BizHawk/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper164.cs

65 lines
1.3 KiB
C#

using BizHawk.Common;
namespace BizHawk.Emulation.Cores.Nintendo.NES
{
internal sealed class Mapper164 : NesBoardBase
{
// http://wiki.nesdev.com/w/index.php/INES_Mapper_164
private int _prgHigh;
private int _prgLow;
private int prg_bank_mask_32k;
public override bool Configure(EDetectionOrigin origin)
{
switch (Cart.BoardType)
{
case "MAPPER164":
break;
default:
return false;
}
_prgLow = 0xFF;
prg_bank_mask_32k = Cart.PrgSize / 32 - 1;
SetMirrorType(Cart.PadH, Cart.PadV);
return true;
}
public override void WriteExp(int addr, byte value)
{
addr = (addr + 0x4000) & 0x7300;
switch (addr)
{
case 0x5000:
_prgLow = value;
break;
case 0x5100:
_prgHigh = value;
break;
}
}
public override byte ReadPrg(int addr)
{
int bank = (_prgHigh << 4) | (_prgLow & 0xF);
bank &= prg_bank_mask_32k;
return Rom[(bank * 0x8000) + (addr & 0x7FFF)];
}
public override void SyncState(Serializer ser)
{
base.SyncState(ser);
ser.Sync("prgHigh", ref _prgHigh);
ser.Sync("prgLow", ref _prgLow);
}
public override void NesSoftReset()
{
_prgHigh = 0xFF;
base.NesSoftReset();
}
}
}