public Cartridge(string romFile)
{
using (FileStream fs = new FileStream(romFile, FileMode.Open, FileAccess.Read, FileShare.Read))
{
// Read in the first ROM bank, which also contains the cartridge header
rom0 = new byte[0x4000];
fs.Read(rom0, 0, 0x4000);
// Check to make sure that this is an actual GameBoy ROM File by checking the logo in the header
// (CGB only checks first 18 bytes, so that's what we will do)
for (int i = 0, addr = 0x0104; i < LogoData.Length; i++, addr++)
{
if (addr >= rom0.Length || rom0[addr] != LogoData[i])
{
throw new FileFormatException("File is not a valid GameBoy ROM");
}
}
// Get the number of ROM and RAM banks from the cartridge header.
int romSize = rom0[0x0148];
switch (romSize)
{
case 0x52: romSize = 0x4000 * 72; break; // Awkward sizes
case 0x53: romSize = 0x4000 * 80; break;
case 0x54: romSize = 0x4000 * 92; break;
default: romSize = 0x8000 << romSize; break;
}
int ramSize = rom0[0x0149];
switch (ramSize) // 0 => 0, 1 => 1
{
case 0: ramSize = 0; break;
case 1: ramSize = 0x800; break;
case 2: ramSize = 0x2000; break;
case 3: ramSize = 0x2000 * 4; break;
case 4: ramSize = 0x2000 * 16; break;
case 5: ramSize = 0x2000 * 8; break;
}
// Determine cartridge features
switch (rom0[0x0147])
{
default:
throw new NotSupportedException("Cartridge type not supported.");
case 9:
hasBattery = true;
goto case 8;
case 8:
case 0:
mbc = new ROMOnlyController(ramSize);
break;
case 3:
hasBattery = true;
goto case 2;
case 2:
case 1:
mbc = new MBC1(romSize, ramSize);
break;
case 6:
hasBattery = true;
goto case 5;
case 5:
mbc = new MBC2(romSize);
break;
case 16:
case 15:
hasBattery = true;
mbc = new MBC3(romSize, ramSize, true);
break;
case 19:
hasBattery = true;
goto case 18;
case 18:
case 17:
mbc = new MBC3(romSize, ramSize, false);
break;
}
mbc.LoadROM(fs);
}
storageFile = Path.Combine(StoragePath, Path.ChangeExtension(Path.GetFileName(romFile), BatteryExtension));
if (hasBattery && File.Exists(storageFile))
{
mbc.LoadStorageRAM(storageFile);
}
}