} = 0x0000; // 16-bit
public AudioHardware(ROMData romData, ROMSet romset = ROMSet.PacMan)
{
if (romset != ROMSet.PacMan && romset != ROMSet.MsPacMan)
{
throw new ArgumentException($"Unexpected ROM set: {romset}");
}
_romset = romset;
var rom1 = romData.Data[ROMs.PAC_MAN_SOUND_1.FileName];
var rom2 = romData.Data[ROMs.PAC_MAN_SOUND_2.FileName];
_soundROMs = new byte[512];
Array.Copy(rom1, 0, _soundROMs, 0, 256);
Array.Copy(rom2, 0, _soundROMs, 256, 256);
}
public VideoHardware(ROMData romData, ROMSet romset = ROMSet.PacMan)
{
if (romset != ROMSet.PacMan && romset != ROMSet.MsPacMan)
{
throw new ArgumentException($"Unexpected ROM set: {romset}");
}
_romset = romset;
_colorROM = romData.Data[ROMs.PAC_MAN_COLOR.FileName];
_paletteROM = romData.Data[ROMs.PAC_MAN_PALETTE.FileName];
_tileROM = romData.Data[romset == ROMSet.MsPacMan ? ROMs.MS_PAC_MAN_TILE.FileName : ROMs.PAC_MAN_TILE.FileName];
_spriteROM = romData.Data[romset == ROMSet.MsPacMan ? ROMs.MS_PAC_MAN_SPRITE.FileName : ROMs.PAC_MAN_SPRITE.FileName];
_frameBuffer = new Image <Rgba32>(RESOLUTION_WIDTH, RESOLUTION_HEIGHT, new Rgba32()
{
R = 0, G = 0, B = 0, A = 255
});
}
/**
* Used to start execution of the CPU with the given ROM and optional emulator state.
* The emulator's hardware loop will run on a spereate thread, and therefore, this method
* is non-blocking.
*/
public void Start(ROMData romData, EmulatorState state = null)
{
if (_thread != null)
{
throw new Exception("Emulator cannot be started because it was already running.");
}
if (romData == null || romData.Data == null || romData.Data.Count == 0)
{
throw new Exception("romData is required.");
}
if (ROMSet != ROMSet.PacMan && ROMSet != ROMSet.MsPacMan)
{
throw new ArgumentException($"Unexpected ROM set: {ROMSet}");
}
// The initial configuration of the CPU.
var cpuConfig = new CPUConfig()
{
Registers = new CPURegisters()
{
PC = 0x0000,
// Hardcode the stackpointer to the top of the RAM.
// TODO: Is this different for each game that runs on the Pac-Man hardware?
SP = 0x4FEF,
},
// Interrupts are initially disabled, and will be enabled by the program ROM when ready.
InterruptsEnabled = false,
// Diagnostics is only for unit tests.
EnableDiagnosticsMode = false,
};
// Initialize the CPU and subscribe to device events.
_cpu = new CPU(cpuConfig);
_cpu.OnDeviceRead += CPU_OnDeviceRead;
_cpu.OnDeviceWrite += CPU_OnDeviceWrite;
_cyclesSinceLastInterrupt = 0;
// Fetch the ROM data; we trust the contents were validated with a CRC32 check elsewhere, but
// since the CRC check can be bypassed, we at least need to ensure the file sizes are correct
// since this classes' implementation of IMemory is expecting certain addreses.
var codeRom1 = romData.Data[ROMs.PAC_MAN_CODE_1.FileName];
var codeRom2 = romData.Data[ROMs.PAC_MAN_CODE_2.FileName];
var codeRom3 = romData.Data[ROMs.PAC_MAN_CODE_3.FileName];
var codeRom4 = romData.Data[ROMs.PAC_MAN_CODE_4.FileName];
if (codeRom1.Length != 4096 || codeRom2.Length != 4096 || codeRom3.Length != 4096 || codeRom4.Length != 4096)
{
throw new Exception("All code ROMs must be exactly 4KB in size.");
}
// Define our addressable memory space, which includes the game code ROMS and RAM.
var addressableMemorySize =
codeRom1.Length // Code ROM 1
+ codeRom2.Length // Code ROM 2
+ codeRom3.Length // Code ROM 3
+ codeRom4.Length // Code ROM 4
+ 1024 // Video RAM (tile information)
+ 1024 // Video RAM (tile palettes)
+ 2032 // RAM
+ 16; // Sprite numbers
_memory = new byte[addressableMemorySize];
// Map the code ROM into the lower 16K of the memory space.
Array.Copy(codeRom1, 0, _memory, 0, codeRom1.Length);
Array.Copy(codeRom2, 0, _memory, codeRom1.Length, codeRom2.Length);
Array.Copy(codeRom3, 0, _memory, codeRom1.Length + codeRom2.Length, codeRom3.Length);
Array.Copy(codeRom4, 0, _memory, codeRom1.Length + codeRom2.Length + codeRom3.Length, codeRom4.Length);
// Load and decrypt the Ms. Pac-Man daughterboard ROMs and apply patches to the base Pac-Man ROMs.
// The patches will be applied to a seperate memory instance because we still need the original,
// unmodified Pac-Man code ROMs present to boot and pass the self-test. See PacManPCB::Read().
if (ROMSet == ROMSet.MsPacMan)
{
_auxBoard = new MsPacManAuxBoard();
_auxBoard.LoadAuxROMs(romData);
}
// This class implements the IMemory interface, which the CPU needs to determine how to read and
// write data. We set the reference to this class instance (whose implementation uses _memory).
_cpu.Memory = this;
// Initialize video hardware.
_video = new VideoHardware(romData, ROMSet);
_video.Initialize();
// Initialize audio hardware.
_audio = new AudioHardware(romData, ROMSet);
if (state != null)
{
LoadState(state);
}
_cancelled = false;
_thread = new Thread(new ThreadStart(HardwareLoop));
_thread.Name = "Pac-Man Hardware";
_thread.Start();
}
public static ROMData LoadFromDisk(ROMSet romset, string directoryPath, bool enforceValidChecksum = true)
{
var romData = new ROMData();
List <ROMFile> romFiles = null;
if (romset == ROMSet.PacMan)
{
romFiles = ROMs.PAC_MAN;
}
else if (romset == ROMSet.MsPacMan)
{
romFiles = ROMs.MS_PAC_MAN;
}
else
{
throw new ArgumentException($"Unexpected romset: {romset}");
}
foreach (var romFile in romFiles)
{
var path = Path.Combine(directoryPath, romFile.FileName);
string alternatePath = null;
if (!String.IsNullOrWhiteSpace(romFile.AlternateFileName))
{
alternatePath = Path.Combine(directoryPath, romFile.AlternateFileName);
}
byte[] rom = null;
// Attempt to load the ROM file data from the primary and secondary file names.
if (File.Exists(path))
{
rom = File.ReadAllBytes(path);
}
if (!String.IsNullOrWhiteSpace(alternatePath) && File.Exists(alternatePath))
{
rom = File.ReadAllBytes(alternatePath);
}
var alternateFileNameMessage = romFile.AlternateFileName == null ? "" : $"(or alternate name '{romFile.AlternateFileName}')";
if (rom == null)
{
throw new Exception($"Could not locate the '{romFile.Description}' ROM file '{romFile.FileName}'{alternateFileNameMessage} with CRC32 of '{romFile.CRC32}' at the location: {path}");
}
// The ROM size should always match.
if (romFile.Size != rom.Length)
{
throw new Exception($"The file size for '{romFile.Description}' ROM file '{romFile.FileName}'{alternateFileNameMessage} at the location: {path} was {rom.Length} bytes, but we are expecting {romFile.Size} bytes.");
}
// Perform a quick checksum to determine if we got the correct file.
var crc32 = new CRC32();
var checksum = crc32.Get(rom).ToString("X8");
if (checksum != romFile.CRC32)
{
var message = $"The CRC32 checksum for '{romFile.Description}' ROM file '{romFile.FileName}'{alternateFileNameMessage} at the location: {path} was calculated as '{checksum}', but we are expecting '{romFile.CRC32}'.";
if (enforceValidChecksum)
{
throw new Exception(message);
}
else
{
Console.WriteLine($"[WARNING] {message}");
}
}
// Add the binary ROM data to the set indexed by file name.
romData.Data[romFile.FileName] = rom;
}
return(romData);
}
public void LoadAuxROMs(ROMData romData)
{
// Decrypt Ms. Pac-Man aux board ROMs U5, U6, U7.
var u5 = romData.Data[ROMs.MS_PAC_MAN_AUX_U5.FileName];
var u6 = romData.Data[ROMs.MS_PAC_MAN_AUX_U6.FileName];
var u7 = romData.Data[ROMs.MS_PAC_MAN_AUX_U7.FileName];
// Original ROMs: 16K
// New ROMs: 10K
AuxROMs = new byte[(16 + 10) * 1024];
for (var i = 0; i < 0x1000; i++)
{
AuxROMs[DecryptAddress1((uint)i) + 0x4000] = (byte)DecryptData(u7[i]);
AuxROMs[DecryptAddress1((uint)i) + 0x5000] = (byte)DecryptData(u6[i]);
}
for (var i = 0; i < 0x0800; i++)
{
AuxROMs[DecryptAddress2((uint)i) + 0x6000] = (byte)DecryptData(u5[i]);
}
// Copy the original Pac-Man ROM, expect for code ROM 4 (6J) which is replaced
// completely by aux ROM U7. We'll also be applying patches to these below.
var codeRom1 = romData.Data[ROMs.PAC_MAN_CODE_1.FileName];
var codeRom2 = romData.Data[ROMs.PAC_MAN_CODE_2.FileName];
var codeRom3 = romData.Data[ROMs.PAC_MAN_CODE_3.FileName];
Array.Copy(codeRom1, 0, AuxROMs, 0x0000, 0x1000);
Array.Copy(codeRom2, 0, AuxROMs, 0x1000, 0x1000);
Array.Copy(codeRom3, 0, AuxROMs, 0x2000, 0x1000);
Array.Copy(AuxROMs, 0x4000, AuxROMs, 0x3000, 0x1000);
// The U5 ROM contains patches to the original Pac-Man ROMs 1-3 (6E/6F/6H).
// This list of patch locations was determined by looking at MAME and PIE.
// https://www.walkofmind.com/programming/pie/pie.htm
// https://github.com/mamedev/mame/blob/master/src/mame/drivers/pacman.cpp#L7366
// Technically the aux board has latches that "overlay" reads from these addresses
// however, it's good enough to just replace the bytes in our case.
for (var i = 0; i < 8; i++)
{
AuxROMs[0x0410 + i] = AuxROMs[0x6008 + i];
AuxROMs[0x08E0 + i] = AuxROMs[0x61D8 + i];
AuxROMs[0x0A30 + i] = AuxROMs[0x6118 + i];
AuxROMs[0x0BD0 + i] = AuxROMs[0x60D8 + i];
AuxROMs[0x0C20 + i] = AuxROMs[0x6120 + i];
AuxROMs[0x0E58 + i] = AuxROMs[0x6168 + i];
AuxROMs[0x0EA8 + i] = AuxROMs[0x6198 + i];
AuxROMs[0x1000 + i] = AuxROMs[0x6020 + i];
AuxROMs[0x1008 + i] = AuxROMs[0x6010 + i];
AuxROMs[0x1288 + i] = AuxROMs[0x6098 + i];
AuxROMs[0x1348 + i] = AuxROMs[0x6048 + i];
AuxROMs[0x1688 + i] = AuxROMs[0x6088 + i];
AuxROMs[0x16B0 + i] = AuxROMs[0x6188 + i];
AuxROMs[0x16D8 + i] = AuxROMs[0x60C8 + i];
AuxROMs[0x16F8 + i] = AuxROMs[0x61C8 + i];
AuxROMs[0x19A8 + i] = AuxROMs[0x60A8 + i];
AuxROMs[0x19B8 + i] = AuxROMs[0x61A8 + i];
AuxROMs[0x2060 + i] = AuxROMs[0x6148 + i];
AuxROMs[0x2108 + i] = AuxROMs[0x6018 + i];
AuxROMs[0x21A0 + i] = AuxROMs[0x61A0 + i];
AuxROMs[0x2298 + i] = AuxROMs[0x60A0 + i];
AuxROMs[0x23E0 + i] = AuxROMs[0x60E8 + i];
AuxROMs[0x2418 + i] = AuxROMs[0x6000 + i];
AuxROMs[0x2448 + i] = AuxROMs[0x6058 + i];
AuxROMs[0x2470 + i] = AuxROMs[0x6140 + i];
AuxROMs[0x2488 + i] = AuxROMs[0x6080 + i];
AuxROMs[0x24B0 + i] = AuxROMs[0x6180 + i];
AuxROMs[0x24D8 + i] = AuxROMs[0x60C0 + i];
AuxROMs[0x24F8 + i] = AuxROMs[0x61C0 + i];
AuxROMs[0x2748 + i] = AuxROMs[0x6050 + i];
AuxROMs[0x2780 + i] = AuxROMs[0x6090 + i];
AuxROMs[0x27B8 + i] = AuxROMs[0x6190 + i];
AuxROMs[0x2800 + i] = AuxROMs[0x6028 + i];
AuxROMs[0x2B20 + i] = AuxROMs[0x6100 + i];
AuxROMs[0x2B30 + i] = AuxROMs[0x6110 + i];
AuxROMs[0x2BF0 + i] = AuxROMs[0x61D0 + i];
AuxROMs[0x2CC0 + i] = AuxROMs[0x60D0 + i];
AuxROMs[0x2CD8 + i] = AuxROMs[0x60E0 + i];
AuxROMs[0x2CF0 + i] = AuxROMs[0x61E0 + i];
AuxROMs[0x2D60 + i] = AuxROMs[0x6160 + i];
}
}
