private void FastWrite(byte i, bool value)
{
var updated = FastBits.Get(registerValue);
updated[i] = value;
registerValue = FastBits.Write(updated);
}
public void HardReset()
{
Control = new ControlRegisterValues(0);
Mask = new MaskRegisterValues(0);
Status = new StatusRegisterValues(0);
FastBits.Clear(ImageBuffer);
isFrameOdd = false;
CurrentScanline = 0;
CurrentDot = 0;
Memory.HardReset();
}
public NesCartHeader(
byte[] fileId,
byte prgRomPages,
byte chrRomPages,
byte cartTypeLsb,
byte cartTypeMsb,
byte prgRamPages,
byte tvSystem1,
byte tvSystem2,
byte[] padding
)
{
this.FileId = fileId;
this.PrgRomPages = prgRomPages;
this.ChrRomPages = chrRomPages;
this.CartTypeLsb = FastBits.Get(cartTypeLsb);
this.CartTypeMsb = FastBits.Get(cartTypeMsb);
this.PrgRamPages = prgRamPages;
this.TvSystem1 = tvSystem1;
this.TvSystem2 = tvSystem2;
this.Padding = padding;
this.MapperNumber = (byte)(((cartTypeLsb & 0xF0) >> 4) | (cartTypeMsb & 0xF0));
}
protected override bool WriteRegister(ushort i, byte d)
{
if (i < 0x8000)
{
return(false);
}
ushort baseline = (ushort)(i & 0xE001);
var bits = FastBits.Get(d);
switch (baseline)
{
case 0x8000:
// Bank select
NextWriteBank = (byte)(d & 0x7);
PrgRomBankMode = bits[6];
ChrA12InversionMode = bits[7];
return(true);
case 0x8001:
// Bank data
if (NextWriteBank == 0 || NextWriteBank == 1)
{
Registers[NextWriteBank] = (byte)(d & 0x1);
}
else
{
Registers[NextWriteBank] = d;
}
return(true);
case 0xA000:
// Mirroring
NametableMirroring = bits[0];
Nes.Ppu.MirrorMode = NametableMirroring ? MirrorMode.Horizontal : MirrorMode.Vertical;
return(true);
case 0xA001:
// PRG RAM protect
PrgRamWritesDisabled = bits[6];
PrgRamEnabled = bits[7];
return(true);
case 0xC000:
// IRQ latch
IRQPeriod = d;
return(true);
case 0xC001:
// IRQ reload
IRQCounter = 0;
return(true);
case 0xE000:
// IRQ disable
IRQEnabled = false;
Nes.Cpu.ActiveIrq = false;
return(true);
case 0xE001:
// IRQ enable
IRQEnabled = true;
return(true);
}
return(false);
}
private bool FastRead(byte i)
{
return(FastBits.Get(registerValue)[7 - i]);
}
private void FastWrite(byte i, bool value)
{
registerValue = FastBits.Set(registerValue, (byte)(7 - i), value);
}
public void HardReset()
{
FastBits.Clear(BidirectionalIO, 0xFF);
FastBits.Clear(WorkingRam, 0xFF);
}
public void HardReset()
{
FastBits.Clear(Vram);
FastBits.Clear(PaletteRAM);
FastBits.Clear(OAMram);
}
