56 lines
1.1 KiB
C#
56 lines
1.1 KiB
C#
using BizHawk.Common;
|
|
using BizHawk.Common.NumberExtensions;
|
|
|
|
// http://wiki.nesdev.com/w/index.php/INES_Mapper_231
|
|
namespace BizHawk.Emulation.Cores.Nintendo.NES
|
|
{
|
|
internal sealed class Mapper231 : NesBoardBase
|
|
{
|
|
public int prg_reg;
|
|
public int prg_bank_mask_16k;
|
|
|
|
public override bool Configure(EDetectionOrigin origin)
|
|
{
|
|
switch (Cart.BoardType)
|
|
{
|
|
case "MAPPER231":
|
|
break;
|
|
default:
|
|
return false;
|
|
}
|
|
|
|
prg_bank_mask_16k = Cart.PrgSize / 16 - 1;
|
|
return true;
|
|
}
|
|
|
|
public override void SyncState(Serializer ser)
|
|
{
|
|
ser.Sync(nameof(prg_reg), ref prg_reg);
|
|
base.SyncState(ser);
|
|
}
|
|
|
|
public override void WritePrg(int addr, byte value)
|
|
{
|
|
if (addr.Bit(7))
|
|
{
|
|
SetMirrorType(EMirrorType.Horizontal);
|
|
}
|
|
else
|
|
{
|
|
SetMirrorType(EMirrorType.Vertical);
|
|
}
|
|
|
|
int prg_reg_P = (addr >> 1) & 0xF;
|
|
int prg_reg_L = (addr >> 5) & 1;
|
|
prg_reg = (prg_reg_P<<1) | prg_reg_L;
|
|
prg_reg &= prg_bank_mask_16k;
|
|
}
|
|
|
|
public override byte ReadPrg(int addr)
|
|
{
|
|
int bank = prg_reg;
|
|
return Rom[(bank << 14) + addr - 0x4000];
|
|
}
|
|
}
|
|
}
|