bus
-		uint8_t character_code_, character_colour_, character_value_;
+		uint8_t character_code_ = 0, character_colour_ = 0, character_value_ = 0;
 
 		bool is_odd_frame_ = false, is_odd_line_ = false;
 
 		// lookup table from 6560 colour index to appropriate PAL/NTSC value
-		uint16_t colours_[16];
+		uint16_t colours_[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 
-		uint16_t *pixel_pointer;
+		uint16_t *pixel_pointer = nullptr;
 		void output_border(int number_of_cycles) {
 			uint16_t *colour_pointer = reinterpret_cast<uint16_t *>(crt_.begin_data(1));
 			if(colour_pointer) *colour_pointer = registers_.borderColour;
@@ -508,13 +511,13 @@ template <class BusHandler> class MOS6560 {
 		}
 
 		struct {
-			int cycles_per_line;
-			int line_counter_increment_offset;
-			int final_line_increment_position;
-			int lines_per_progressive_field;
-			bool supports_interlacing;
+			int cycles_per_line = 0;
+			int line_counter_increment_offset = 0;
+			int final_line_increment_position = 0;
+			int lines_per_progressive_field = 0;
+			bool supports_interlacing = 0;
 		} timing_;
-		OutputMode output_mode_;
+		OutputMode output_mode_ = OutputMode::NTSC;
 };
 
 }

Components/6845/CRTC6845.hpp

@@ -111,7 +111,7 @@ template <class T> class CRTC6845 {
 		}
 
 		void run_for(Cycles cycles) {
-			int cyles_remaining = cycles.as_int();
+			auto cyles_remaining = cycles.as_integral();
 			while(cyles_remaining--) {
 				// check for end of visible characters
 				if(character_counter_ == registers_[1]) {
@@ -167,8 +167,8 @@ template <class T> class CRTC6845 {
 	private:
 		inline void perform_bus_cycle_phase1() {
 			// Skew theory of operation: keep a history of the last three states, and apply whichever is selected.
-			character_is_visible_shifter_ = (character_is_visible_shifter_ << 1) | static_cast<unsigned int>(character_is_visible_);
-			bus_state_.display_enable = (static_cast<int>(character_is_visible_shifter_) & display_skew_mask_) && line_is_visible_;
+			character_is_visible_shifter_ = (character_is_visible_shifter_ << 1) | unsigned(character_is_visible_);
+			bus_state_.display_enable = (int(character_is_visible_shifter_) & display_skew_mask_) && line_is_visible_;
 			bus_handler_.perform_bus_cycle_phase1(bus_state_);
 		}
 
@@ -240,7 +240,7 @@ template <class T> class CRTC6845 {
 		inline void do_end_of_frame() {
 			line_counter_ = 0;
 			line_is_visible_ = true;
-			line_address_ = static_cast<uint16_t>((registers_[12] << 8) | registers_[13]);
+			line_address_ = uint16_t((registers_[12] << 8) | registers_[13]);
 			bus_state_.refresh_address = line_address_;
 		}
 

Components/6850/6850.cpp

@@ -0,0 +1,228 @@
+//
+//  6850.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 10/10/2019.
+//  Copyright © 2019 Thomas Harte. All rights reserved.
+//
+
+#include "6850.hpp"
+
+#include <cassert>
+
+using namespace Motorola::ACIA;
+
+const HalfCycles ACIA::SameAsTransmit;
+
+ACIA::ACIA(HalfCycles transmit_clock_rate, HalfCycles receive_clock_rate) :
+	transmit_clock_rate_(transmit_clock_rate),
+	receive_clock_rate_((receive_clock_rate != SameAsTransmit) ? receive_clock_rate : transmit_clock_rate) {
+	transmit.set_writer_clock_rate(transmit_clock_rate);
+	request_to_send.set_writer_clock_rate(transmit_clock_rate);
+}
+
+uint8_t ACIA::read(int address) {
+	if(address&1) {
+		overran_ = false;
+		received_data_ |= NoValueMask;
+		update_interrupt_line();
+		return uint8_t(received_data_);
+	} else {
+		return get_status();
+	}
+}
+
+void ACIA::reset() {
+	transmit.reset_writing();
+	transmit.write(true);
+	request_to_send.reset_writing();
+
+	bits_received_ = bits_incoming_ = 0;
+	receive_interrupt_enabled_ = transmit_interrupt_enabled_ = false;
+	overran_ = false;
+	next_transmission_ = received_data_ = NoValueMask;
+
+	update_interrupt_line();
+	assert(!interrupt_line_);
+}
+
+void ACIA::write(int address, uint8_t value) {
+	if(address&1) {
+		next_transmission_ = value;
+		consider_transmission();
+		update_interrupt_line();
+	} else {
+		if((value&3) == 3) {
+			reset();
+		} else {
+			switch(value & 3) {
+				default:
+				case 0: divider_ = 1;	break;
+				case 1: divider_ = 16;	break;
+				case 2: divider_ = 64;	break;
+			}
+			switch((value >> 2) & 7) {
+				default:
+				case 0:	data_bits_ = 7; stop_bits_ = 2; parity_ = Parity::Even;	break;
+				case 1:	data_bits_ = 7; stop_bits_ = 2; parity_ = Parity::Odd;	break;
+				case 2:	data_bits_ = 7; stop_bits_ = 1; parity_ = Parity::Even;	break;
+				case 3:	data_bits_ = 7; stop_bits_ = 1; parity_ = Parity::Odd;	break;
+				case 4:	data_bits_ = 8; stop_bits_ = 2; parity_ = Parity::None;	break;
+				case 5:	data_bits_ = 8; stop_bits_ = 1; parity_ = Parity::None;	break;
+				case 6:	data_bits_ = 8; stop_bits_ = 1; parity_ = Parity::Even;	break;
+				case 7:	data_bits_ = 8; stop_bits_ = 1; parity_ = Parity::Odd;	break;
+			}
+			switch((value >> 5) & 3) {
+				case 0:	request_to_send.write(false); transmit_interrupt_enabled_ = false;	break;
+				case 1:	request_to_send.write(false); transmit_interrupt_enabled_ = true;	break;
+				case 2:	request_to_send.write(true); transmit_interrupt_enabled_ = false;	break;
+				case 3:
+					request_to_send.write(false);
+					transmit_interrupt_enabled_ = false;
+					transmit.reset_writing();
+					transmit.write(false);
+				break;
+			}
+			receive.set_read_delegate(this, Storage::Time(divider_ * 2, int(receive_clock_rate_.as_integral())));
+			receive_interrupt_enabled_ = value & 0x80;
+
+			update_interrupt_line();
+		}
+	}
+	update_clocking_observer();
+}
+
+void ACIA::consider_transmission() {
+	if(next_transmission_ != NoValueMask && !transmit.write_data_time_remaining()) {
+		// Establish start bit and [7 or 8] data bits.
+		if(data_bits_ == 7) next_transmission_ &= 0x7f;
+		int transmission = next_transmission_ << 1;
+
+		// Add a parity bit, if any.
+		int mask = 0x2 << data_bits_;
+		if(parity_ != Parity::None) {
+			transmission |= parity(uint8_t(next_transmission_)) ? mask : 0;
+			mask <<= 1;
+		}
+
+		// Add stop bits.
+		for(int c = 0; c < stop_bits_; ++c) {
+			transmission |= mask;
+			mask <<= 1;
+		}
+
+		// Output all that.
+		const int total_bits = expected_bits();
+		transmit.write(divider_ * 2, total_bits, transmission);
+
+		// Mark the transmit register as empty again.
+		next_transmission_ = NoValueMask;
+	}
+}
+
+ClockingHint::Preference ACIA::preferred_clocking() const {
+	// Real-time clocking is required if a transmission is ongoing; this is a courtesy for whomever
+	// is on the receiving end.
+	if(transmit.transmission_data_time_remaining() > 0) return ClockingHint::Preference::RealTime;
+
+	// If a bit reception is ongoing that might lead to an interrupt, ask for real-time clocking
+	// 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;
+}
+
+bool ACIA::get_interrupt_line() const {
+	return interrupt_line_;
+}
+
+int ACIA::expected_bits() {
+	return 1 + data_bits_ + stop_bits_ + (parity_ != Parity::None);
+}
+
+uint8_t ACIA::parity(uint8_t value) {
+	value ^= value >> 4;
+	value ^= value >> 2;
+	value ^= value >> 1;
+	return value ^ (parity_ == Parity::Even);
+}
+
+bool ACIA::serial_line_did_produce_bit(Serial::Line *, int bit) {
+	// Shift this bit into the 11-bit input register; this is big enough to hold
+	// the largest transmission symbol.
+	++bits_received_;
+	bits_incoming_ = (bits_incoming_ >> 1) | (bit << 10);
+
+	// If that's the now-expected number of bits, update.
+	const int bit_target = expected_bits();
+	if(bits_received_ >= bit_target) {
+		bits_received_ = 0;
+		overran_ |= get_status() & 1;
+		received_data_ = uint8_t(bits_incoming_ >> (12 - bit_target));
+		update_interrupt_line();
+		update_clocking_observer();
+		return false;
+	}
+
+	// TODO: overrun, and parity.
+
+	// Keep receiving, and consider a potential clocking change.
+	if(bits_received_ == 1) update_clocking_observer();
+	return true;
+}
+
+void ACIA::set_interrupt_delegate(InterruptDelegate *delegate) {
+	interrupt_delegate_ = delegate;
+}
+
+void ACIA::update_interrupt_line() {
+	const bool old_line = interrupt_line_;
+
+	/*
+		"Bit 7 of the control register is the rie bit. When the rie bit is high, the rdrf, ndcd,
+		and ovr bits will assert the nirq output. When the rie bit is low, nirq generation is disabled."
+
+		rie = read interrupt enable
+		rdrf = receive data register full (status word bit 0)
+		ndcd = data carrier detect (status word bit 2)
+		over = receiver overrun (status word bit 5)
+
+		"Bit 1 of the status register is the tdre bit. When high, the tdre bit indicates that data has been
+		transferred from the transmitter data register to the output shift register. At this point, the a6850
+		is ready to accept a new transmit data byte. However, if the ncts signal is high, the tdre bit remains
+		low regardless of the status of the transmitter data register. Also, if transmit interrupt is enabled,
+		the nirq output is asserted."
+
+		tdre = transmitter data register empty
+		ncts = clear to send
+	*/
+	const auto status = get_status();
+	interrupt_line_ =
+		(receive_interrupt_enabled_ && (status & 0x25)) ||
+		(transmit_interrupt_enabled_ && (status & 0x02));
+
+	if(interrupt_delegate_ && old_line != interrupt_line_) {
+		interrupt_delegate_->acia6850_did_change_interrupt_status(this);
+	}
+}
+
+uint8_t ACIA::get_status() {
+	return
+		((received_data_ & NoValueMask) ? 0x00 : 0x01) |
+		((next_transmission_ == NoValueMask) ? 0x02 : 0x00) |
+//		(data_carrier_detect.read() ? 0x04 : 0x00) |
+//		(clear_to_send.read() ? 0x08 : 0x00) |
+		(overran_ ? 0x20 : 0x00) |
+		(interrupt_line_ ? 0x80 : 0x00)
+	;
+
+	// b0: receive data full.
+	// b1: transmit data empty.
+	// b2: DCD.
+	// b3: CTS.
+	// b4: framing error (i.e. no first stop bit where expected).
+	// b5: receiver overran.
+	// b6: parity error.
+	// b7: IRQ state.
+}

Components/6850/6850.hpp

@@ -0,0 +1,132 @@
+//
+//  6850.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 10/10/2019.
+//  Copyright © 2019 Thomas Harte. All rights reserved.
+//
+
+#ifndef Motorola_ACIA_6850_hpp
+#define Motorola_ACIA_6850_hpp
+
+#include <cstdint>
+#include "../../ClockReceiver/ClockReceiver.hpp"
+#include "../../ClockReceiver/ForceInline.hpp"
+#include "../../ClockReceiver/ClockingHintSource.hpp"
+#include "../Serial/Line.hpp"
+
+namespace Motorola {
+namespace ACIA {
+
+class ACIA: public ClockingHint::Source, private Serial::Line::ReadDelegate {
+	public:
+		static constexpr const HalfCycles SameAsTransmit = HalfCycles(0);
+
+		/*!
+			Constructs a new instance of ACIA which will receive a transmission clock at a rate of
+			@c transmit_clock_rate, and a receive clock at a rate of @c receive_clock_rate.
+		*/
+		ACIA(HalfCycles transmit_clock_rate, HalfCycles receive_clock_rate = SameAsTransmit);
+
+		/*!
+			Reads from the ACIA.
+
+			Bit 0 of the address is used as the ACIA's register select line —
+			so even addresses select control/status registers, odd addresses
+			select transmit/receive data registers.
+		*/
+		uint8_t read(int address);
+
+		/*!
+			Writes to the ACIA.
+
+			Bit 0 of the address is used as the ACIA's register select line —
+			so even addresses select control/status registers, odd addresses
+			select transmit/receive data registers.
+		*/
+		void write(int address, uint8_t value);
+
+		/*!
+			Advances @c transmission_cycles in time, which should be
+			counted relative to the @c transmit_clock_rate.
+		*/
+		forceinline void run_for(HalfCycles transmission_cycles) {
+			if(transmit.transmission_data_time_remaining() > HalfCycles(0)) {
+				const auto write_data_time_remaining = transmit.write_data_time_remaining();
+
+				// There's at most one further byte available to enqueue, so a single 'if'
+				// rather than a 'while' is correct here. It's the responsibilit of the caller
+				// to ensure run_for lengths are appropriate for longer sequences.
+				if(transmission_cycles >= write_data_time_remaining) {
+					if(next_transmission_ != NoValueMask) {
+						transmit.advance_writer(write_data_time_remaining);
+						consider_transmission();
+						transmit.advance_writer(transmission_cycles - write_data_time_remaining);
+					} else {
+						transmit.advance_writer(transmission_cycles);
+						update_clocking_observer();
+						update_interrupt_line();
+					}
+				} else {
+					transmit.advance_writer(transmission_cycles);
+				}
+			}
+		}
+
+		bool get_interrupt_line() const;
+		void reset();
+
+		// Input lines.
+		Serial::Line receive;
+		Serial::Line clear_to_send;
+		Serial::Line data_carrier_detect;
+
+		// Output lines.
+		Serial::Line transmit;
+		Serial::Line request_to_send;
+
+		// ClockingHint::Source.
+		ClockingHint::Preference preferred_clocking() const final;
+
+		struct InterruptDelegate {
+			virtual void acia6850_did_change_interrupt_status(ACIA *acia) = 0;
+		};
+		void set_interrupt_delegate(InterruptDelegate *delegate);
+
+	private:
+		int divider_ = 1;
+		enum class Parity {
+			Even, Odd, None
+		} parity_ = Parity::None;
+		int data_bits_ = 7, stop_bits_ = 2;
+
+		static constexpr int NoValueMask = 0x100;
+		int next_transmission_ = NoValueMask;
+		int received_data_ = NoValueMask;
+
+		int bits_received_ = 0;
+		int bits_incoming_ = 0;
+		bool overran_ = false;
+
+		void consider_transmission();
+		int expected_bits();
+		uint8_t parity(uint8_t value);
+
+		bool receive_interrupt_enabled_ = false;
+		bool transmit_interrupt_enabled_ = false;
+
+		HalfCycles transmit_clock_rate_;
+		HalfCycles receive_clock_rate_;
+
+		bool serial_line_did_produce_bit(Serial::Line *line, int bit) final;
+
+		bool interrupt_line_ = false;
+		void update_interrupt_line();
+		InterruptDelegate *interrupt_delegate_ = nullptr;
+		uint8_t get_status();
+};
+
+}
+}
+
+#endif /* Motorola_ACIA_6850_hpp */

Components/68901/MFP68901.cpp

@@ -0,0 +1,374 @@
+//
+//  MFP68901.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 06/10/2019.
+//  Copyright © 2019 Thomas Harte. All rights reserved.
+//
+
+#include "MFP68901.hpp"
+
+#include <algorithm>
+#include <cstring>
+
+#ifndef NDEBUG
+#define NDEBUG
+#endif
+
+#define LOG_PREFIX "[MFP] "
+#include "../../Outputs/Log.hpp"
+
+using namespace Motorola::MFP68901;
+
+ClockingHint::Preference MFP68901::preferred_clocking() const {
+	// Rule applied: if any timer is actively running and permitted to produce an
+	// interrupt, request real-time running.
+	return
+		(timers_[0].mode >= TimerMode::Delay && interrupt_enable_&Interrupt::TimerA) ||
+		(timers_[1].mode >= TimerMode::Delay && interrupt_enable_&Interrupt::TimerB) ||
+		(timers_[2].mode >= TimerMode::Delay && interrupt_enable_&Interrupt::TimerC) ||
+		(timers_[3].mode >= TimerMode::Delay && interrupt_enable_&Interrupt::TimerD)
+			? ClockingHint::Preference::RealTime : ClockingHint::Preference::JustInTime;
+}
+
+uint8_t MFP68901::read(int address) {
+	address &= 0x1f;
+
+	// Interrupt block: various bits of state can be read, all passively.
+	if(address >= 0x03 && address <= 0x0b) {
+		const int shift = (address&1) << 3;
+		switch(address) {
+			case 0x03:	case 0x04:	return uint8_t(interrupt_enable_ >> shift);
+			case 0x05:	case 0x06:	return uint8_t(interrupt_pending_ >> shift);
+			case 0x07:	case 0x08:	return uint8_t(interrupt_in_service_ >> shift);
+			case 0x09:	case 0x0a:	return uint8_t(interrupt_mask_ >> shift);
+			case 0x0b:	return interrupt_vector_;
+
+			default: break;
+		}
+	}
+
+	switch(address) {
+		// GPIP block: input, and configured active edge and direction values.
+		case 0x00:	return (gpip_input_ & ~gpip_direction_) | (gpip_output_ & gpip_direction_);
+		case 0x01:	return gpip_active_edge_;
+		case 0x02:	return gpip_direction_;
+
+		/* Interrupt block dealt with above. */
+		default: break;
+
+		// Timer block: read back A, B and C/D control, and read current timer values.
+		case 0x0c:	case 0x0d:	return timer_ab_control_[address - 0xc];
+		case 0x0e:				return timer_cd_control_;
+		case 0x0f:	case 0x10:
+		case 0x11:	case 0x12:	return get_timer_data(address - 0xf);
+
+		// USART block: TODO.
+		case 0x13:		LOG("Read: sync character generator");	break;
+		case 0x14:		LOG("Read: USART control");				break;
+		case 0x15:		LOG("Read: receiver status");			break;
+		case 0x16:		LOG("Read: transmitter status");		break;
+		case 0x17:		LOG("Read: USART data");				break;
+	}
+	return 0x00;
+}
+
+void MFP68901::write(int address, uint8_t value) {
+	address &= 0x1f;
+
+	// Interrupt block: enabled and masked interrupts can be set; pending and in-service interrupts can be masked.
+	if(address >= 0x03 && address <= 0x0b) {
+		const int shift = (address&1) << 3;
+		const int preserve = 0xff00 >> shift;
+		const int word_value = value << shift;
+
+		switch(address) {
+			default: break;
+			case 0x03: case 0x04:	// Adjust enabled interrupts; disabled ones also cease to be pending.
+				interrupt_enable_ = (interrupt_enable_ & preserve) | word_value;
+				interrupt_pending_ &= interrupt_enable_;
+			break;
+			case 0x05: case 0x06:	// Resolve pending interrupts.
+				interrupt_pending_ &= (preserve | word_value);
+			break;
+			case 0x07: case 0x08:	// Resolve in-service interrupts.
+				interrupt_in_service_ &= (preserve | word_value);
+			break;
+			case 0x09: case 0x0a:	// Adjust interrupt mask.
+				interrupt_mask_ = (interrupt_mask_ & preserve) | word_value;
+			break;
+			case 0x0b:				// Set the interrupt vector, possibly changing end-of-interrupt mode.
+				interrupt_vector_ = value;
+
+				// If automatic end-of-interrupt mode has now been enabled, clear
+				// the in-process mask and re-evaluate.
+				if(interrupt_vector_ & 0x08) return;
+				interrupt_in_service_ = 0;
+			break;
+		}
+
+		// Whatever just happened may have affected the state of the interrupt line.
+		update_interrupts();
+		update_clocking_observer();
+		return;
+	}
+
+	constexpr int timer_prescales[] = {
+		1, 4, 10, 16, 50, 64, 100, 200
+	};
+
+	switch(address) {
+		// GPIP block: output and configuration of active edge and direction values.
+		case 0x00:
+			gpip_output_ = value;
+		break;
+		case 0x01:
+			gpip_active_edge_ = value;
+			reevaluate_gpip_interrupts();
+		break;
+		case 0x02:
+			gpip_direction_ = value;
+			reevaluate_gpip_interrupts();
+		break;
+
+		/* Interrupt block dealt with above. */
+		default: break;
+
+		// Timer block.
+		case 0x0c:
+		case 0x0d: {
+			const auto timer = address - 0xc;
+			const bool reset = value & 0x10;
+			timer_ab_control_[timer] = value;
+			switch(value & 0xf) {
+				case 0x0:	set_timer_mode(timer, TimerMode::Stopped, 1, reset);		break;
+				case 0x1:	set_timer_mode(timer, TimerMode::Delay, 4, reset);			break;
+				case 0x2:	set_timer_mode(timer, TimerMode::Delay, 10, reset);			break;
+				case 0x3:	set_timer_mode(timer, TimerMode::Delay, 16, reset);			break;
+				case 0x4:	set_timer_mode(timer, TimerMode::Delay, 50, reset);			break;
+				case 0x5:	set_timer_mode(timer, TimerMode::Delay, 64, reset);			break;
+				case 0x6:	set_timer_mode(timer, TimerMode::Delay, 100, reset);		break;
+				case 0x7:	set_timer_mode(timer, TimerMode::Delay, 200, reset);		break;
+				case 0x8:	set_timer_mode(timer, TimerMode::EventCount, 1, reset);		break;
+				case 0x9:	set_timer_mode(timer, TimerMode::PulseWidth, 4, reset);		break;
+				case 0xa:	set_timer_mode(timer, TimerMode::PulseWidth, 10, reset);	break;
+				case 0xb:	set_timer_mode(timer, TimerMode::PulseWidth, 16, reset);	break;
+				case 0xc:	set_timer_mode(timer, TimerMode::PulseWidth, 50, reset);	break;
+				case 0xd:	set_timer_mode(timer, TimerMode::PulseWidth, 64, reset);	break;
+				case 0xe:	set_timer_mode(timer, TimerMode::PulseWidth, 100, reset);	break;
+				case 0xf:	set_timer_mode(timer, TimerMode::PulseWidth, 200, reset);	break;
+			}
+		} break;
+		case 0x0e:
+			timer_cd_control_ = value;
+			set_timer_mode(3, (value & 7) ? TimerMode::Delay : TimerMode::Stopped, timer_prescales[value & 7], false);
+			set_timer_mode(2, ((value >> 4) & 7) ? TimerMode::Delay : TimerMode::Stopped, timer_prescales[(value >> 4) & 7], false);
+		break;
+		case 0x0f:	case 0x10:	case 0x11:	case 0x12:
+			set_timer_data(address - 0xf, value);
+		break;
+
+		// USART block: TODO.
+		case 0x13:		LOG("Write: sync character generator");	break;
+		case 0x14:		LOG("Write: USART control");			break;
+		case 0x15:		LOG("Write: receiver status");			break;
+		case 0x16:		LOG("Write: transmitter status");		break;
+		case 0x17:		LOG("Write: USART data");				break;
+	}
+
+	update_clocking_observer();
+}
+
+void MFP68901::run_for(HalfCycles time) {
+	cycles_left_ += time;
+
+	const int cycles = int(cycles_left_.flush<Cycles>().as_integral());
+	if(!cycles) return;
+
+	for(int c = 0; c < 4; ++c) {
+		if(timers_[c].mode >= TimerMode::Delay) {
+			// This code applies the timer prescaling only. prescale_count is used to count
+			// upwards rather than downwards for simplicity, but on the real hardware it's
+			// pretty safe to assume it actually counted downwards. So the clamp to 0 is
+			// because gymnastics may need to occur when the prescale value is altered, e.g.
+			// if a prescale of 256 is set and the prescale_count is currently 2 then the
+			// counter should roll over in 254 cycles. If the user at that point changes the
+			// prescale_count to 1 then the counter will need to be altered to -253 and
+			// allowed to keep counting up until it crosses both 0 and 1.
+			const int dividend = timers_[c].prescale_count + cycles;
+			const int decrements = std::max(dividend / timers_[c].prescale, 0);
+			if(decrements) {
+				decrement_timer(c, decrements);
+				timers_[c].prescale_count = dividend % timers_[c].prescale;
+			} else {
+				timers_[c].prescale_count += cycles;
+			}
+		}
+	}
+}
+
+HalfCycles MFP68901::get_next_sequence_point() {
+	return HalfCycles(-1);
+}
+
+// MARK: - Timers
+
+void MFP68901::set_timer_mode(int timer, TimerMode mode, int prescale, bool reset_timer) {
+	LOG("Timer " << timer << " mode set: " << int(mode) << "; prescale: " << prescale);
+	timers_[timer].mode = mode;
+	if(reset_timer) {
+		timers_[timer].prescale_count = 0;
+		timers_[timer].value = timers_[timer].reload_value;
+	} else {
+		// This hoop is because the prescale_count here goes upward but I'm assuming it goes downward in
+		// real hardware. Therefore this deals with the "switched to a lower prescaling" case whereby the
+		// old cycle should be allowed naturally to expire.
+		timers_[timer].prescale_count = prescale - (timers_[timer].prescale - timers_[timer].prescale_count);
+	}
+
+	timers_[timer].prescale = prescale;
+}
+
+void MFP68901::set_timer_data(int timer, uint8_t value) {
+	if(timers_[timer].mode == TimerMode::Stopped) {
+		timers_[timer].value = value;
+	}
+	timers_[timer].reload_value = value;
+}
+
+uint8_t MFP68901::get_timer_data(int timer) {
+	return timers_[timer].value;
+}
+
+void MFP68901::set_timer_event_input(int channel, bool value) {
+	if(timers_[channel].event_input == value) return;
+
+	timers_[channel].event_input = value;
+	if(timers_[channel].mode == TimerMode::EventCount && (value == !!(gpip_active_edge_ & (0x10 >> channel)))) {
+		// "The active state of the signal on TAI or TBI is dependent upon the associated
+		// Interrupt Channel’s edge bit (GPIP 4 for TAI and GPIP 3 for TBI [...] ).
+		// If the edge bit associated with the TAI or TBI input is a one, it will be active high.
+		decrement_timer(channel, 1);
+	}
+
+	// TODO:
+	//
+	// Altering the edge bit while the timer is in the event count mode can produce a count pulse.
+	// The interrupt channel associated with the input (I3 for I4 for TAI) is allowed to function normally.
+	// To count transitions reliably, the input must remain in each state (1/O) for a length of time equal
+	// to four periods of the timer clock.
+	//
+	// (the final bit probably explains 13 cycles of the DE to interrupt latency; not sure about the other ~15)
+}
+
+void MFP68901::decrement_timer(int timer, int amount) {
+	while(amount--) {
+		--timers_[timer].value;
+		if(timers_[timer].value < 1) {
+			switch(timer) {
+				case 0: begin_interrupts(Interrupt::TimerA);	break;
+				case 1: begin_interrupts(Interrupt::TimerB);	break;
+				case 2: begin_interrupts(Interrupt::TimerC);	break;
+				case 3: begin_interrupts(Interrupt::TimerD);	break;
+			}
+
+			// Re: reloading when in event counting mode; I found the data sheet thoroughly unclear on
+			// this, but it appears empirically to be correct. See e.g. Pompey Pirates menu 27.
+			if(timers_[timer].mode == TimerMode::Delay || timers_[timer].mode == TimerMode::EventCount) {
+				timers_[timer].value += timers_[timer].reload_value;	// TODO: properly.
+			}
+		}
+	}
+}
+
+// MARK: - GPIP
+void MFP68901::set_port_input(uint8_t input) {
+	gpip_input_ = input;
+	reevaluate_gpip_interrupts();
+}
+
+uint8_t MFP68901::get_port_output() {
+	return 0xff;	// TODO.
+}
+
+void MFP68901::reevaluate_gpip_interrupts() {
+	const uint8_t gpip_state = (gpip_input_ & ~gpip_direction_) ^ gpip_active_edge_;
+
+	// An interrupt is detected on any falling edge.
+	const uint8_t new_interrupt_mask = (gpip_state ^ gpip_interrupt_state_) & gpip_interrupt_state_;
+	if(new_interrupt_mask) {
+		begin_interrupts(
+			(new_interrupt_mask & 0x0f) |
+			((new_interrupt_mask & 0x30) << 2) |
+			((new_interrupt_mask & 0xc0) << 8)
+		);
+	}
+	gpip_interrupt_state_ = gpip_state;
+}
+
+// MARK: - Interrupts
+
+void MFP68901::begin_interrupts(int interrupt) {
+	interrupt_pending_ |= interrupt & interrupt_enable_;
+	update_interrupts();
+}
+
+void MFP68901::end_interrupts(int interrupt) {
+	interrupt_pending_ &= ~interrupt;
+	update_interrupts();
+}
+
+void MFP68901::update_interrupts() {
+	const auto old_interrupt_line = interrupt_line_;
+	const auto firing_interrupts = interrupt_pending_ & interrupt_mask_;
+
+	if(!firing_interrupts) {
+		interrupt_line_ = false;
+	} else {
+		if(interrupt_vector_ & 0x8) {
+			// Software interrupt mode: permit only if neither this interrupt
+			// nor a higher interrupt is currently in service.
+			const int highest_bit = msb16(firing_interrupts);
+			interrupt_line_ = !(interrupt_in_service_ & ~(highest_bit + highest_bit - 1));
+		} else {
+			// Auto-interrupt mode; just signal.
+			interrupt_line_ = true;
+		}
+	}
+
+	// Update the delegate if necessary.
+	if(interrupt_delegate_ && interrupt_line_ != old_interrupt_line) {
+		interrupt_delegate_->mfp68901_did_change_interrupt_status(this);
+	}
+}
+
+bool MFP68901::get_interrupt_line() {
+	return interrupt_line_;
+}
+
+int MFP68901::acknowledge_interrupt() {
+	if(!(interrupt_pending_ & interrupt_mask_)) {
+		return NoAcknowledgement;
+	}
+
+	const int mask = msb16(interrupt_pending_ & interrupt_mask_);
+
+	// Clear the pending bit regardless.
+	interrupt_pending_ &= ~mask;
+
+	// If this is software interrupt mode, set the in-service bit.
+	if(interrupt_vector_ & 0x8) {
+		interrupt_in_service_ |= mask;
+	}
+
+	update_interrupts();
+
+	int selected = 0;
+	while((1 << selected) != mask) ++selected;
+//	LOG("Interrupt acknowledged: " << selected);
+	return (interrupt_vector_ & 0xf0) | uint8_t(selected);
+}
+
+void MFP68901::set_interrupt_delegate(InterruptDelegate *delegate) {
+	interrupt_delegate_ = delegate;
+}

Components/68901/MFP68901.hpp

@@ -0,0 +1,187 @@
+//
+//  MFP68901.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 06/10/2019.
+//  Copyright © 2019 Thomas Harte. All rights reserved.
+//
+
+#ifndef MFP68901_hpp
+#define MFP68901_hpp
+
+#include <cstdint>
+#include "../../ClockReceiver/ClockReceiver.hpp"
+#include "../../ClockReceiver/ClockingHintSource.hpp"
+
+namespace Motorola {
+namespace MFP68901 {
+
+class PortHandler {
+	public:
+		// TODO: announce changes in output.
+};
+
+/*!
+	Models the Motorola 68901 Multi-Function Peripheral ('MFP').
+*/
+class MFP68901: public ClockingHint::Source {
+	public:
+		/// @returns the result of a read from @c address.
+		uint8_t read(int address);
+
+		/// Performs a write of @c value to @c address.
+		void write(int address, uint8_t value);
+
+		/// Advances the MFP by the supplied number of HalfCycles.
+		void run_for(HalfCycles);
+
+		/// @returns the number of cycles until the next possible sequence point — the next time
+		/// at which the interrupt line _might_ change. This object conforms to ClockingHint::Source
+		/// so that mechanism can also be used to reduce the quantity of calls into this class.
+		///
+		/// @discussion TODO, alas.
+		HalfCycles get_next_sequence_point();
+
+		/// Sets the current level of either of the timer event inputs — TAI and TBI in datasheet terms.
+		void set_timer_event_input(int channel, bool value);
+
+		/// Sets a port handler, a receiver that will be notified upon any change in GPIP output.
+		///
+		/// @discussion TODO.
+		void set_port_handler(PortHandler *);
+
+		/// Sets the current input GPIP values.
+		void set_port_input(uint8_t);
+
+		/// @returns the current GPIP output values.
+		///
+		/// @discussion TODO.
+		uint8_t get_port_output();
+
+		/// @returns @c true if the interrupt output is currently active; @c false otherwise.s
+		bool get_interrupt_line();
+
+		static constexpr int NoAcknowledgement = 0x100;
+
+		/// Communicates an interrupt acknowledge cycle.
+		///
+		/// @returns the vector placed on the bus if any; @c NoAcknowledgement if nothing is loaded.
+		int acknowledge_interrupt();
+
+		struct InterruptDelegate {
+			/// Informs the delegate of a change in the interrupt line of the nominated MFP.
+			virtual void mfp68901_did_change_interrupt_status(MFP68901 *) = 0;
+		};
+		/// Sets a delegate that will be notified upon any change in the interrupt line.
+		void set_interrupt_delegate(InterruptDelegate *delegate);
+
+		// ClockingHint::Source.
+		ClockingHint::Preference preferred_clocking() const final;
+
+	private:
+		// MARK: - Timers
+		enum class TimerMode {
+			Stopped, EventCount, Delay, PulseWidth
+		};
+		void set_timer_mode(int timer, TimerMode, int prescale, bool reset_timer);
+		void set_timer_data(int timer, uint8_t);
+		uint8_t get_timer_data(int timer);
+		void decrement_timer(int timer, int amount);
+
+		struct Timer {
+			TimerMode mode = TimerMode::Stopped;
+			uint8_t value = 0;
+			uint8_t reload_value = 0;
+			int prescale = 1;
+			int prescale_count = 1;
+			bool event_input = false;
+		} timers_[4];
+		uint8_t timer_ab_control_[2] = { 0, 0 };
+		uint8_t timer_cd_control_ = 0;
+
+		HalfCycles cycles_left_;
+
+		// MARK: - GPIP
+		uint8_t gpip_input_ = 0;
+		uint8_t gpip_output_ = 0;
+		uint8_t gpip_active_edge_ = 0;
+		uint8_t gpip_direction_ = 0;
+		uint8_t gpip_interrupt_state_ = 0;
+
+		void reevaluate_gpip_interrupts();
+
+		// MARK: - Interrupts
+
+		InterruptDelegate *interrupt_delegate_ = nullptr;
+
+		// Ad hoc documentation:
+		//
+		// An interrupt becomes pending if it is enabled at the time it occurs.
+		//
+		// If a pending interrupt is enabled in the interrupt mask, a processor
+		// interrupt is generated. Otherwise no processor interrupt is generated.
+		//
+		// (Disabling a bit in the enabled mask also instantaneously clears anything
+		// in the pending mask.)
+		//
+		// The user can write to the pending interrupt register; a write
+		// masks whatever is there — so you can disable bits but you cannot set them.
+		//
+		// If the vector register's 'S' bit is set then software end-of-interrupt mode applies:
+		// Acknowledgement of an interrupt clears that interrupt's pending bit, but also sets
+		// its in-service bit. That bit will remain set until the user writes a zero to its position.
+		// If any bits are set in the in-service register, then they will prevent lower-priority
+		// interrupts from being signalled to the CPU. Further interrupts of the same or a higher
+		// priority may occur.
+		//
+		// If the vector register's 'S' bit is clear then automatic end-of-interrupt mode applies:
+		// Acknowledgement of an interrupt will automatically clear the corresponding
+		// pending bit.
+		//
+		int interrupt_enable_ = 0;
+		int interrupt_pending_ = 0;
+		int interrupt_mask_ = 0;
+		int interrupt_in_service_ = 0;
+		bool interrupt_line_ = false;
+		uint8_t interrupt_vector_ = 0;
+
+		enum Interrupt {
+			GPIP0				= (1 << 0),
+			GPIP1				= (1 << 1),
+			GPIP2				= (1 << 2),
+			GPIP3				= (1 << 3),
+			TimerD				= (1 << 4),
+			TimerC				= (1 << 5),
+			GPIP4				= (1 << 6),
+			GPIP5				= (1 << 7),
+
+			TimerB				= (1 << 8),
+			TransmitError		= (1 << 9),
+			TransmitBufferEmpty	= (1 << 10),
+			ReceiveError		= (1 << 11),
+			ReceiveBufferFull	= (1 << 12),
+			TimerA				= (1 << 13),
+			GPIP6				= (1 << 14),
+			GPIP7				= (1 << 15),
+		};
+		void begin_interrupts(int interrupt);
+		void end_interrupts(int interrupt);
+		void update_interrupts();
+
+		/// @returns the most significant bit set in v, assuming it is one of the least significant 16.
+		inline static int msb16(int v) {
+			// Saturate all bits below the MSB.
+			v |= v >> 1;
+			v |= v >> 2;
+			v |= v >> 4;
+			v |= v >> 8;
+
+			// Throw away lesser bits.
+			return (v+1) >> 1;
+		}
+};
+
+}
+}
+
+#endif /* MFP68901_hpp */

Components/8255/i8255.hpp

@@ -9,13 +9,15 @@
 #ifndef i8255_hpp
 #define i8255_hpp
 
+#include <cstdint>
+
 namespace Intel {
 namespace i8255 {
 
 class PortHandler {
 	public:
-		void set_value(int port, uint8_t value) {}
-		uint8_t get_value(int port) { return 0xff; }
+		void set_value([[maybe_unused]] int port, [[maybe_unused]] uint8_t value) {}
+		uint8_t get_value([[maybe_unused]] int port) { return 0xff; }
 };
 
 // TODO: Modes 1 and 2.
@@ -27,7 +29,7 @@ template <class T> class i8255 {
 			Stores the value @c value to the register at @c address. If this causes a change in 8255 output
 			then the PortHandler will be informed.
 		*/
-		void set_register(int address, uint8_t value) {
+		void write(int address, uint8_t value) {
 			switch(address & 3) {
 				case 0:
 					if(!(control_ & 0x10)) {
@@ -60,7 +62,7 @@ template <class T> class i8255 {
 			Obtains the current value for the register at @c address. If this provides a reading
 			of input then the PortHandler will be queried.
 		*/
-		uint8_t get_register(int address) {
+		uint8_t read(int address) {
 			switch(address & 3) {
 				case 0:	return (control_ & 0x10) ? port_handler_.get_value(0) : outputs_[0];
 				case 1:	return (control_ & 0x02) ? port_handler_.get_value(1) : outputs_[1];

Components/8272/i8272.cpp

@@ -79,10 +79,14 @@ namespace {
 i8272::i8272(BusHandler &bus_handler, Cycles clock_rate) :
 	Storage::Disk::MFMController(clock_rate),
 	bus_handler_(bus_handler) {
-	posit_event(static_cast<int>(Event8272::CommandByte));
+	posit_event(int(Event8272::CommandByte));
+
+	// TODO: implement DMA, etc. I have a vague intention to implement the IBM PC
+	// one day, that should help to force that stuff.
+	(void)bus_handler_;
 }
 
-ClockingHint::Preference i8272::preferred_clocking() {
+ClockingHint::Preference i8272::preferred_clocking() const {
 	const auto mfm_controller_preferred_clocking = Storage::Disk::MFMController::preferred_clocking();
 	if(mfm_controller_preferred_clocking != ClockingHint::Preference::None) return mfm_controller_preferred_clocking;
 	return is_sleeping_ ? ClockingHint::Preference::None : ClockingHint::Preference::JustInTime;
@@ -95,11 +99,11 @@ void i8272::run_for(Cycles cycles) {
 
 	// check for an expired timer
 	if(delay_time_ > 0) {
-		if(cycles.as_int() >= delay_time_) {
+		if(cycles.as_integral() >= delay_time_) {
 			delay_time_ = 0;
-			posit_event(static_cast<int>(Event8272::Timer));
+			posit_event(int(Event8272::Timer));
 		} else {
-			delay_time_ -= cycles.as_int();
+			delay_time_ -= cycles.as_integral();
 		}
 	}
 
@@ -108,13 +112,13 @@ void i8272::run_for(Cycles cycles) {
 		int drives_left = drives_seeking_;
 		for(int c = 0; c < 4; c++) {
 			if(drives_[c].phase == Drive::Seeking) {
-				drives_[c].step_rate_counter += cycles.as_int();
-				int steps = drives_[c].step_rate_counter / (8000 * step_rate_time_);
+				drives_[c].step_rate_counter += cycles.as_integral();
+				auto steps = drives_[c].step_rate_counter / (8000 * step_rate_time_);
 				drives_[c].step_rate_counter %= (8000 * step_rate_time_);
 				while(steps--) {
 					// Perform a step.
 					int direction = (drives_[c].target_head_position < drives_[c].head_position) ? -1 : 1;
-					LOG("Target " << PADDEC(0) << drives_[c].target_head_position << " versus believed " << static_cast<int>(drives_[c].head_position));
+					LOG("Target " << PADDEC(0) << drives_[c].target_head_position << " versus believed " << int(drives_[c].head_position));
 					select_drive(c);
 					get_drive().step(Storage::Disk::HeadPosition(direction));
 					if(drives_[c].target_head_position >= 0) drives_[c].head_position += direction;
@@ -141,12 +145,12 @@ void i8272::run_for(Cycles cycles) {
 			int head = c&1;
 
 			if(drives_[drive].head_unload_delay[head] > 0) {
-				if(cycles.as_int() >= drives_[drive].head_unload_delay[head]) {
+				if(cycles.as_integral() >= drives_[drive].head_unload_delay[head]) {
 					drives_[drive].head_unload_delay[head] = 0;
 					drives_[drive].head_is_loaded[head] = false;
 					head_timers_running_--;
 				} else {
-					drives_[drive].head_unload_delay[head] -= cycles.as_int();
+					drives_[drive].head_unload_delay[head] -= cycles.as_integral();
 				}
 				timers_left--;
 				if(!timers_left) break;
@@ -156,14 +160,14 @@ void i8272::run_for(Cycles cycles) {
 
 	// check for busy plus ready disabled
 	if(is_executing_ && !get_drive().get_is_ready()) {
-		posit_event(static_cast<int>(Event8272::NoLongerReady));
+		posit_event(int(Event8272::NoLongerReady));
 	}
 
 	is_sleeping_ = !delay_time_ && !drives_seeking_ && !head_timers_running_;
 	if(is_sleeping_) update_clocking_observer();
 }
 
-void i8272::set_register(int address, uint8_t value) {
+void i8272::write(int address, uint8_t value) {
 	// don't consider attempted sets to the status register
 	if(!address) return;
 
@@ -177,16 +181,16 @@ void i8272::set_register(int address, uint8_t value) {
 	} else {
 		// accumulate latest byte in the command byte sequence
 		command_.push_back(value);
-		posit_event(static_cast<int>(Event8272::CommandByte));
+		posit_event(int(Event8272::CommandByte));
 	}
 }
 
-uint8_t i8272::get_register(int address) {
+uint8_t i8272::read(int address) {
 	if(address) {
 		if(result_stack_.empty()) return 0xff;
 		uint8_t result = result_stack_.back();
 		result_stack_.pop_back();
-		if(result_stack_.empty()) posit_event(static_cast<int>(Event8272::ResultEmpty));
+		if(result_stack_.empty()) posit_event(int(Event8272::ResultEmpty));
 
 		return result;
 	} else {
@@ -198,16 +202,16 @@ uint8_t i8272::get_register(int address) {
 #define END_SECTION()	}
 
 #define MS_TO_CYCLES(x)			x * 8000
-#define WAIT_FOR_EVENT(mask)	resume_point_ = __LINE__; interesting_event_mask_ = static_cast<int>(mask); return; case __LINE__:
-#define WAIT_FOR_TIME(ms)		resume_point_ = __LINE__; interesting_event_mask_ = static_cast<int>(Event8272::Timer); delay_time_ = MS_TO_CYCLES(ms); is_sleeping_ = false; update_clocking_observer(); case __LINE__: if(delay_time_) return;
+#define WAIT_FOR_EVENT(mask)	resume_point_ = __LINE__; interesting_event_mask_ = int(mask); return; case __LINE__:
+#define WAIT_FOR_TIME(ms)		resume_point_ = __LINE__; interesting_event_mask_ = int(Event8272::Timer); delay_time_ = MS_TO_CYCLES(ms); is_sleeping_ = false; update_clocking_observer(); case __LINE__: if(delay_time_) return;
 
 #define PASTE(x, y) x##y
 #define CONCAT(x, y) PASTE(x, y)
 
 #define FIND_HEADER()	\
 	set_data_mode(DataMode::Scanning);	\
-	CONCAT(find_header, __LINE__): WAIT_FOR_EVENT(static_cast<int>(Event::Token) | static_cast<int>(Event::IndexHole)); \
-	if(event_type == static_cast<int>(Event::IndexHole)) { index_hole_limit_--; }	\
+	CONCAT(find_header, __LINE__): WAIT_FOR_EVENT(int(Event::Token) | int(Event::IndexHole)); \
+	if(event_type == int(Event::IndexHole)) { index_hole_limit_--; }	\
 	else if(get_latest_token().type == Token::ID) goto CONCAT(header_found, __LINE__);	\
 	\
 	if(index_hole_limit_) goto CONCAT(find_header, __LINE__);	\
@@ -215,8 +219,8 @@ uint8_t i8272::get_register(int address) {
 
 #define FIND_DATA()	\
 	set_data_mode(DataMode::Scanning);	\
-	CONCAT(find_data, __LINE__): WAIT_FOR_EVENT(static_cast<int>(Event::Token) | static_cast<int>(Event::IndexHole)); \
-	if(event_type == static_cast<int>(Event::Token)) { \
+	CONCAT(find_data, __LINE__): WAIT_FOR_EVENT(int(Event::Token) | int(Event::IndexHole)); \
+	if(event_type == int(Event::Token)) { \
 		if(get_latest_token().type == Token::Byte || get_latest_token().type == Token::Sync) goto CONCAT(find_data, __LINE__);	\
 	}
 
@@ -264,8 +268,8 @@ uint8_t i8272::get_register(int address) {
 	}
 
 void i8272::posit_event(int event_type) {
-	if(event_type == static_cast<int>(Event::IndexHole)) index_hole_count_++;
-	if(event_type == static_cast<int>(Event8272::NoLongerReady)) {
+	if(event_type == int(Event::IndexHole)) index_hole_count_++;
+	if(event_type == int(Event8272::NoLongerReady)) {
 		SetNotReady();
 		goto abort;
 	}
@@ -292,7 +296,7 @@ void i8272::posit_event(int event_type) {
 			WAIT_FOR_EVENT(Event8272::CommandByte)
 			SetBusy();
 
-			static const std::size_t required_lengths[32] = {
+			static constexpr std::size_t required_lengths[32] = {
 				0,	0,	9,	3,	2,	9,	9,	2,
 				1,	9,	2,	0,	9,	6,	0,	3,
 				0,	9,	0,	0,	0,	0,	0,	0,
@@ -425,12 +429,12 @@ void i8272::posit_event(int event_type) {
 	// Performs the read data or read deleted data command.
 	read_data:
 			LOG(PADHEX(2) << "Read [deleted] data ["
-				<< static_cast<int>(command_[2]) << " "
-				<< static_cast<int>(command_[3]) << " "
-				<< static_cast<int>(command_[4]) << " "
-				<< static_cast<int>(command_[5]) << " ... "
-				<< static_cast<int>(command_[6]) << " "
-				<< static_cast<int>(command_[8]) << "]");
+				<< int(command_[2]) << " "
+				<< int(command_[3]) << " "
+				<< int(command_[4]) << " "
+				<< int(command_[5]) << " ... "
+				<< int(command_[6]) << " "
+				<< int(command_[8]) << "]");
 		read_next_data:
 			goto read_write_find_header;
 
@@ -439,7 +443,7 @@ void i8272::posit_event(int event_type) {
 		read_data_found_header:
 			FIND_DATA();
 			ClearControlMark();
-			if(event_type == static_cast<int>(Event::Token)) {
+			if(event_type == int(Event::Token)) {
 				if(get_latest_token().type != Token::Data && get_latest_token().type != Token::DeletedData) {
 					// Something other than a data mark came next, impliedly an ID or index mark.
 					SetMissingAddressMark();
@@ -470,24 +474,24 @@ void i8272::posit_event(int event_type) {
 		//
 		// TODO: consider DTL.
 		read_data_get_byte:
-			WAIT_FOR_EVENT(static_cast<int>(Event::Token) | static_cast<int>(Event::IndexHole));
-			if(event_type == static_cast<int>(Event::Token)) {
+			WAIT_FOR_EVENT(int(Event::Token) | int(Event::IndexHole));
+			if(event_type == int(Event::Token)) {
 				result_stack_.push_back(get_latest_token().byte_value);
 				distance_into_section_++;
 				SetDataRequest();
 				SetDataDirectionToProcessor();
-				WAIT_FOR_EVENT(static_cast<int>(Event8272::ResultEmpty) | static_cast<int>(Event::Token) | static_cast<int>(Event::IndexHole));
+				WAIT_FOR_EVENT(int(Event8272::ResultEmpty) | int(Event::Token) | int(Event::IndexHole));
 			}
 			switch(event_type) {
-				case static_cast<int>(Event8272::ResultEmpty):	// The caller read the byte in time; proceed as normal.
+				case int(Event8272::ResultEmpty):	// The caller read the byte in time; proceed as normal.
 					ResetDataRequest();
 					if(distance_into_section_ < (128 << size_)) goto read_data_get_byte;
 				break;
-				case static_cast<int>(Event::Token):				// The caller hasn't read the old byte yet and a new one has arrived
+				case int(Event::Token):				// The caller hasn't read the old byte yet and a new one has arrived
 					SetOverrun();
 					goto abort;
 				break;
-				case static_cast<int>(Event::IndexHole):
+				case int(Event::IndexHole):
 					SetEndOfCylinder();
 					goto abort;
 				break;
@@ -515,12 +519,12 @@ void i8272::posit_event(int event_type) {
 
 	write_data:
 			LOG(PADHEX(2) << "Write [deleted] data ["
-				<< static_cast<int>(command_[2]) << " "
-				<< static_cast<int>(command_[3]) << " "
-				<< static_cast<int>(command_[4]) << " "
-				<< static_cast<int>(command_[5]) << " ... "
-				<< static_cast<int>(command_[6]) << " "
-				<< static_cast<int>(command_[8]) << "]");
+				<< int(command_[2]) << " "
+				<< int(command_[3]) << " "
+				<< int(command_[4]) << " "
+				<< int(command_[5]) << " ... "
+				<< int(command_[6]) << " "
+				<< int(command_[8]) << "]");
 
 			if(get_drive().get_is_read_only()) {
 				SetNotWriteable();
@@ -571,7 +575,7 @@ void i8272::posit_event(int event_type) {
 	// Performs the read ID command.
 	read_id:
 		// Establishes the drive and head being addressed, and whether in double density mode.
-			LOG(PADHEX(2) << "Read ID [" << static_cast<int>(command_[0]) << " " << static_cast<int>(command_[1]) << "]");
+			LOG(PADHEX(2) << "Read ID [" << int(command_[0]) << " " << int(command_[1]) << "]");
 
 		// Sets a maximum index hole limit of 2 then waits either until it finds a header mark or sees too many index holes.
 		// If a header mark is found, reads in the following bytes that produce a header. Otherwise branches to data not found.
@@ -594,10 +598,10 @@ void i8272::posit_event(int event_type) {
 	// Performs read track.
 	read_track:
 			LOG(PADHEX(2) << "Read track ["
-				<< static_cast<int>(command_[2]) << " "
-				<< static_cast<int>(command_[3]) << " "
-				<< static_cast<int>(command_[4]) << " "
-				<< static_cast<int>(command_[5]) << "]");
+				<< int(command_[2]) << " "
+				<< int(command_[3]) << " "
+				<< int(command_[4]) << " "
+				<< int(command_[5]) << "]");
 
 			// Wait for the index hole.
 			WAIT_FOR_EVENT(Event::IndexHole);
@@ -627,7 +631,7 @@ void i8272::posit_event(int event_type) {
 			distance_into_section_++;
 			SetDataRequest();
 			// TODO: other possible exit conditions; find a way to merge with the read_data version of this.
-			WAIT_FOR_EVENT(static_cast<int>(Event8272::ResultEmpty));
+			WAIT_FOR_EVENT(int(Event8272::ResultEmpty));
 			ResetDataRequest();
 			if(distance_into_section_ < (128 << header_[2])) goto read_track_get_byte;
 
@@ -664,13 +668,13 @@ void i8272::posit_event(int event_type) {
 			expects_input_ = true;
 			distance_into_section_ = 0;
 		format_track_write_header:
-			WAIT_FOR_EVENT(static_cast<int>(Event::DataWritten) | static_cast<int>(Event::IndexHole));
+			WAIT_FOR_EVENT(int(Event::DataWritten) | int(Event::IndexHole));
 			switch(event_type) {
-				case static_cast<int>(Event::IndexHole):
+				case int(Event::IndexHole):
 					SetOverrun();
 					goto abort;
 				break;
-				case static_cast<int>(Event::DataWritten):
+				case int(Event::DataWritten):
 					header_[distance_into_section_] = input_;
 					write_byte(input_);
 					has_input_ = false;
@@ -683,10 +687,10 @@ void i8272::posit_event(int event_type) {
 			}
 
 			LOG(PADHEX(2) << "W:"
-				<< static_cast<int>(header_[0]) << " "
-				<< static_cast<int>(header_[1]) << " "
-				<< static_cast<int>(header_[2]) << " "
-				<< static_cast<int>(header_[3]) << ", "
+				<< int(header_[0]) << " "
+				<< int(header_[1]) << " "
+				<< int(header_[2]) << " "
+				<< int(header_[3]) << ", "
 				<< get_crc_generator().get_value());
 			write_crc();
 
@@ -706,8 +710,8 @@ void i8272::posit_event(int event_type) {
 			// Otherwise, pad out to the index hole.
 		format_track_pad:
 			write_byte(get_is_double_density() ? 0x4e : 0xff);
-			WAIT_FOR_EVENT(static_cast<int>(Event::DataWritten) | static_cast<int>(Event::IndexHole));
-			if(event_type != static_cast<int>(Event::IndexHole)) goto format_track_pad;
+			WAIT_FOR_EVENT(int(Event::DataWritten) | int(Event::IndexHole));
+			if(event_type != int(Event::IndexHole)) goto format_track_pad;
 
 			end_writing();
 
@@ -758,7 +762,7 @@ void i8272::posit_event(int event_type) {
 				// up in run_for understands to mean 'keep going until track 0 is active').
 				if(command_.size() > 2) {
 					drives_[drive].target_head_position = command_[2];
-					LOG(PADHEX(2) << "Seek to " << static_cast<int>(command_[2]));
+					LOG(PADHEX(2) << "Seek to " << int(command_[2]));
 				} else {
 					drives_[drive].target_head_position = -1;
 					drives_[drive].head_position = 0;
@@ -789,7 +793,7 @@ void i8272::posit_event(int event_type) {
 				// If a drive was found, return its results. Otherwise return a single 0x80.
 				if(found_drive != -1) {
 					drives_[found_drive].phase = Drive::NotSeeking;
-					status_[0] = static_cast<uint8_t>(found_drive);
+					status_[0] = uint8_t(found_drive);
 					main_status_ &= ~(1 << found_drive);
 					SetSeekEnd();
 
@@ -819,7 +823,7 @@ void i8272::posit_event(int event_type) {
 				int drive = command_[1] & 3;
 				select_drive(drive);
 				result_stack_= {
-					static_cast<uint8_t>(
+					uint8_t(
 						(command_[1] & 7) |	// drive and head number
 						0x08 |				// single sided
 						(get_drive().get_is_track_zero() ? 0x10 : 0x00)	|
@@ -853,9 +857,9 @@ void i8272::posit_event(int event_type) {
 	// Posts whatever is in result_stack_ as a result phase. Be aware that it is a stack, so the
 	// last thing in it will be returned first.
 	post_result:
-			LOGNBR(PADHEX(2) << "Result to " << static_cast<int>(command_[0] & 0x1f) << ", main " << static_cast<int>(main_status_) << "; ");
+			LOGNBR(PADHEX(2) << "Result to " << int(command_[0] & 0x1f) << ", main " << int(main_status_) << "; ");
 			for(std::size_t c = 0; c < result_stack_.size(); c++) {
-				LOGNBR(" " << static_cast<int>(result_stack_[result_stack_.size() - 1 - c]));
+				LOGNBR(" " << int(result_stack_[result_stack_.size() - 1 - c]));
 			}
 			LOGNBR(std::endl);
 
@@ -865,7 +869,7 @@ void i8272::posit_event(int event_type) {
 			SetDataRequest();
 			SetDataDirectionToProcessor();
 
-			// The actual stuff of unwinding result_stack_ is handled by ::get_register; wait
+			// The actual stuff of unwinding result_stack_ is handled by ::read; wait
 			// until the processor has read all result bytes.
 			WAIT_FOR_EVENT(Event8272::ResultEmpty);
 
@@ -880,13 +884,13 @@ bool i8272::seek_is_satisfied(int drive) {
 			(drives_[drive].target_head_position == -1 && get_drive().get_is_track_zero());
 }
 
-void i8272::set_dma_acknowledge(bool dack) {
+void i8272::set_dma_acknowledge(bool) {
 }
 
-void i8272::set_terminal_count(bool tc) {
+void i8272::set_terminal_count(bool) {
 }
 
-void i8272::set_data_input(uint8_t value) {
+void i8272::set_data_input(uint8_t) {
 }
 
 uint8_t i8272::get_data_output() {

Components/8272/i8272.hpp

@@ -20,11 +20,12 @@ namespace i8272 {
 
 class BusHandler {
 	public:
-		virtual void set_dma_data_request(bool drq) {}
-		virtual void set_interrupt(bool irq) {}
+		virtual ~BusHandler() {}
+		virtual void set_dma_data_request([[maybe_unused]] bool drq) {}
+		virtual void set_interrupt([[maybe_unused]] bool irq) {}
 };
 
-class i8272: public Storage::Disk::MFMController {
+class i8272 : public Storage::Disk::MFMController {
 	public:
 		i8272(BusHandler &bus_handler, Cycles clock_rate);
 
@@ -33,19 +34,19 @@ class i8272: public Storage::Disk::MFMController {
 		void set_data_input(uint8_t value);
 		uint8_t get_data_output();
 
-		void set_register(int address, uint8_t value);
-		uint8_t get_register(int address);
+		void write(int address, uint8_t value);
+		uint8_t read(int address);
 
 		void set_dma_acknowledge(bool dack);
 		void set_terminal_count(bool tc);
 
-		ClockingHint::Preference preferred_clocking() override;
+		ClockingHint::Preference preferred_clocking() const final;
 
 	protected:
 		virtual void select_drive(int number) = 0;
 
 	private:
-		// The bus handler, for interrupt and DMA-driven usage.
+		// The bus handler, for interrupt and DMA-driven usage. [TODO]
 		BusHandler &bus_handler_;
 		std::unique_ptr<BusHandler> allocated_bus_handler_;
 
@@ -67,13 +68,13 @@ class i8272: public Storage::Disk::MFMController {
 			ResultEmpty = (1 << 5),
 			NoLongerReady = (1 << 6)
 		};
-		void posit_event(int type) override;
-		int interesting_event_mask_ = static_cast<int>(Event8272::CommandByte);
+		void posit_event(int type) final;
+		int interesting_event_mask_ = int(Event8272::CommandByte);
 		int resume_point_ = 0;
 		bool is_access_command_ = false;
 
 		// The counter used for ::Timer events.
-		int delay_time_ = 0;
+		Cycles::IntType delay_time_ = 0;
 
 		// The connected drives.
 		struct Drive {
@@ -89,12 +90,12 @@ class i8272: public Storage::Disk::MFMController {
 			bool seek_failed = false;
 
 			// Seeking: transient state.
-			int step_rate_counter = 0;
+			Cycles::IntType step_rate_counter = 0;
 			int steps_taken = 0;
 			int target_head_position = 0;	// either an actual number, or -1 to indicate to step until track zero
 
 			// Head state.
-			int head_unload_delay[2] = {0, 0};
+			Cycles::IntType head_unload_delay[2] = {0, 0};
 			bool head_is_loaded[2] = {false, false};
 
 		} drives_[4];

Components/8530/z8530.cpp

@@ -8,6 +8,7 @@
 
 #include "z8530.hpp"
 
+#define LOG_PREFIX "[SCC] "
 #include "../../Outputs/Log.hpp"
 
 using namespace Zilog::SCC;
@@ -16,7 +17,7 @@ void z8530::reset() {
 	// TODO.
 }
 
-bool z8530::get_interrupt_line() {
+bool z8530::get_interrupt_line() const {
 	return
 		(master_interrupt_control_ & 0x8) &&
 		(
@@ -25,22 +26,30 @@ bool z8530::get_interrupt_line() {
 		);
 }
 
+/*
+	Per the standard defined in the header file, this implementation follows
+	an addressing convention of:
+
+	A0 = A/B		(i.e. channel select)
+	A1 = C/D		(i.e. control or data)
+*/
+
 std::uint8_t z8530::read(int address) {
 	if(address & 2) {
-		// Read data register for channel
-		return 0x00;
+		// Read data register for channel.
+		return channels_[address & 1].read(true, pointer_);
 	} else {
 		// Read control register for channel.
 		uint8_t result = 0;
 
 		switch(pointer_) {
 			default:
-				result = channels_[address & 1].read(address & 2, pointer_);
+				result = channels_[address & 1].read(false, pointer_);
 			break;
 
 			case 2:		// Handled non-symmetrically between channels.
 				if(address & 1) {
-					LOG("[SCC] Unimplemented: register 2 status bits");
+					LOG("Unimplemented: register 2 status bits");
 				} else {
 					result = interrupt_vector_;
 
@@ -63,7 +72,11 @@ std::uint8_t z8530::read(int address) {
 			break;
 		}
 
+		// Cf. the two-step control register selection process in ::write. Since this
+		// definitely wasn't a *write* to register 0, it follows that the next selected
+		// control register will be 0.
 		pointer_ = 0;
+
 		update_delegate();
 		return result;
 	}
@@ -73,24 +86,31 @@ std::uint8_t z8530::read(int address) {
 
 void z8530::write(int address, std::uint8_t value) {
 	if(address & 2) {
-		// Write data register for channel.
+		// Write data register for channel. This is completely independent
+		// of whatever is going on over in the control realm.
+		channels_[address & 1].write(true, pointer_, value);
 	} else {
-		// Write control register for channel.
+		// Write control register for channel; there's a two-step sequence
+		// here for the programmer. Initially the selected register
+		// (i.e. `pointer_`) is zero. That register includes a field to
+		// set the next selected register. After any other register has
+		// been written to, register 0 is selected again.
 
-		// Most registers are per channel, but a couple are shared; sever
-		// them here.
+		// Most registers are per channel, but a couple are shared;
+		// sever them here, send the rest to the appropriate chnanel.
 		switch(pointer_) {
 			default:
-				channels_[address & 1].write(address & 2, pointer_, value);
+				channels_[address & 1].write(false, pointer_, value);
 			break;
 
-			case 2:	// Interrupt vector register; shared between both channels.
+			case 2:	// Interrupt vector register; used only by Channel B.
+					// So there's only one of these.
 				interrupt_vector_ = value;
-				LOG("[SCC] Interrupt vector set to " << PADHEX(2) << int(value));
+				LOG("Interrupt vector set to " << PADHEX(2) << int(value));
 			break;
 
-			case 9:	// Master interrupt and reset register; also shared between both channels.
-				LOG("[SCC] Master interrupt and reset register: " << PADHEX(2) << int(value));
+			case 9:	// Master interrupt and reset register; there is also only one of these.
+				LOG("Master interrupt and reset register: " << PADHEX(2) << int(value));
 				master_interrupt_control_ = value;
 			break;
 		}
@@ -105,7 +125,8 @@ void z8530::write(int address, std::uint8_t value) {
 			pointer_ = value & 7;
 
 			// If the command part of the byte is a 'point high', also set the
-			// top bit of the pointer.
+			// top bit of the pointer. Channels themselves therefore need not
+			// (/should not) respond to the point high command.
 			if(((value >> 3)&7) == 1) {
 				pointer_ |= 8;
 			}
@@ -126,16 +147,79 @@ uint8_t z8530::Channel::read(bool data, uint8_t pointer) {
 	if(data) {
 		return data_;
 	} else {
+		LOG("Control read from register " << int(pointer));
 		// Otherwise, this is a control read...
 		switch(pointer) {
 			default:
-				LOG("[SCC] Unrecognised control read from register " << int(pointer));
 			return 0x00;
 
-			case 0:
+			case 0x0:	// Read Register 0; see p.37 (PDF p.45).
+				// b0: Rx character available.
+				// b1: zero count.
+				// b2: Tx buffer empty.
+				// b3: DCD.
+				// b4: sync/hunt.
+				// b5: CTS.
+				// b6: Tx underrun/EOM.
+				// b7: break/abort.
 			return dcd_ ? 0x8 : 0x0;
 
-			case 0xf:
+			case 0x1:	// Read Register 1; see p.37 (PDF p.45).
+				// b0: all sent.
+				// b1: residue code 0.
+				// b2: residue code 1.
+				// b3: residue code 2.
+				// b4: parity error.
+				// b5: Rx overrun error.
+				// b6: CRC/framing error.
+				// b7: end of frame (SDLC).
+			return 0x01;
+
+			case 0x2:	// Read Register 2; see p.37 (PDF p.45).
+				// Interrupt vector — modified by status information in B channel.
+			return 0x00;
+
+			case 0x3:	// Read Register 3; see p.37 (PDF p.45).
+				// B channel: all bits are 0.
+				// A channel:
+				// b0: Channel B ext/status IP.
+				// b1: Channel B Tx IP.
+				// b2: Channel B Rx IP.
+				// b3: Channel A ext/status IP.
+				// b4: Channel A Tx IP.
+				// b5: Channel A Rx IP.
+				// b6, b7: 0.
+			return 0x00;
+
+			case 0xa:	// Read Register 10; see p.37 (PDF p.45).
+				// b0: 0
+				// b1: On loop.
+				// b2: 0
+				// b3: 0
+				// b4: Loop sending.
+				// b5: 0
+				// b6: Two clocks missing.
+				// b7: One clock missing.
+			return 0x00;
+
+			case 0xc:	// Read Register 12; see p.37 (PDF p.45).
+				// Lower byte of time constant.
+			return 0x00;
+
+			case 0xd:	// Read Register 13; see p.38 (PDF p.46).
+				// Upper byte of time constant.
+			return 0x00;
+
+			case 0xf:	// Read Register 15; see p.38 (PDF p.46).
+				// External interrupt status:
+				// b0: 0
+				// b1: Zero count.
+				// b2: 0
+				// b3: DCD.
+				// b4: Sync/hunt.
+				// b5: CTS.
+				// b6: Tx underrun/EOM.
+				// b7: Break/abort.
 			return external_interrupt_status_;
 		}
 	}
@@ -148,9 +232,10 @@ void z8530::Channel::write(bool data, uint8_t pointer, uint8_t value) {
 		data_ = value;
 		return;
 	} else {
+		LOG("Control write: " << PADHEX(2) << int(value) << " to register " << int(pointer));
 		switch(pointer) {
 			default:
-				LOG("[SCC] Unrecognised control write: " << PADHEX(2) << int(value) << " to register " << int(pointer));
+				LOG("Unrecognised control write: " << PADHEX(2) << int(value) << " to register " << int(pointer));
 			break;
 
 			case 0x0:	// Write register 0 — CRC reset and other functions.
@@ -158,13 +243,13 @@ void z8530::Channel::write(bool data, uint8_t pointer, uint8_t value) {
 				switch(value >> 6) {
 					default:	/* Do nothing. */		break;
 					case 1:
-						LOG("[SCC] TODO: reset Rx CRC checker.");
+						LOG("TODO: reset Rx CRC checker.");
 					break;
 					case 2:
-						LOG("[SCC] TODO: reset Tx CRC checker.");
+						LOG("TODO: reset Tx CRC checker.");
 					break;
 					case 3:
-						LOG("[SCC] TODO: reset Tx underrun/EOM latch.");
+						LOG("TODO: reset Tx underrun/EOM latch.");
 					break;
 				}
 
@@ -172,32 +257,84 @@ void z8530::Channel::write(bool data, uint8_t pointer, uint8_t value) {
 				switch((value >> 3)&7) {
 					default:	/* Do nothing. */		break;
 					case 2:
-//						LOG("[SCC] reset ext/status interrupts.");
+//						LOG("reset ext/status interrupts.");
 						external_status_interrupt_ = false;
 						external_interrupt_status_ = 0;
 					break;
 					case 3:
-						LOG("[SCC] TODO: send abort (SDLC).");
+						LOG("TODO: send abort (SDLC).");
 					break;
 					case 4:
-						LOG("[SCC] TODO: enable interrupt on next Rx character.");
+						LOG("TODO: enable interrupt on next Rx character.");
 					break;
 					case 5:
-						LOG("[SCC] TODO: reset Tx interrupt pending.");
+						LOG("TODO: reset Tx interrupt pending.");
 					break;
 					case 6:
-						LOG("[SCC] TODO: reset error.");
+						LOG("TODO: reset error.");
 					break;
 					case 7:
-						LOG("[SCC] TODO: reset highest IUS.");
+						LOG("TODO: reset highest IUS.");
 					break;
 				}
 			break;
 
 			case 0x1:	// Write register 1 — Transmit/Receive Interrupt and Data Transfer Mode Definition.
 				interrupt_mask_ = value;
+
+				/*
+					b7 = 0 => Wait/Request output is inactive; 1 => output is informative.
+					b6 = Wait/request output is for...
+						0 => wait: floating when inactive, low if CPU is attempting to transfer data the SCC isn't yet ready for.
+						1 => request: high if inactive, low if SCC is ready to transfer data.
+					b5 = 1 => wait/request is relative to read buffer; 0 => relative to write buffer.
+
+					b4/b3:
+						00 = disable receive interrupt
+						01 = interrupt on first character or special condition
+						10 = interrupt on all characters and special conditions
+						11 = interrupt only upon special conditions.
+
+					b2 = 1 => parity error is a special condition; 0 => it isn't.
+					b1 = 1 => transmit buffer empty interrupt is enabled; 0 => it isn't.
+					b0 = 1 => external interrupt is enabled; 0 => it isn't.
+				*/
+				LOG("Interrupt mask: " << PADHEX(2) << int(value));
 			break;
 
+			case 0x2:	// Write register 2 - interrupt vector.
+			break;
+
+			case 0x3: {	// Write register 3 — Receive Parameters and Control.
+				// Get bit count.
+				int receive_bit_count = 8;
+				switch(value >> 6) {
+					default:	receive_bit_count = 5;	break;
+					case 1:		receive_bit_count = 7;	break;
+					case 2:		receive_bit_count = 6;	break;
+					case 3:		receive_bit_count = 8;	break;
+				}
+				LOG("Receive bit count: " << receive_bit_count);
+
+				(void)receive_bit_count;
+
+				/*
+					b7,b6:
+						00 = 5 receive bits per character
+						01 = 7 bits
+						10 = 6 bits
+						11 = 8 bits
+
+					b5 = 1 => DCD and CTS outputs are set automatically; 0 => they're inputs to read register 0.
+								(DCD is ignored in local loopback; CTS is ignored in both auto echo and local loopback).
+					b4: enter hunt mode (if set to 1, presumably?)
+					b3 = 1 => enable receiver CRC generation; 0 => don't.
+					b2: address search mode (SDLC)
+					b1: sync character load inhibit.
+					b0: Rx enable.
+				*/
+			} break;
+
 			case 0x4:	// Write register 4 — Transmit/Receive Miscellaneous Parameters and Modes.
 				// Bits 0 and 1 select parity mode.
 				if(!(value&1)) {
@@ -236,6 +373,23 @@ void z8530::Channel::write(bool data, uint8_t pointer, uint8_t value) {
 				}
 			break;
 
+			case 0x5:
+				// b7: DTR
+				// b6/b5:
+				//	00 = Tx 5 bits (or less) per character
+				//	01 = Tx 7 bits per character
+				//	10 = Tx 6 bits per character
+				//	11 = Tx 8 bits per character
+				// b4: send break.
+				// b3: Tx enable.
+				// b2: SDLC (if 0) / CRC-16 (if 1)
+				// b1: RTS
+				// b0: Tx CRC enable.
+			break;
+
+			case 0x6:
+			break;
+
 			case 0xf:	// Write register 15 — External/Status Interrupt Control.
 				external_interrupt_mask_ = value;
 			break;
@@ -253,12 +407,17 @@ void z8530::Channel::set_dcd(bool level) {
 	}
 }
 
-bool z8530::Channel::get_interrupt_line() {
+bool z8530::Channel::get_interrupt_line() const {
 	return
 		(interrupt_mask_ & 1) && external_status_interrupt_;
 	// TODO: other potential causes of an interrupt.
 }
 
+/*!
+	Evaluates the new level of the interrupt line and notifies the delegate if
+	both: (i) there is one; and (ii) the interrupt line has changed since last
+	the delegate was notified.
+*/
 void z8530::update_delegate() {
 	const bool interrupt_line = get_interrupt_line();
 	if(interrupt_line != previous_interrupt_line_) {

Components/8530/z8530.hpp

@@ -30,16 +30,33 @@ class z8530 {
 				A/B = A0
 				C/D = A1
 		*/
+
+		/// Performs a read from the SCC; see above for conventions as to 'address'.
 		std::uint8_t read(int address);
+		/// Performs a write to the SCC; see above for conventions as to 'address'.
 		void write(int address, std::uint8_t value);
+		/// Resets the SCC.
 		void reset();
-		bool get_interrupt_line();
+
+		/// @returns The current value of the status output: @c true for active; @c false for inactive.
+		bool get_interrupt_line() const;
 
 		struct Delegate {
-			virtual void did_change_interrupt_status(z8530 *, bool new_status) = 0;
+			/*!
+				Communicates that @c scc now has the interrupt line status @c new_status.
+			*/
+			virtual void did_change_interrupt_status(z8530 *scc, bool new_status) = 0;
 		};
+
+		/*!
+			Sets the delegate for this SCC. If this is a new delegate it is sent
+			an immediate did_change_interrupt_status message, to get it
+			up to speed.
+		*/
 		void set_delegate(Delegate *delegate) {
+			if(delegate_ == delegate) return;
 			delegate_ = delegate;
+			delegate_->did_change_interrupt_status(this, get_interrupt_line());
 		}
 
 		/*
@@ -53,7 +70,7 @@ class z8530 {
 				uint8_t read(bool data, uint8_t pointer);
 				void write(bool data, uint8_t pointer, uint8_t value);
 				void set_dcd(bool level);
-				bool get_interrupt_line();
+				bool get_interrupt_line() const;
 
 			private:
 				uint8_t data_ = 0xff;

Components/9918/9918.cpp

@@ -17,23 +17,23 @@ using namespace TI::TMS;
 
 namespace {
 
-const uint8_t StatusInterrupt = 0x80;
-const uint8_t StatusSpriteOverflow = 0x40;
+constexpr uint8_t StatusInterrupt = 0x80;
+constexpr uint8_t StatusSpriteOverflow = 0x40;
 
-const int StatusSpriteCollisionShift = 5;
-const uint8_t StatusSpriteCollision = 0x20;
+constexpr int StatusSpriteCollisionShift = 5;
+constexpr uint8_t StatusSpriteCollision = 0x20;
 
 // 342 internal cycles are 228/227.5ths of a line, so 341.25 cycles should be a whole
 // line. Therefore multiply everything by four, but set line length to 1365 rather than 342*4 = 1368.
-const unsigned int CRTCyclesPerLine = 1365;
-const unsigned int CRTCyclesDivider = 4;
+constexpr unsigned int CRTCyclesPerLine = 1365;
+constexpr unsigned int CRTCyclesDivider = 4;
 
 struct ReverseTable {
 	std::uint8_t map[256];
 
 	ReverseTable() {
 		for(int c = 0; c < 256; ++c) {
-			map[c] = static_cast<uint8_t>(
+			map[c] = uint8_t(
 				((c & 0x80) >> 7) |
 				((c & 0x40) >> 5) |
 				((c & 0x20) >> 3) |
@@ -117,10 +117,22 @@ void TMS9918::set_scan_target(Outputs::Display::ScanTarget *scan_target) {
 	crt_.set_scan_target(scan_target);
 }
 
+Outputs::Display::ScanStatus TMS9918::get_scaled_scan_status() const {
+	// The input was scaled by 3/4 to convert half cycles to internal ticks,
+	// so undo that and also allow for: (i) the multiply by 4 that it takes
+	// to reach the CRT; and (ii) the fact that the half-cycles value was scaled,
+	// and this should really reply in whole cycles.
+	return crt_.get_scaled_scan_status() * (4.0f / (3.0f * 8.0f));
+}
+
 void TMS9918::set_display_type(Outputs::Display::DisplayType display_type) {
 	crt_.set_display_type(display_type);
 }
 
+Outputs::Display::DisplayType TMS9918::get_display_type() const {
+	return crt_.get_display_type();
+}
+
 void Base::LineBuffer::reset_sprite_collection() {
 	sprites_stopped = false;
 	active_sprite_slot = 0;
@@ -132,7 +144,7 @@ void Base::LineBuffer::reset_sprite_collection() {
 
 void Base::posit_sprite(LineBuffer &buffer, int sprite_number, int sprite_position, int screen_row) {
 	if(!(status_ & StatusSpriteOverflow)) {
-		status_ = static_cast<uint8_t>((status_ & ~0x1f) | (sprite_number & 0x1f));
+		status_ = uint8_t((status_ & ~0x1f) | (sprite_number & 0x1f));
 	}
 	if(buffer.sprites_stopped)
 		return;
@@ -166,7 +178,7 @@ void TMS9918::run_for(const HalfCycles cycles) {
 	// Convert 456 clocked half cycles per line to 342 internal cycles per line;
 	// the internal clock is 1.5 times the nominal 3.579545 Mhz that I've advertised
 	// for this part. So multiply by three quarters.
-	int int_cycles = (cycles.as_int() * 3) + cycles_error_;
+	int int_cycles = int(cycles.as_integral() * 3) + cycles_error_;
 	cycles_error_ = int_cycles & 3;
 	int_cycles >>= 2;
 	if(!int_cycles) return;
@@ -178,7 +190,9 @@ void TMS9918::run_for(const HalfCycles cycles) {
 	int read_cycles_pool = int_cycles;
 
 	while(write_cycles_pool || read_cycles_pool) {
+#ifndef NDEBUG
 		LineBufferPointer backup = read_pointer_;
+#endif
 
 		if(write_cycles_pool) {
 			// Determine how much writing to do.
@@ -317,8 +331,10 @@ void TMS9918::run_for(const HalfCycles cycles) {
 		}
 
 
+#ifndef NDEBUG
 		assert(backup.row == read_pointer_.row && backup.column == read_pointer_.column);
 		backup = write_pointer_;
+#endif
 
 
 		if(read_cycles_pool) {
@@ -352,8 +368,7 @@ void TMS9918::run_for(const HalfCycles cycles) {
 				// Output video stream.
 				// --------------------
 
-#define intersect(left, right, code)	\
-	{	\
+#define intersect(left, right, code)	{	\
 		const int start = std::max(read_pointer_.column, left);	\
 		const int end = std::min(end_column, right);	\
 		if(end > start) {\
@@ -493,7 +508,7 @@ void Base::output_border(int cycles, uint32_t cram_dot) {
 	}
 }
 
-void TMS9918::set_register(int address, uint8_t value) {
+void TMS9918::write(int address, uint8_t value) {
 	// Writes to address 0 are writes to the video RAM. Store
 	// the value and return.
 	if(!(address & 1)) {
@@ -520,7 +535,7 @@ void TMS9918::set_register(int address, uint8_t value) {
 
 	// The RAM pointer is always set on a second write, regardless of
 	// whether the caller is intending to enqueue a VDP operation.
-	ram_pointer_ = (ram_pointer_ & 0x00ff) | static_cast<uint16_t>(value << 8);
+	ram_pointer_ = (ram_pointer_ & 0x00ff) | uint16_t(value << 8);
 
 	write_phase_ = false;
 	if(value & 0x80) {
@@ -625,7 +640,7 @@ void TMS9918::set_register(int address, uint8_t value) {
 
 uint8_t TMS9918::get_current_line() {
 	// Determine the row to return.
-	static const int row_change_position = 63;	// This is the proper Master System value; substitute if any other VDPs turn out to have this functionality.
+	constexpr int row_change_position = 63;	// This is the proper Master System value; substitute if any other VDPs turn out to have this functionality.
 	int source_row =
 		(write_pointer_.column < row_change_position)
 			? (write_pointer_.row + mode_timing_.total_lines - 1)%mode_timing_.total_lines
@@ -654,7 +669,7 @@ uint8_t TMS9918::get_current_line() {
 		}
 	}
 
-	return static_cast<uint8_t>(source_row);
+	return uint8_t(source_row);
 }
 
 uint8_t TMS9918::get_latched_horizontal_counter() {
@@ -671,7 +686,7 @@ void TMS9918::latch_horizontal_counter() {
 	latched_column_ = write_pointer_.column;
 }
 
-uint8_t TMS9918::get_register(int address) {
+uint8_t TMS9918::read(int address) {
 	write_phase_ = false;
 
 	// Reads from address 0 read video RAM, via the read-ahead buffer.
@@ -830,8 +845,8 @@ void Base::draw_tms_character(int start, int end) {
 		int sprite_collision = 0;
 		memset(&sprite_buffer[start], 0, size_t(end - start)*sizeof(sprite_buffer[0]));
 
-		static const uint32_t sprite_colour_selection_masks[2] = {0x00000000, 0xffffffff};
-		static const int colour_masks[16] = {0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1};
+		constexpr uint32_t sprite_colour_selection_masks[2] = {0x00000000, 0xffffffff};
+		constexpr int colour_masks[16] = {0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1};
 
 		// Draw all sprites into the sprite buffer.
 		const int shifter_target = sprites_16x16_ ? 32 : 16;

Components/9918/9918.hpp

@@ -44,9 +44,15 @@ class TMS9918: public Base {
 		/*! Sets the scan target this TMS will post content to. */
 		void set_scan_target(Outputs::Display::ScanTarget *);
 
+		/// Gets the current scan status.
+		Outputs::Display::ScanStatus get_scaled_scan_status() const;
+
 		/*! Sets the type of display the CRT will request. */
 		void set_display_type(Outputs::Display::DisplayType);
 
+		/*! Gets the type of display the CRT will request. */
+		Outputs::Display::DisplayType get_display_type() const;
+
 		/*!
 			Runs the VCP for the number of cycles indicate; it is an implicit assumption of the code
 			that the input clock rate is 3579545 Hz, the NTSC colour clock rate.
@@ -54,10 +60,10 @@ class TMS9918: public Base {
 		void run_for(const HalfCycles cycles);
 
 		/*! Sets a register value. */
-		void set_register(int address, uint8_t value);
+		void write(int address, uint8_t value);
 
 		/*! Gets a register value. */
-		uint8_t get_register(int address);
+		uint8_t read(int address);
 
 		/*! Gets the current scan line; provided by the Master System only. */
 		uint8_t get_current_line();
@@ -69,8 +75,8 @@ class TMS9918: public Base {
 		void latch_horizontal_counter();
 
 		/*!
-			Returns the amount of time until get_interrupt_line would next return true if
-			there are no interceding calls to set_register or get_register.
+			Returns the amount of time until @c get_interrupt_line would next return true if
+			there are no interceding calls to @c write or to @c read.
 
 			If get_interrupt_line is true now, returns zero. If get_interrupt_line would
 			never return true, returns -1.

Components/9918/Implementation/9918Base.hpp

@@ -40,7 +40,7 @@ enum class TVStandard {
 
 class Base {
 	public:
-		static const uint32_t palette_pack(uint8_t r, uint8_t g, uint8_t b) {
+		static uint32_t palette_pack(uint8_t r, uint8_t g, uint8_t b) {
 			uint32_t result = 0;
 			uint8_t *const result_ptr = reinterpret_cast<uint8_t *>(&result);
 			result_ptr[0] = r;
@@ -51,7 +51,7 @@ class Base {
 		}
 
 	protected:
-		const static int output_lag = 11;	// i.e. pixel output will occur 11 cycles after corresponding data read.
+		static constexpr int output_lag = 11;	// i.e. pixel output will occur 11 cycles after corresponding data read.
 
 		// The default TMS palette.
 		const uint32_t palette[16] = {
@@ -100,7 +100,7 @@ class Base {
 			// (though, in practice, it won't happen until the next
 			// external slot after this number of cycles after the
 			// device has requested the read or write).
-			return 7;
+			return 6;
 		}
 
 		// Holds the main status register.
@@ -352,9 +352,9 @@ class Base {
 					if(master_system_.cram_is_selected) {
 						// Adjust the palette.
 						master_system_.colour_ram[ram_pointer_ & 0x1f] = palette_pack(
-							static_cast<uint8_t>(((read_ahead_buffer_ >> 0) & 3) * 255 / 3),
-							static_cast<uint8_t>(((read_ahead_buffer_ >> 2) & 3) * 255 / 3),
-							static_cast<uint8_t>(((read_ahead_buffer_ >> 4) & 3) * 255 / 3)
+							uint8_t(((read_ahead_buffer_ >> 0) & 3) * 255 / 3),
+							uint8_t(((read_ahead_buffer_ >> 2) & 3) * 255 / 3),
+							uint8_t(((read_ahead_buffer_ >> 4) & 3) * 255 / 3)
 						);
 
 						// Schedule a CRAM dot; this is scheduled for wherever it should appear
@@ -421,7 +421,8 @@ class Base {
 */
 
 #define slot(n)	\
-		if(use_end && end == n) return;\
+		if(use_end && end == n) return;	\
+		[[fallthrough]];				\
 		case n
 
 #define external_slot(n)	\
@@ -449,7 +450,7 @@ class Base {
 
 
 /***********************************************
-             TMS9918 Fetching Code
+	TMS9918 Fetching Code
 ************************************************/
 
 		template<bool use_end> void fetch_tms_refresh(int start, int end) {
@@ -518,7 +519,7 @@ class Base {
 	fetch_columns_4(location+12, column+4);
 
 			LineBuffer &line_buffer = line_buffers_[write_pointer_.row];
-			const size_t row_base = pattern_name_address_ & (0x3c00 | static_cast<size_t>(write_pointer_.row >> 3) * 40);
+			const size_t row_base = pattern_name_address_ & (0x3c00 | size_t(write_pointer_.row >> 3) * 40);
 			const size_t row_offset = pattern_generator_table_address_ & (0x3800 | (write_pointer_.row & 7));
 
 			switch(start) {
@@ -693,7 +694,7 @@ class Base {
 
 
 /***********************************************
-          Master System Fetching Code
+	Master System Fetching Code
 ************************************************/
 
 		template<bool use_end> void fetch_sms(int start, int end) {
@@ -731,7 +732,7 @@ class Base {
 		const size_t scrolled_column = (column - horizontal_offset) & 0x1f;\
 		const size_t address = row_info.pattern_address_base + (scrolled_column << 1);	\
 		line_buffer.names[column].flags = ram_[address+1];	\
-		line_buffer.names[column].offset = static_cast<size_t>(	\
+		line_buffer.names[column].offset = size_t(	\
 			(((line_buffer.names[column].flags&1) << 8) | ram_[address]) << 5	\
 		) + row_info.sub_row[(line_buffer.names[column].flags&4) >> 2];	\
 	}
@@ -785,7 +786,7 @@ class Base {
 			};
 			const RowInfo scrolled_row_info = {
 				(pattern_name_address & size_t(((scrolled_row & ~7) << 3) | 0x3800)) - pattern_name_offset,
-				{static_cast<size_t>((scrolled_row & 7) << 2), 28 ^ static_cast<size_t>((scrolled_row & 7) << 2)}
+				{size_t((scrolled_row & 7) << 2), 28 ^ size_t((scrolled_row & 7) << 2)}
 			};
 			RowInfo row_info;
 			if(master_system_.vertical_scroll_lock) {

Components/AY38910/AY38910.cpp

@@ -6,51 +6,66 @@
 //  Copyright 2016 Thomas Harte. All rights reserved.
 //
 
+#include <cmath>
+
 #include "AY38910.hpp"
 
-#include <cmath>
+//namespace GI {
+//namespace AY38910 {
 
 using namespace GI::AY38910;
 
-AY38910::AY38910(Concurrency::DeferringAsyncTaskQueue &task_queue) : task_queue_(task_queue) {
-	// set up envelope lookup tables
+template <bool is_stereo>
+AY38910<is_stereo>::AY38910(Personality personality, Concurrency::DeferringAsyncTaskQueue &task_queue) : task_queue_(task_queue) {
+	// Don't use the low bit of the envelope position if this is an AY.
+	envelope_position_mask_ |= personality == Personality::AY38910;
+
+	// Set up envelope lookup tables.
 	for(int c = 0; c < 16; c++) {
-		for(int p = 0; p < 32; p++) {
+		for(int p = 0; p < 64; p++) {
 			switch(c) {
 				case 0: case 1: case 2: case 3: case 9:
-					envelope_shapes_[c][p] = (p < 16) ? (p^0xf) : 0;
-					envelope_overflow_masks_[c] = 0x1f;
+					/* Envelope: \____ */
+					envelope_shapes_[c][p] = (p < 32) ? (p^0x1f) : 0;
+					envelope_overflow_masks_[c] = 0x3f;
 				break;
 				case 4: case 5: case 6: case 7: case 15:
-					envelope_shapes_[c][p] = (p < 16) ? p : 0;
-					envelope_overflow_masks_[c] = 0x1f;
+					/* Envelope: /____ */
+					envelope_shapes_[c][p] = (p < 32) ? p : 0;
+					envelope_overflow_masks_[c] = 0x3f;
 				break;
 
 				case 8:
-					envelope_shapes_[c][p] = (p & 0xf) ^ 0xf;
+					/* Envelope: \\\\\\\\ */
+					envelope_shapes_[c][p] = (p & 0x1f) ^ 0x1f;
 					envelope_overflow_masks_[c] = 0x00;
 				break;
 				case 12:
-					envelope_shapes_[c][p] = (p & 0xf);
+					/* Envelope: //////// */
+					envelope_shapes_[c][p] = (p & 0x1f);
 					envelope_overflow_masks_[c] = 0x00;
 				break;
 
 				case 10:
-					envelope_shapes_[c][p] = (p & 0xf) ^ ((p < 16) ? 0xf : 0x0);
+					/* Envelope: \/\/\/\/ */
+					envelope_shapes_[c][p] = (p & 0x1f) ^ ((p < 32) ? 0x1f : 0x0);
 					envelope_overflow_masks_[c] = 0x00;
 				break;
 				case 14:
-					envelope_shapes_[c][p] = (p & 0xf) ^ ((p < 16) ? 0x0 : 0xf);
+					/* Envelope: /\/\/\/\ */
+					envelope_shapes_[c][p] = (p & 0x1f) ^ ((p < 32) ? 0x0 : 0x1f);
 					envelope_overflow_masks_[c] = 0x00;
 				break;
 
 				case 11:
-					envelope_shapes_[c][p] = (p < 16) ? (p^0xf) : 0xf;
-					envelope_overflow_masks_[c] = 0x1f;
+					/* Envelope: \------	(if - is high) */
+					envelope_shapes_[c][p] = (p < 32) ? (p^0x1f) : 0x1f;
+					envelope_overflow_masks_[c] = 0x3f;
 				break;
 				case 13:
-					envelope_shapes_[c][p] = (p < 16) ? p : 0xf;
-					envelope_overflow_masks_[c] = 0x1f;
+					/* Envelope: /------- */
+					envelope_shapes_[c][p] = (p < 32) ? p : 0x1f;
+					envelope_overflow_masks_[c] = 0x3f;
 				break;
 			}
 		}
@@ -59,21 +74,50 @@ AY38910::AY38910(Concurrency::DeferringAsyncTaskQueue &task_queue) : task_queue_
 	set_sample_volume_range(0);
 }
 
-void AY38910::set_sample_volume_range(std::int16_t range) {
-	// set up volume lookup table
-	const float max_volume = static_cast<float>(range) / 3.0f;	// As there are three channels.
-	const float root_two = sqrtf(2.0f);
-	for(int v = 0; v < 16; v++) {
-		volumes_[v] = static_cast<int>(max_volume / powf(root_two, static_cast<float>(v ^ 0xf)));
+template <bool is_stereo> void AY38910<is_stereo>::set_sample_volume_range(std::int16_t range) {
+	// Set up volume lookup table; the function below is based on a combination of the graph
+	// from the YM's datasheet, showing a clear power curve, and fitting that to observed
+	// values reported elsewhere.
+	const float max_volume = float(range) / 3.0f;	// As there are three channels.
+	constexpr float root_two = 1.414213562373095f;
+	for(int v = 0; v < 32; v++) {
+		volumes_[v] = int(max_volume / powf(root_two, float(v ^ 0x1f) / 3.18f));
 	}
-	volumes_[0] = 0;
+
+	// Tie level 0 to silence.
+	for(int v = 31; v >= 0; --v) {
+		volumes_[v] -= volumes_[0];
+	}
+
 	evaluate_output_volume();
 }
 
-void AY38910::get_samples(std::size_t number_of_samples, int16_t *target) {
+template <bool is_stereo> void AY38910<is_stereo>::set_output_mixing(float a_left, float b_left, float c_left, float a_right, float b_right, float c_right) {
+	a_left_ = uint8_t(a_left * 255.0f);
+	b_left_ = uint8_t(b_left * 255.0f);
+	c_left_ = uint8_t(c_left * 255.0f);
+	a_right_ = uint8_t(a_right * 255.0f);
+	b_right_ = uint8_t(b_right * 255.0f);
+	c_right_ = uint8_t(c_right * 255.0f);
+}
+
+template <bool is_stereo> void AY38910<is_stereo>::get_samples(std::size_t number_of_samples, int16_t *target) {
+	// Note on structure below: the real AY has a built-in divider of 8
+	// prior to applying its tone and noise dividers. But the YM fills the
+	// same total periods for noise and tone with double-precision envelopes.
+	// Therefore this class implements a divider of 4 and doubles the tone
+	// and noise periods. The envelope ticks along at the divide-by-four rate,
+	// but if this is an AY rather than a YM then its lowest bit is forced to 1,
+	// matching the YM datasheet's depiction of envelope level 31 as equal to
+	// programmatic volume 15, envelope level 29 as equal to programmatic 14, etc.
+
 	std::size_t c = 0;
-	while((master_divider_&7) && c < number_of_samples) {
-		target[c] = output_volume_;
+	while((master_divider_&3) && c < number_of_samples) {
+		if constexpr (is_stereo) {
+			reinterpret_cast<uint32_t *>(target)[c] = output_volume_;
+		} else {
+			target[c] = int16_t(output_volume_);
+		}
 		master_divider_++;
 		c++;
 	}
@@ -83,49 +127,53 @@ void AY38910::get_samples(std::size_t number_of_samples, int16_t *target) {
 	if(tone_counters_[c]) tone_counters_[c]--;\
 	else {\
 		tone_outputs_[c] ^= 1;\
-		tone_counters_[c] = tone_periods_[c];\
+		tone_counters_[c] = tone_periods_[c] << 1;\
 	}
 
-		// update the tone channels
+		// Update the tone channels.
 		step_channel(0);
 		step_channel(1);
 		step_channel(2);
 
 #undef step_channel
 
-		// ... the noise generator. This recomputes the new bit repeatedly but harmlessly, only shifting
+		// Update the noise generator. This recomputes the new bit repeatedly but harmlessly, only shifting
 		// it into the official 17 upon divider underflow.
 		if(noise_counter_) noise_counter_--;
 		else {
-			noise_counter_ = noise_period_;
+			noise_counter_ = noise_period_ << 1;	// To cover the double resolution of envelopes.
 			noise_output_ ^= noise_shift_register_&1;
 			noise_shift_register_ |= ((noise_shift_register_ ^ (noise_shift_register_ >> 3))&1) << 17;
 			noise_shift_register_ >>= 1;
 		}
 
-		// ... and the envelope generator. Table based for pattern lookup, with a 'refill' step: a way of
-		// implementing non-repeating patterns by locking them to table position 0x1f.
+		// Update the envelope generator. Table based for pattern lookup, with a 'refill' step: a way of
+		// implementing non-repeating patterns by locking them to the final table position.
 		if(envelope_divider_) envelope_divider_--;
 		else {
 			envelope_divider_ = envelope_period_;
 			envelope_position_ ++;
-			if(envelope_position_ == 32) envelope_position_ = envelope_overflow_masks_[output_registers_[13]];
+			if(envelope_position_ == 64) envelope_position_ = envelope_overflow_masks_[output_registers_[13]];
 		}
 
 		evaluate_output_volume();
 
-		for(int ic = 0; ic < 8 && c < number_of_samples; ic++) {
-			target[c] = output_volume_;
+		for(int ic = 0; ic < 4 && c < number_of_samples; ic++) {
+			if constexpr (is_stereo) {
+				reinterpret_cast<uint32_t *>(target)[c] = output_volume_;
+			} else {
+				target[c] = int16_t(output_volume_);
+			}
 			c++;
 			master_divider_++;
 		}
 	}
 
-	master_divider_ &= 7;
+	master_divider_ &= 3;
 }
 
-void AY38910::evaluate_output_volume() {
-	int envelope_volume = envelope_shapes_[output_registers_[13]][envelope_position_];
+template <bool is_stereo> void AY38910<is_stereo>::evaluate_output_volume() {
+	int envelope_volume = envelope_shapes_[output_registers_[13]][envelope_position_ | envelope_position_mask_];
 
 	// The output level for a channel is:
 	//	1 if neither tone nor noise is enabled;
@@ -142,9 +190,20 @@ void AY38910::evaluate_output_volume() {
 	};
 #undef level
 
-		// Channel volume is a simple selection: if the bit at 0x10 is set, use the envelope volume; otherwise use the lower four bits
+	// This remapping table seeks to map 'channel volumes', i.e. the levels produced from the
+	// 16-step progammatic volumes set per channel to 'envelope volumes', i.e. the 32-step
+	// volumes that are produced by the envelope generators (on a YM at least). My reading of
+	// the data sheet is that '0' is still off, but 15 should be as loud as peak envelope. So
+	// I've thrown in the discontinuity at the low end, where it'll be very quiet.
+	const int channel_volumes[] = {
+		0, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31
+	};
+	static_assert(sizeof(channel_volumes) == 16*sizeof(int));
+
+		// Channel volume is a simple selection: if the bit at 0x10 is set, use the envelope volume; otherwise use the lower four bits,
+		// mapped to the range 1–31 in case this is a YM.
 #define channel_volume(c)	\
-	((output_registers_[c] >> 4)&1) * envelope_volume + (((output_registers_[c] >> 4)&1)^1) * (output_registers_[c]&0xf)
+	((output_registers_[c] >> 4)&1) * envelope_volume + (((output_registers_[c] >> 4)&1)^1) * channel_volumes[output_registers_[c]&0xf]
 
 	const int volumes[3] = {
 		channel_volume(8),
@@ -153,34 +212,47 @@ void AY38910::evaluate_output_volume() {
 	};
 #undef channel_volume
 
-	// Mix additively.
-	output_volume_ = static_cast<int16_t>(
-		volumes_[volumes[0]] * channel_levels[0] +
-		volumes_[volumes[1]] * channel_levels[1] +
-		volumes_[volumes[2]] * channel_levels[2]
-	);
+	// Mix additively, weighting if in stereo.
+	if constexpr (is_stereo) {
+		int16_t *const output_volumes = reinterpret_cast<int16_t *>(&output_volume_);
+		output_volumes[0] = int16_t((
+			volumes_[volumes[0]] * channel_levels[0] * a_left_ +
+			volumes_[volumes[1]] * channel_levels[1] * b_left_ +
+			volumes_[volumes[2]] * channel_levels[2] * c_left_
+		) >> 8);
+		output_volumes[1] = int16_t((
+			volumes_[volumes[0]] * channel_levels[0] * a_right_ +
+			volumes_[volumes[1]] * channel_levels[1] * b_right_ +
+			volumes_[volumes[2]] * channel_levels[2] * c_right_
+		) >> 8);
+	} else {
+		output_volume_ = uint32_t(
+			volumes_[volumes[0]] * channel_levels[0] +
+			volumes_[volumes[1]] * channel_levels[1] +
+			volumes_[volumes[2]] * channel_levels[2]
+		);
+	}
 }
 
-bool AY38910::is_zero_level() {
+template <bool is_stereo> bool AY38910<is_stereo>::is_zero_level() const {
 	// Confirm that the AY is trivially at the zero level if all three volume controls are set to fixed zero.
 	return output_registers_[0x8] == 0 && output_registers_[0x9] == 0 && output_registers_[0xa] == 0;
 }
 
 // MARK: - Register manipulation
 
-void AY38910::select_register(uint8_t r) {
+template <bool is_stereo> void AY38910<is_stereo>::select_register(uint8_t r) {
 	selected_register_ = r;
 }
 
-void AY38910::set_register_value(uint8_t value) {
+template <bool is_stereo> void AY38910<is_stereo>::set_register_value(uint8_t value) {
 	// There are only 16 registers.
 	if(selected_register_ > 15) return;
 
 	// If this is a register that affects audio output, enqueue a mutation onto the
 	// audio generation thread.
 	if(selected_register_ < 14) {
-		const int selected_register = selected_register_;
-		task_queue_.defer([=] () {
+		task_queue_.defer([this, selected_register = selected_register_, value] () {
 			// Perform any register-specific mutation to output generation.
 			uint8_t masked_value = value;
 			switch(selected_register) {
@@ -189,7 +261,7 @@ void AY38910::set_register_value(uint8_t value) {
 					int channel = selected_register >> 1;
 
 					if(selected_register & 1)
-						tone_periods_[channel] = (tone_periods_[channel] & 0xff) | static_cast<uint16_t>((value&0xf) << 8);
+						tone_periods_[channel] = (tone_periods_[channel] & 0xff) | uint16_t((value&0xf) << 8);
 					else
 						tone_periods_[channel] = (tone_periods_[channel] & ~0xff) | value;
 				}
@@ -204,7 +276,7 @@ void AY38910::set_register_value(uint8_t value) {
 				break;
 
 				case 12:
-					envelope_period_ = (envelope_period_ & 0xff) | static_cast<int>(value << 8);
+					envelope_period_ = (envelope_period_ & 0xff) | int(value << 8);
 				break;
 
 				case 13:
@@ -242,7 +314,7 @@ void AY38910::set_register_value(uint8_t value) {
 	if(update_port_a) set_port_output(false);
 }
 
-uint8_t AY38910::get_register_value() {
+template <bool is_stereo> uint8_t AY38910<is_stereo>::get_register_value() {
 	// This table ensures that bits that aren't defined within the AY are returned as 0s
 	// when read, conforming to CPC-sourced unit tests.
 	const uint8_t register_masks[16] = {
@@ -256,24 +328,24 @@ uint8_t AY38910::get_register_value() {
 
 // MARK: - Port querying
 
-uint8_t AY38910::get_port_output(bool port_b) {
+template <bool is_stereo> uint8_t AY38910<is_stereo>::get_port_output(bool port_b) {
 	return registers_[port_b ? 15 : 14];
 }
 
 // MARK: - Bus handling
 
-void AY38910::set_port_handler(PortHandler *handler) {
+template <bool is_stereo> void AY38910<is_stereo>::set_port_handler(PortHandler *handler) {
 	port_handler_ = handler;
 	set_port_output(true);
 	set_port_output(false);
 }
 
-void AY38910::set_data_input(uint8_t r) {
+template <bool is_stereo> void AY38910<is_stereo>::set_data_input(uint8_t r) {
 	data_input_ = r;
 	update_bus();
 }
 
-void AY38910::set_port_output(bool port_b) {
+template <bool is_stereo> void AY38910<is_stereo>::set_port_output(bool port_b) {
 	// Per the data sheet: "each [IO] pin is provided with an on-chip pull-up resistor,
 	// so that when in the "input" mode, all pins will read normally high". Therefore,
 	// report programmer selection of input mode as creating an output of 0xff.
@@ -283,7 +355,7 @@ void AY38910::set_port_output(bool port_b) {
 	}
 }
 
-uint8_t AY38910::get_data_output() {
+template <bool is_stereo> uint8_t AY38910<is_stereo>::get_data_output() {
 	if(control_state_ == Read && selected_register_ >= 14 && selected_register_ < 16) {
 		// Per http://cpctech.cpc-live.com/docs/psgnotes.htm if a port is defined as output then the
 		// value returned to the CPU when reading it is the and of the output value and any input.
@@ -299,22 +371,22 @@ uint8_t AY38910::get_data_output() {
 	return data_output_;
 }
 
-void AY38910::set_control_lines(ControlLines control_lines) {
-	switch(static_cast<int>(control_lines)) {
+template <bool is_stereo> void AY38910<is_stereo>::set_control_lines(ControlLines control_lines) {
+	switch(int(control_lines)) {
 		default:					control_state_ = Inactive;		break;
 
-		case static_cast<int>(BDIR | BC2 | BC1):
+		case int(BDIR | BC2 | BC1):
 		case BDIR:
 		case BC1:					control_state_ = LatchAddress;	break;
 
-		case static_cast<int>(BC2 | BC1):		control_state_ = Read;			break;
-		case static_cast<int>(BDIR | BC2):		control_state_ = Write;			break;
+		case int(BC2 | BC1):		control_state_ = Read;			break;
+		case int(BDIR | BC2):		control_state_ = Write;			break;
 	}
 
 	update_bus();
 }
 
-void AY38910::update_bus() {
+template <bool is_stereo> void AY38910<is_stereo>::update_bus() {
 	// Assume no output, unless this turns out to be a read.
 	data_output_ = 0xff;
 	switch(control_state_) {
@@ -324,3 +396,7 @@ void AY38910::update_bus() {
 		case Read:			data_output_ = get_register_value();	break;
 	}
 }
+
+// Ensure both mono and stereo versions of the AY are built.
+template class GI::AY38910::AY38910<true>;
+template class GI::AY38910::AY38910<false>;

Components/AY38910/AY38910.hpp

@@ -30,16 +30,17 @@ class PortHandler {
 
 			@param port_b @c true if the input being queried is Port B. @c false if it is Port A.
 		*/
-		virtual uint8_t get_port_input(bool port_b) {
+		virtual uint8_t get_port_input([[maybe_unused]] bool port_b) {
 			return 0xff;
 		}
 
 		/*!
-			Requests the current input on an AY port.
+			Sets the current output on an AY port.
 
-			@param port_b @c true if the input being queried is Port B. @c false if it is Port A.
+			@param port_b @c true if the output being posted is Port B. @c false if it is Port A.
+			@param value the value now being output.
 		*/
-		virtual void set_port_output(bool port_b, uint8_t value) {}
+		virtual void set_port_output([[maybe_unused]] bool port_b, [[maybe_unused]] uint8_t value) {}
 };
 
 /*!
@@ -51,15 +52,24 @@ enum ControlLines {
 	BDIR	= (1 << 2)
 };
 
+enum class Personality {
+	/// Provides 16 volume levels to envelopes.
+	AY38910,
+	/// Provides 32 volume levels to envelopes.
+	YM2149F
+};
+
 /*!
 	Provides emulation of an AY-3-8910 / YM2149, which is a three-channel sound chip with a
 	noise generator and a volume envelope generator, which also provides two bidirectional
 	interface ports.
+
+	This AY has an attached mono or stereo mixer.
 */
-class AY38910: public ::Outputs::Speaker::SampleSource {
+template <bool is_stereo> class AY38910: public ::Outputs::Speaker::SampleSource {
 	public:
 		/// Creates a new AY38910.
-		AY38910(Concurrency::DeferringAsyncTaskQueue &task_queue);
+		AY38910(Personality, Concurrency::DeferringAsyncTaskQueue &);
 
 		/// Sets the value the AY would read from its data lines if it were not outputting.
 		void set_data_input(uint8_t r);
@@ -83,10 +93,23 @@ class AY38910: public ::Outputs::Speaker::SampleSource {
 		*/
 		void set_port_handler(PortHandler *);
 
+		/*!
+			Enables or disables stereo output; if stereo output is enabled then also sets the weight of each of the AY's
+			channels in each of the output channels.
+
+			If a_left_ = b_left = c_left = a_right = b_right = c_right = 1.0 then you'll get output that's effectively mono.
+
+			a_left = 0.0, a_right = 1.0 will make A full volume on the right output, and silent on the left.
+
+			a_left = 0.5, a_right = 0.5 will make A half volume on both outputs.
+		*/
+		void set_output_mixing(float a_left, float b_left, float c_left, float a_right = 1.0, float b_right = 1.0, float c_right = 1.0);
+
 		// to satisfy ::Outputs::Speaker (included via ::Outputs::Filter.
 		void get_samples(std::size_t number_of_samples, int16_t *target);
-		bool is_zero_level();
+		bool is_zero_level() const;
 		void set_sample_volume_range(std::int16_t range);
+		static constexpr bool get_is_stereo() { return is_stereo; }
 
 	private:
 		Concurrency::DeferringAsyncTaskQueue &task_queue_;
@@ -108,11 +131,11 @@ class AY38910: public ::Outputs::Speaker::SampleSource {
 
 		int envelope_period_ = 0;
 		int envelope_divider_ = 0;
-		int envelope_position_ = 0;
-		int envelope_shapes_[16][32];
+		int envelope_position_ = 0, envelope_position_mask_ = 0;
+		int envelope_shapes_[16][64];
 		int envelope_overflow_masks_[16];
 
-		int volumes_[16];
+		int volumes_[32];
 
 		enum ControlState {
 			Inactive,
@@ -127,14 +150,21 @@ class AY38910: public ::Outputs::Speaker::SampleSource {
 
 		uint8_t data_input_, data_output_;
 
-		int16_t output_volume_;
-		void evaluate_output_volume();
+		uint32_t output_volume_;
 
 		void update_bus();
 		PortHandler *port_handler_ = nullptr;
 		void set_port_output(bool port_b);
+
+		void evaluate_output_volume();
+
+		// Output mixing control.
+		uint8_t a_left_ = 255, a_right_ = 255;
+		uint8_t b_left_ = 255, b_right_ = 255;
+		uint8_t c_left_ = 255, c_right_ = 255;
 };
 
+
 }
 }
 

Components/AudioToggle/AudioToggle.cpp

@@ -23,16 +23,16 @@ void Toggle::set_sample_volume_range(std::int16_t range) {
 	volume_ = range;
 }
 
-void Toggle::skip_samples(const std::size_t number_of_samples) {}
+void Toggle::skip_samples(std::size_t) {}
 
 void Toggle::set_output(bool enabled) {
 	if(is_enabled_ == enabled) return;
 	is_enabled_ = enabled;
-	audio_queue_.defer([=] {
+	audio_queue_.defer([this, enabled] {
 		level_ = enabled ? volume_ : 0;
 	});
 }
 
-bool Toggle::get_output() {
+bool Toggle::get_output() const {
 	return is_enabled_;
 }

Components/AudioToggle/AudioToggle.hpp

@@ -26,7 +26,7 @@ class Toggle: public Outputs::Speaker::SampleSource {
 		void skip_samples(const std::size_t number_of_samples);
 
 		void set_output(bool enabled);
-		bool get_output();
+		bool get_output() const;
 
 	private:
 		// Accessed on the calling thread.

Components/DiskII/DiskII.cpp

@@ -78,20 +78,20 @@ void DiskII::select_drive(int drive) {
 void DiskII::run_for(const Cycles cycles) {
 	if(preferred_clocking() == ClockingHint::Preference::None) return;
 
-	int integer_cycles = cycles.as_int();
+	auto integer_cycles = cycles.as_integral();
 	while(integer_cycles--) {
 		const int address = (state_ & 0xf0) | inputs_ | ((shift_register_&0x80) >> 6);
 		if(flux_duration_) {
 			--flux_duration_;
 			if(!flux_duration_) inputs_ |= input_flux;
 		}
-		state_ = state_machine_[static_cast<std::size_t>(address)];
+		state_ = state_machine_[size_t(address)];
 		switch(state_ & 0xf) {
-			default:	shift_register_ = 0;													break;	// clear
-			case 0x8:																			break;	// nop
+			default:	shift_register_ = 0;										break;	// clear
+			case 0x8:																break;	// nop
 
-			case 0x9:	shift_register_ = static_cast<uint8_t>(shift_register_ << 1);			break;	// shift left, bringing in a zero
-			case 0xd:	shift_register_ = static_cast<uint8_t>((shift_register_ << 1) | 1);		break;	// shift left, bringing in a one
+			case 0x9:	shift_register_ = uint8_t(shift_register_ << 1);			break;	// shift left, bringing in a zero
+			case 0xd:	shift_register_ = uint8_t((shift_register_ << 1) | 1);		break;	// shift left, bringing in a one
 
 			case 0xa:	// shift right, bringing in write protected status
 				shift_register_ = (shift_register_ >> 1) | (is_write_protected() ? 0x80 : 0x00);
@@ -105,7 +105,7 @@ void DiskII::run_for(const Cycles cycles) {
 					return;
 				}
 			break;
-			case 0xb:	shift_register_ = data_input_;											break;	// load data register from data bus
+			case 0xb:	shift_register_ = data_input_;								break;	// load data register from data bus
 		}
 
 		// Currently writing?
@@ -124,7 +124,7 @@ void DiskII::run_for(const Cycles cycles) {
 	// motor switch being flipped and the drive motor actually switching off.
 	// This models that, accepting overrun as a risk.
 	if(motor_off_time_ >= 0) {
-		motor_off_time_ -= cycles.as_int();
+		motor_off_time_ -= cycles.as_integral();
 		if(motor_off_time_ < 0) {
 			set_control(Control::Motor, false);
 		}
@@ -191,7 +191,6 @@ void DiskII::set_state_machine(const std::vector<uint8_t> &state_machine) {
 				((source_address&0x02) ? 0x02 : 0x00);
 			uint8_t source_value = state_machine[source_address];
 
-			// Remap into Beneath Apple Pro-DOS value form.
 			source_value =
 				((source_value & 0x80) ? 0x10 : 0x0) |
 				((source_value & 0x40) ? 0x20 : 0x0) |
@@ -219,13 +218,13 @@ void DiskII::process_event(const Storage::Disk::Drive::Event &event) {
 	}
 }
 
-void DiskII::set_component_prefers_clocking(ClockingHint::Source *component, ClockingHint::Preference preference) {
+void DiskII::set_component_prefers_clocking(ClockingHint::Source *, ClockingHint::Preference) {
 	drive_is_sleeping_[0] = drives_[0].preferred_clocking() == ClockingHint::Preference::None;
 	drive_is_sleeping_[1] = drives_[1].preferred_clocking() == ClockingHint::Preference::None;
 	decide_clocking_preference();
 }
 
-ClockingHint::Preference DiskII::preferred_clocking() {
+ClockingHint::Preference DiskII::preferred_clocking() const {
 	return clocking_preference_;
 }
 
@@ -266,7 +265,7 @@ int DiskII::read_address(int address) {
 		break;
 		case 0xf:
 			if(!(inputs_ & input_mode))
-				drives_[active_drive_].begin_writing(Storage::Time(1, clock_rate_), false);
+				drives_[active_drive_].begin_writing(Storage::Time(1, int(clock_rate_)), false);
 			inputs_ |= input_mode;
 		break;
 	}

Components/DiskII/DiskII.hpp

@@ -26,7 +26,7 @@ namespace Apple {
 /*!
 	Provides an emulation of the Apple Disk II.
 */
-class DiskII:
+class DiskII :
 	public Storage::Disk::Drive::EventDelegate,
 	public ClockingHint::Source,
 	public ClockingHint::Observer {
@@ -48,7 +48,7 @@ class DiskII:
 			The value returned by @c read_address if accessing that address
 			didn't cause the disk II to place anything onto the bus.
 		*/
-		const int DidNotLoad = -1;
+		static constexpr int DidNotLoad = -1;
 
 		/// Advances the controller by @c cycles.
 		void run_for(const Cycles cycles);
@@ -76,7 +76,7 @@ class DiskII:
 		void set_disk(const std::shared_ptr<Storage::Disk::Disk> &disk, int drive);
 
 		// As per Sleeper.
-		ClockingHint::Preference preferred_clocking() override;
+		ClockingHint::Preference preferred_clocking() const final;
 
 		// The Disk II functions as a potential target for @c Activity::Sources.
 		void set_activity_observer(Activity::Observer *observer);
@@ -98,10 +98,10 @@ class DiskII:
 		void select_drive(int drive);
 
 		uint8_t trigger_address(int address, uint8_t value);
-		void process_event(const Storage::Disk::Drive::Event &event) override;
-		void set_component_prefers_clocking(ClockingHint::Source *component, ClockingHint::Preference preference) override;
+		void process_event(const Storage::Disk::Drive::Event &event) final;
+		void set_component_prefers_clocking(ClockingHint::Source *component, ClockingHint::Preference preference) final;
 
-		const int clock_rate_ = 0;
+		const Cycles::IntType clock_rate_ = 0;
 
 		uint8_t state_ = 0;
 		uint8_t inputs_ = 0;
@@ -109,7 +109,7 @@ class DiskII:
 
 		int stepper_mask_ = 0;
 		int stepper_position_ = 0;
-		int motor_off_time_ = -1;
+		Cycles::IntType motor_off_time_ = -1;
 
 		bool is_write_protected();
 		std::array<uint8_t, 256> state_machine_;

Components/DiskII/IWM.cpp

@@ -13,15 +13,15 @@
 using namespace Apple;
 
 namespace  {
-	const int CA0		= 1 << 0;
-	const int CA1		= 1 << 1;
-	const int CA2		= 1 << 2;
-	const int LSTRB		= 1 << 3;
-	const int ENABLE	= 1 << 4;
-	const int DRIVESEL	= 1 << 5;	/* This means drive select, like on the original Disk II. */
-	const int Q6		= 1 << 6;
-	const int Q7		= 1 << 7;
-	const int SEL		= 1 << 8;	/* This is an additional input, not available on a Disk II, with a confusingly-similar name to SELECT but a distinct purpose. */
+	constexpr int CA0		= 1 << 0;
+	constexpr int CA1		= 1 << 1;
+	constexpr int CA2		= 1 << 2;
+	constexpr int LSTRB		= 1 << 3;
+	constexpr int ENABLE	= 1 << 4;
+	constexpr int DRIVESEL	= 1 << 5;	/* This means drive select, like on the original Disk II. */
+	constexpr int Q6		= 1 << 6;
+	constexpr int Q7		= 1 << 7;
+	constexpr int SEL		= 1 << 8;	/* This is an additional input, not available on a Disk II, with a confusingly-similar name to SELECT but a distinct purpose. */
 }
 
 IWM::IWM(int clock_rate) :
@@ -233,25 +233,34 @@ void IWM::run_for(const Cycles cycles) {
 	}
 
 	// Activity otherwise depends on mode and motor state.
-	int integer_cycles = cycles.as_int();
+	auto integer_cycles = cycles.as_integral();
 	switch(shift_mode_) {
-		case ShiftMode::Reading:
+		case ShiftMode::Reading: {
+			// Per the IWM patent, column 7, around line 35 onwards: "The expected time
+			// is widened by approximately one-half an interval before and after the
+			// expected time since the data is not precisely spaced when read due to
+			// variations in drive speed and other external factors". The error_margin
+			// here implements the 'after' part of that contract.
+			const auto error_margin = Cycles(bit_length_.as_integral() >> 1);
+
 			if(drive_is_rotating_[active_drive_]) {
 				while(integer_cycles--) {
 					drives_[active_drive_]->run_for(Cycles(1));
 					++cycles_since_shift_;
-					if(cycles_since_shift_ == bit_length_ + Cycles(2)) {
+					if(cycles_since_shift_ == bit_length_ + error_margin) {
 						propose_shift(0);
 					}
 				}
 			} else {
-				while(cycles_since_shift_ + integer_cycles >= bit_length_ + Cycles(2)) {
+				while(cycles_since_shift_ + integer_cycles >= bit_length_ + error_margin) {
+					const auto run_length = bit_length_ + error_margin - cycles_since_shift_;
+					integer_cycles -= run_length.as_integral();
+					cycles_since_shift_ += run_length;
 					propose_shift(0);
-					integer_cycles -= bit_length_.as_int() + 2 - cycles_since_shift_.as_int();
 				}
 				cycles_since_shift_ += Cycles(integer_cycles);
 			}
-		break;
+		} break;
 
 		case ShiftMode::Writing:
 			if(drives_[active_drive_]->is_writing()) {
@@ -263,7 +272,7 @@ void IWM::run_for(const Cycles cycles) {
 					drives_[active_drive_]->write_bit(shift_register_ & 0x80);
 					shift_register_ <<= 1;
 
-					integer_cycles -= cycles_until_write.as_int();
+					integer_cycles -= cycles_until_write.as_integral();
 					cycles_since_shift_ = Cycles(0);
 
 					--output_bits_remaining_;
@@ -298,8 +307,8 @@ void IWM::run_for(const Cycles cycles) {
 			} else {
 				shift_register_ = sense();
 			}
+			[[fallthrough]];
 
-		/* Deliberate fallthrough. */
 		default:
 			if(drive_is_rotating_[active_drive_]) drives_[active_drive_]->run_for(cycles);
 		break;
@@ -324,7 +333,7 @@ void IWM::select_shift_mode() {
 
 	// If writing mode just began, set the drive into write mode and cue up the first output byte.
 	if(drives_[active_drive_] && old_shift_mode != ShiftMode::Writing && shift_mode_ == ShiftMode::Writing) {
-		drives_[active_drive_]->begin_writing(Storage::Time(1, clock_rate_ / bit_length_.as_int()), false);
+		drives_[active_drive_]->begin_writing(Storage::Time(1, clock_rate_ / bit_length_.as_integral()), false);
 		shift_register_ = next_output_;
 		write_handshake_ |= 0x80 | 0x40;
 		output_bits_remaining_ = 8;
@@ -351,12 +360,28 @@ void IWM::propose_shift(uint8_t bit) {
 	// TODO: synchronous mode.
 
 //	LOG("Shifting input");
+
+	// See above for text from the IWM patent, column 7, around line 35 onwards.
+	// The error_margin here implements the 'before' part of that contract.
+	//
+	// Basic effective logic: if at least 1 is fozund in the bit_length_ cycles centred
+	// on the current expected bit delivery time as implied by cycles_since_shift_,
+	// shift in a 1 and start a new window wherever the first found 1 was.
+	//
+	// If no 1s are found, shift in a 0 and don't alter expectations as to window placement.
+	const auto error_margin = Cycles(bit_length_.as_integral() >> 1);
+	if(bit && cycles_since_shift_ < error_margin) return;
+
 	shift_register_ = uint8_t((shift_register_ << 1) | bit);
 	if(shift_register_ & 0x80) {
 		data_register_ = shift_register_;
 		shift_register_ = 0;
 	}
-	cycles_since_shift_ = Cycles(0);
+
+	if(bit)
+		cycles_since_shift_ = Cycles(0);
+	else
+		cycles_since_shift_ -= bit_length_;
 }
 
 void IWM::set_drive(int slot, IWMDrive *drive) {
@@ -374,3 +399,8 @@ void IWM::set_component_prefers_clocking(ClockingHint::Source *component, Clocki
 		drive_is_rotating_[1] = is_rotating;
 	}
 }
+
+void IWM::set_activity_observer(Activity::Observer *observer) {
+	if(drives_[0]) drives_[0]->set_activity_observer(observer, "Internal Floppy", true);
+	if(drives_[1]) drives_[1]->set_activity_observer(observer, "External Floppy", true);
+}

Components/DiskII/IWM.hpp

@@ -9,8 +9,11 @@
 #ifndef IWM_hpp
 #define IWM_hpp
 
+#include "../../Activity/Observer.hpp"
+
 #include "../../ClockReceiver/ClockReceiver.hpp"
 #include "../../ClockReceiver/ClockingHintSource.hpp"
+
 #include "../../Storage/Disk/Drive.hpp"
 
 #include <cstdint>
@@ -21,7 +24,7 @@ namespace Apple {
 	Defines the drive interface used by the IWM, derived from the external pinout as
 	per e.g. https://old.pinouts.ru/HD/MacExtDrive_pinout.shtml
 
-	These are subclassed of Storage::Disk::Drive, so accept any disk the emulator supports,
+	These are subclasses of Storage::Disk::Drive, so accept any disk the emulator supports,
 	and provide the usual read/write interface for on-disk data.
 */
 struct IWMDrive: public Storage::Disk::Drive {
@@ -67,16 +70,21 @@ class IWM:
 		/// Connects a drive to the IWM.
 		void set_drive(int slot, IWMDrive *drive);
 
+		/// Registers the currently-connected drives as @c Activity::Sources ;
+		/// the first will be declared 'Internal', the second 'External'.
+		void set_activity_observer(Activity::Observer *observer);
+
 	private:
 		// Storage::Disk::Drive::EventDelegate.
-		void process_event(const Storage::Disk::Drive::Event &event) override;
+		void process_event(const Storage::Disk::Drive::Event &event) final;
 
 		const int clock_rate_;
 
 		uint8_t data_register_ = 0;
 		uint8_t mode_ = 0;
-		bool read_write_ready_ = true;
-		bool write_overran_ = false;
+		// These related to functionality not-yet implemented.
+		// bool read_write_ready_ = true;
+		// bool write_overran_ = false;
 
 		int state_ = 0;
 
@@ -84,7 +92,7 @@ class IWM:
 		IWMDrive *drives_[2] = {nullptr, nullptr};
 		bool drive_is_rotating_[2] = {false, false};
 
-		void set_component_prefers_clocking(ClockingHint::Source *component, ClockingHint::Preference clocking) override;
+		void set_component_prefers_clocking(ClockingHint::Source *component, ClockingHint::Preference clocking) final;
 
 		Cycles cycles_until_disable_;
 		uint8_t write_handshake_ = 0x80;