Made a first attempt at Acorn ADFS support plus the start of a suitable analyser.

OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj

@@ -350,6 +350,7 @@
 		4BD14B111D74627C0088EAD6 /* StaticAnalyser.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BD14B0F1D74627C0088EAD6 /* StaticAnalyser.cpp */; };
 		4BD468F71D8DF41D0084958B /* 1770.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BD468F51D8DF41D0084958B /* 1770.cpp */; };
 		4BD5F1951D13528900631CD1 /* CSBestEffortUpdater.m in Sources */ = {isa = PBXBuildFile; fileRef = 4BD5F1941D13528900631CD1 /* CSBestEffortUpdater.m */; };
+		4BD69F941D98760000243FE1 /* AcornADF.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BD69F921D98760000243FE1 /* AcornADF.cpp */; };
 		4BE77A2E1D84ADFB00BC3827 /* File.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BE77A2C1D84ADFB00BC3827 /* File.cpp */; };
 		4BEE0A6F1D72496600532C7B /* Cartridge.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BEE0A6A1D72496600532C7B /* Cartridge.cpp */; };
 		4BEE0A701D72496600532C7B /* PRG.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BEE0A6D1D72496600532C7B /* PRG.cpp */; };
@@ -802,6 +803,8 @@
 		4BD468F61D8DF41D0084958B /* 1770.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; name = 1770.hpp; path = 1770/1770.hpp; sourceTree = "<group>"; };
 		4BD5F1931D13528900631CD1 /* CSBestEffortUpdater.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = CSBestEffortUpdater.h; path = Updater/CSBestEffortUpdater.h; sourceTree = "<group>"; };
 		4BD5F1941D13528900631CD1 /* CSBestEffortUpdater.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = CSBestEffortUpdater.m; path = Updater/CSBestEffortUpdater.m; sourceTree = "<group>"; };
+		4BD69F921D98760000243FE1 /* AcornADF.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = AcornADF.cpp; sourceTree = "<group>"; };
+		4BD69F931D98760000243FE1 /* AcornADF.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = AcornADF.hpp; sourceTree = "<group>"; };
 		4BE77A2C1D84ADFB00BC3827 /* File.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = File.cpp; path = ../../StaticAnalyser/Commodore/File.cpp; sourceTree = "<group>"; };
 		4BE77A2D1D84ADFB00BC3827 /* File.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; name = File.hpp; path = ../../StaticAnalyser/Commodore/File.hpp; sourceTree = "<group>"; };
 		4BEE0A6A1D72496600532C7B /* Cartridge.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = Cartridge.cpp; sourceTree = "<group>"; };
@@ -1133,6 +1136,8 @@
 				4B4C836F1D4F623200CD541F /* D64.hpp */,
 				4BF829611D8F536B001BAE39 /* SSD.cpp */,
 				4BF829621D8F536B001BAE39 /* SSD.hpp */,
+				4BD69F921D98760000243FE1 /* AcornADF.cpp */,
+				4BD69F931D98760000243FE1 /* AcornADF.hpp */,
 			);
 			path = Formats;
 			sourceTree = "<group>";
@@ -2113,6 +2118,7 @@
 				4BD5F1951D13528900631CD1 /* CSBestEffortUpdater.m in Sources */,
 				4B96F7221D75119A0058BB2D /* Tape.cpp in Sources */,
 				4B0BE4281D3481E700D5256B /* DigitalPhaseLockedLoop.cpp in Sources */,
+				4BD69F941D98760000243FE1 /* AcornADF.cpp in Sources */,
 				4B73C71A1D036BD90074D992 /* Vic20Document.swift in Sources */,
 				4BBF99181C8FBA6F0075DAFB /* TextureTarget.cpp in Sources */,
 				4BC76E691C98E31700E6EF73 /* FIRFilter.cpp in Sources */,

StaticAnalyser/Acorn/Disk.cpp

@@ -19,7 +19,7 @@ class FMParser: public Storage::Disk::Drive {
 		FMParser(bool is_mfm) :
 			Storage::Disk::Drive(4000000, 1, 300),
 			crc_generator_(0x1021, 0xffff),
-			shift_register_(0), track_(0)
+			shift_register_(0), track_(0), is_mfm_(is_mfm)
 		{
 			// Make sure this drive really is at track '1'.
 			while(!get_is_track_zero()) step(-1);
@@ -58,6 +58,7 @@ class FMParser: public Storage::Disk::Drive {
 		int bit_count_;
 		std::shared_ptr<Storage::Encodings::MFM::Sector> sector_cache_[65536];
 		NumberTheory::CRC16 crc_generator_;
+		bool is_mfm_;
 
 		void process_input_bit(int value, unsigned int cycles_since_index_hole)
 		{
@@ -98,7 +99,18 @@ class FMParser: public Storage::Disk::Drive {
 				while(1)
 				{
 					run_for_cycles(1);
-					if(shift_register_ == Storage::Encodings::MFM::FMIDAddressMark) break;
+					if(is_mfm_)
+					{
+						if(shift_register_ == Storage::Encodings::MFM::MFMAddressMark)
+						{
+							uint8_t mark = get_next_byte();
+							if(mark == Storage::Encodings::MFM::MFMIDAddressByte) break;
+						}
+					}
+					else
+					{
+						if(shift_register_ == Storage::Encodings::MFM::FMIDAddressMark) break;
+					}
 					if(index_count_ >= 2) return nullptr;
 				}
 
@@ -115,8 +127,20 @@ class FMParser: public Storage::Disk::Drive {
 				while(1)
 				{
 					run_for_cycles(1);
-					if(shift_register_ == Storage::Encodings::MFM::FMDataAddressMark) break;
-					if(shift_register_ == Storage::Encodings::MFM::FMIDAddressMark) return nullptr;
+					if(is_mfm_)
+					{
+						if(shift_register_ == Storage::Encodings::MFM::MFMAddressMark)
+						{
+							uint8_t mark = get_next_byte();
+							if(mark == Storage::Encodings::MFM::MFMDataAddressByte) break;
+							if(mark == Storage::Encodings::MFM::MFMIDAddressByte) return nullptr;
+						}
+					}
+					else
+					{
+						if(shift_register_ == Storage::Encodings::MFM::FMDataAddressMark) break;
+						if(shift_register_ == Storage::Encodings::MFM::FMIDAddressMark) return nullptr;
+					}
 					if(index_count_ >= 2) return nullptr;
 				}
 
@@ -165,7 +189,7 @@ std::unique_ptr<Catalogue> StaticAnalyser::Acorn::GetDFSCatalogue(const std::sha
 	std::shared_ptr<Storage::Encodings::MFM::Sector> names = parser.get_sector(0, 0);
 	std::shared_ptr<Storage::Encodings::MFM::Sector> details = parser.get_sector(0, 1);
 
-	if(!names || !details) return catalogue;
+	if(!names || !details) return nullptr;
 	if(names->data.size() != 256 || details->data.size() != 256) return nullptr;
 
 	uint8_t final_file_offset = details->data[5];

StaticAnalyser/Acorn/StaticAnalyser.cpp

@@ -69,6 +69,7 @@ void StaticAnalyser::Acorn::AddTargets(
 	target.probability = 1.0; // TODO: a proper estimation
 	target.acorn.has_dfs = false;
 	target.acorn.has_adfs = false;
+	target.acorn.should_hold_shift = false;
 
 	// strip out inappropriate cartridges
 	target.cartridges = AcornCartridgesFrom(cartridges);
@@ -116,14 +117,15 @@ void StaticAnalyser::Acorn::AddTargets(
 	if(disks.size() > 0)
 	{
 		std::shared_ptr<Storage::Disk::Disk> disk = disks.front();
-		std::unique_ptr<Catalogue> catalogue = GetDFSCatalogue(disk);
-		if(catalogue == nullptr) catalogue = GetADFSCatalogue(disk);
-		if(catalogue)
+		std::unique_ptr<Catalogue> dfs_catalogue, adfs_catalogue;
+		dfs_catalogue = GetDFSCatalogue(disk);
+		if(dfs_catalogue == nullptr) adfs_catalogue = GetADFSCatalogue(disk);
+		if(dfs_catalogue || adfs_catalogue)
 		{
 			target.disks = disks;
-			target.acorn.has_dfs = true;
+			target.acorn.has_dfs = !!dfs_catalogue;
 
-			switch(catalogue->bootOption)
+			switch((dfs_catalogue ?: adfs_catalogue)->bootOption)
 			{
 				case Catalogue::BootOption::None:	target.loadingCommand = "*CAT\n";		break;
 				default:							target.acorn.should_hold_shift = true;	break;

StaticAnalyser/StaticAnalyser.cpp

@@ -20,6 +20,7 @@
 #include "../Storage/Cartridge/Formats/PRG.hpp"
 
 // Disks
+#include "../Storage/Disk/Formats/AcornADF.hpp"
 #include "../Storage/Disk/Formats/D64.hpp"
 #include "../Storage/Disk/Formats/G64.hpp"
 #include "../Storage/Disk/Formats/SSD.hpp"
@@ -80,6 +81,7 @@ std::list<Target> StaticAnalyser::GetTargets(const char *file_name)
 	}
 
 	Format("a26", cartridges, Cartridge::BinaryDump, TargetPlatform::Atari2600)		// A26
+	Format("adf", disks, Disk::AcornADF, TargetPlatform::Acorn)						// ADF
 	Format("bin", cartridges, Cartridge::BinaryDump, TargetPlatform::Atari2600)		// BIN
 	Format("d64", disks, Disk::D64, TargetPlatform::Commodore)						// D64
 	Format("dsd", disks, Disk::SSD, TargetPlatform::Acorn)							// DSD

Storage/Disk/Encodings/MFM.cpp

@@ -49,23 +49,23 @@ template <class T> class MFMShifter: public Shifter<T> {
 		}
 
 		void add_index_address_mark() {
-			static_cast<T *>(this)->output_short(output_ = 0x5224);
-			add_byte(0xfc);
+			static_cast<T *>(this)->output_short(output_ = MFMIndexAddressMark);
+			add_byte(MFMIndexAddressByte);
 		}
 
 		void add_ID_address_mark() {
-			static_cast<T *>(this)->output_short(output_ = 0x4489);
-			add_byte(0xfe);
+			static_cast<T *>(this)->output_short(output_ = MFMAddressMark);
+			add_byte(MFMIDAddressByte);
 		}
 
 		void add_data_address_mark() {
-			static_cast<T *>(this)->output_short(output_ = 0x4489);
-			add_byte(0xfb);
+			static_cast<T *>(this)->output_short(output_ = MFMAddressMark);
+			add_byte(MFMDataAddressByte);
 		}
 
 		void add_deleted_data_address_mark() {
-			static_cast<T *>(this)->output_short(output_ = 0x4489);
-			add_byte(0xf8);
+			static_cast<T *>(this)->output_short(output_ = MFMAddressMark);
+			add_byte(MFMDeletedDataAddressByte);
 		}
 
 	private:

Storage/Disk/Encodings/MFM.hpp

@@ -22,6 +22,13 @@ const uint16_t FMIDAddressMark			= 0xf57e;	// data 0xfe, with clock 0xc7 => 1111
 const uint16_t FMDataAddressMark		= 0xf56f;	// data 0xfb, with clock 0xc7 => 1111 1011 with clock 1100 0111 => 1111 0101 0110 1111
 const uint16_t FMDeletedDataAddressMark	= 0xf56a;	// data 0xf8, with clock 0xc7 => 1111 1000 with clock 1100 0111 => 1111 0101 0110 1010
 
+const uint16_t MFMIndexAddressMark		= 0x5224;
+const uint16_t MFMAddressMark			= 0x4489;
+const uint8_t MFMIndexAddressByte		= 0xfc;
+const uint8_t MFMIDAddressByte			= 0xfe;
+const uint8_t MFMDataAddressByte		= 0xfb;
+const uint8_t MFMDeletedDataAddressByte	= 0xf8;
+
 
 struct Sector {
 	uint8_t track, side, sector;

Storage/Disk/Formats/AcornADF.cpp

@@ -0,0 +1,82 @@
+//
+//  AcornADF.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 25/09/2016.
+//  Copyright © 2016 Thomas Harte. All rights reserved.
+//
+
+#include "AcornADF.hpp"
+
+#include <sys/stat.h>
+#include "../Encodings/MFM.hpp"
+
+using namespace Storage::Disk;
+
+AcornADF::AcornADF(const char *file_name) : _file(nullptr)
+{
+	struct stat file_stats;
+	stat(file_name, &file_stats);
+
+	// very loose validation: the file needs to be a multiple of 256 bytes
+	// and not ungainly large
+	if(file_stats.st_size & 255) throw ErrorNotAcornADF;
+	if(file_stats.st_size < 2048) throw ErrorNotAcornADF;
+
+	_file = fopen(file_name, "rb");
+	if(!_file) throw ErrorCantOpen;
+
+	// check that the initial directory's 'Hugo's are present
+	fseek(_file, 513, SEEK_SET);
+	uint8_t bytes[4];
+	fread(bytes, 1, 4, _file);
+	if(bytes[0] != 'H' || bytes[1] != 'u' || bytes[2] != 'g' || bytes[3] != 'o') throw ErrorNotAcornADF;
+
+	fseek(_file, 0x6fb, SEEK_SET);
+	fread(bytes, 1, 4, _file);
+	if(bytes[0] != 'H' || bytes[1] != 'u' || bytes[2] != 'g' || bytes[3] != 'o') throw ErrorNotAcornADF;
+}
+
+AcornADF::~AcornADF()
+{
+	if(_file) fclose(_file);
+}
+
+unsigned int AcornADF::get_head_position_count()
+{
+	return 80;
+}
+
+unsigned int AcornADF::get_head_count()
+{
+	return 2;
+}
+
+std::shared_ptr<Track> AcornADF::get_track_at_position(unsigned int head, unsigned int position)
+{
+	std::shared_ptr<Track> track;
+
+	if(head >= 2) return track;
+	long file_offset = (position * 2 + head) * 256 * 16;
+	fseek(_file, file_offset, SEEK_SET);
+
+	std::vector<Storage::Encodings::MFM::Sector> sectors;
+	for(int sector = 0; sector < 16; sector++)
+	{
+		Storage::Encodings::MFM::Sector new_sector;
+		new_sector.track = (uint8_t)position;
+		new_sector.side = 0;
+		new_sector.sector = (uint8_t)sector;
+
+		new_sector.data.resize(256);
+		fread(&new_sector.data[0], 1, 256, _file);
+		if(feof(_file))
+			break;
+
+		sectors.push_back(std::move(new_sector));
+	}
+
+	if(sectors.size()) return Storage::Encodings::MFM::GetMFMTrackWithSectors(sectors);
+
+	return track;
+}

Storage/Disk/Formats/AcornADF.hpp

@@ -0,0 +1,48 @@
+//
+//  AcornADF.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 25/09/2016.
+//  Copyright © 2016 Thomas Harte. All rights reserved.
+//
+
+#ifndef AcornADF_hpp
+#define AcornADF_hpp
+
+#include "../Disk.hpp"
+
+namespace Storage {
+namespace Disk {
+
+/*!
+	Provies a @c Disk containing an ADF disk image — a decoded sector dump of an Acorn ADFS disk.
+*/
+class AcornADF: public Disk {
+	public:
+		/*!
+			Construct an @c AcornADF containing content from the file with name @c file_name.
+
+			@throws ErrorCantOpen if this file can't be opened.
+			@throws ErrorNotAcornADF if the file doesn't appear to contain an Acorn .ADF format image.
+		*/
+		AcornADF(const char *file_name);
+		~AcornADF();
+
+		enum {
+			ErrorCantOpen,
+			ErrorNotAcornADF,
+		};
+
+		// implemented to satisfy @c Disk
+		unsigned int get_head_position_count();
+		unsigned int get_head_count();
+		std::shared_ptr<Track> get_track_at_position(unsigned int head, unsigned int position);
+
+	private:
+		FILE *_file;
+};
+
+}
+}
+
+#endif /* AcornADF_hpp */

Storage/Disk/Formats/SSD.cpp

@@ -69,7 +69,8 @@ std::shared_ptr<Track> SSD::get_track_at_position(unsigned int head, unsigned in
 
 		new_sector.data.resize(256);
 		fread(&new_sector.data[0], 1, 256, _file);
-		if(feof(_file)) break;
+		if(feof(_file))
+			break;
 
 		sectors.push_back(std::move(new_sector));
 	}

Storage/Disk/Formats/SSD.hpp

@@ -20,10 +20,10 @@ namespace Disk {
 class SSD: public Disk {
 	public:
 		/*!
-			Construct a @c D64 containing content from the file with name @c file_name.
+			Construct an @c SSD containing content from the file with name @c file_name.
 
 			@throws ErrorCantOpen if this file can't be opened.
-			@throws ErrorNotD64 if the file doesn't appear to contain a .D64 format image.
+			@throws ErrorNotSSD if the file doesn't appear to contain a .SSD format image.
 		*/
 		SSD(const char *file_name);
 		~SSD();