commodore64: G64 disk format support

BizHawk.Emulation/BizHawk.Emulation.csproj

@@ -87,6 +87,8 @@
     <Compile Include="Computers\Commodore64\CartridgeMappers.cs" />
     <Compile Include="Computers\Commodore64\Cia.cs" />
     <Compile Include="Computers\Commodore64\DataPort.cs" />
+    <Compile Include="Computers\Commodore64\Disk.cs" />
+    <Compile Include="Computers\Commodore64\G64.cs" />
     <Compile Include="Computers\Commodore64\IMedia.cs" />
     <Compile Include="Computers\Commodore64\Input.cs" />
     <Compile Include="Computers\Commodore64\PRGFile.cs" />

BizHawk.Emulation/Computers/Commodore64/1541.cs

@@ -12,21 +12,136 @@ namespace BizHawk.Emulation.Computers.Commodore64
 		//
 		// 2kb ram, mapped 0000-07FF
 		// two 6522 VIA chips, mapped at 1800 (communication to C64) and 1C00 (drive mechanics)
+		// drive ROM, mapped C000-FFFF
 
 		public MOS6502X cpu;
+		public int cyclesPerRevolution;
+		public int cyclesPerSecond;
+		public Disk disk;
+		public byte[] ram;
+		public byte[] rom;
+		public double rpm;
 		public Via via0;
 		public Via via1;
 
-		public Drive1541()
+		public Drive1541(byte[] driveRom, Region driveRegion)
 		{
+			rom = new byte[driveRom.Length];
+			Array.Copy(driveRom, rom, driveRom.Length);
+
+			switch (driveRegion)
+			{
+				case Region.NTSC:
+					cyclesPerSecond = 14318181 / 14;
+					break;
+				case Region.PAL:
+					cyclesPerSecond = 14318181 / 18;
+					break;
+			}
 			HardReset();
 		}
 
+		public void Eject()
+		{
+			disk = null;
+		}
+
 		public void HardReset()
 		{
 			cpu = new MOS6502X();
+			ram = new byte[0x800];
 			via0 = new Via();
 			via1 = new Via();
+			SetRPM(300.0);
+		}
+
+		public void Insert(Disk newDisk)
+		{
+			disk = newDisk;
+		}
+
+		public byte Peek(ushort addr)
+		{
+			if (addr < 0x0800)
+			{
+				return ram[addr];
+			}
+			else if (addr >= 0x1800 && addr < 0x1810)
+			{
+				return via0.regs[addr];
+			}
+			else if (addr >= 0x1C00 && addr < 0x1C10)
+			{
+				return via1.regs[addr];
+			}
+			else if (addr >= 0xC000)
+			{
+				return rom[addr & 0x3FFF];
+			}
+			return 0xFF;
+		}
+
+		public void PerformCycle()
+		{
+		}
+
+		public void Poke(ushort addr, byte val)
+		{
+			if (addr < 0x0800)
+			{
+				ram[addr] = val;
+			}
+			else if (addr >= 0x1800 && addr < 0x1810)
+			{
+				via0.regs[addr] = val;
+			}
+			else if (addr >= 0x1C00 && addr < 0x1C10)
+			{
+				via1.regs[addr] = val;
+			}
+		}
+
+		public byte Read(ushort addr)
+		{
+			if (addr < 0x0800)
+			{
+				return ram[addr];
+			}
+			else if (addr >= 0x1800 && addr < 0x1810)
+			{
+				return via0.regs[addr];
+			}
+			else if (addr >= 0x1C00 && addr < 0x1C10)
+			{
+				return via1.regs[addr];
+			}
+			else if (addr >= 0xC000)
+			{
+				return rom[addr & 0x3FFF];
+			}
+			return 0xFF;
+		}
+
+		public void SetRPM(double newRPM)
+		{
+			rpm = newRPM;
+			cyclesPerRevolution = (int)((double)cyclesPerSecond / newRPM / (double)60);
+		}
+
+		public void Write(ushort addr, byte val)
+		{
+			if (addr < 0x0800)
+			{
+				ram[addr] = val;
+			}
+			else if (addr >= 0x1800 && addr < 0x1810)
+			{
+				via0.regs[addr] = val;
+			}
+			else if (addr >= 0x1C00 && addr < 0x1C10)
+			{
+				via1.regs[addr] = val;
+			}
 		}
 	}
 }

BizHawk.Emulation/Computers/Commodore64/C64.core.cs

@@ -20,6 +20,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
 
 		// source
 		public Cartridge cart;
+		public Drive1541 diskDrive;
 		public string extension;
 		public byte[] inputFile;
 		public List<IMedia> mediaAttached = new List<IMedia>();
@@ -74,6 +75,13 @@ namespace BizHawk.Emulation.Computers.Commodore64
 			// initialize media
 			switch (extension.ToUpper())
 			{
+				case @".G64":
+					diskDrive = new Drive1541(File.ReadAllBytes(Path.Combine(romPath, @"1541dos")), Region.NTSC);
+					diskDrive.Insert(G64.Read(inputFile));
+					break;
+				case @".D64":
+					diskDrive = new Drive1541(File.ReadAllBytes(Path.Combine(romPath, @"1541dos")), Region.NTSC);
+					break;
 				case @".PRG":
 					if (inputFile.Length > 2)
 						mediaAttached.Add(new PRGFile(inputFile, mem, cpu));

BizHawk.Emulation/Computers/Commodore64/Disk.cs

@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BizHawk.Emulation.Computers.Commodore64
+{
+	public class Disk
+	{
+		public class Track
+		{
+			public int bits;
+			public byte[] data;
+			public int density;
+			public int index;
+		}
+
+		public List<Track> tracks = new List<Track>();
+		public bool valid;
+	}
+}

BizHawk.Emulation/Computers/Commodore64/G64.cs

@@ -0,0 +1,62 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+
+namespace BizHawk.Emulation.Computers.Commodore64
+{
+	public static class G64
+	{
+		public static Disk Read(byte[] source)
+		{
+			MemoryStream mem = new MemoryStream(source);
+			BinaryReader reader = new BinaryReader(mem);
+			Disk result = new Disk();
+			string id = new string(reader.ReadChars(8));
+
+			if (id == @"GCR-1541")
+			{
+				int trackCount;
+				int[] trackOffsetTable = new int[84];
+				int[] trackSpeedTable = new int[84];
+
+				reader.ReadByte(); //version
+				trackCount = reader.ReadByte();
+				reader.ReadInt16(); //max track size in bytes
+
+				for (int i = 0; i < 84; i++)
+					trackOffsetTable[i] = reader.ReadInt32();
+
+				for (int i = 0; i < 84; i++)
+					trackSpeedTable[i] = reader.ReadInt32();
+
+				for (int i = 0; i < 84; i++)
+				{
+					if (trackOffsetTable[i] > 0)
+					{
+						int trackLength;
+						byte[] trackData;
+						Disk.Track track = new Disk.Track();
+
+						mem.Position = trackOffsetTable[i];
+						trackLength = reader.ReadInt16();
+						trackData = reader.ReadBytes(trackLength);
+						track.bits = trackLength * 8;
+						track.data = trackData;
+						track.density = trackSpeedTable[i];
+						track.index = i;
+						result.tracks.Add(track);
+					}
+				}
+			}
+
+			result.valid = (result.tracks.Count > 0);
+			return result;
+		}
+
+		public static void Write(Disk source)
+		{
+		}
+	}
+}

BizHawk.Emulation/Computers/Commodore64/Via.cs

@@ -18,6 +18,23 @@ namespace BizHawk.Emulation.Computers.Commodore64
 		public int SR;
 		public int[] TC;
 		public int[] TL;
+
+		public ViaRegs()
+		{
+			// power on state
+		}
+
+		public byte this[int addr]
+		{
+			get
+			{
+				return 0xFF;
+			}
+			set
+			{
+				// set register
+			}
+		}
 	}
 
 	public class Via