BizHawk/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper125.cs

73 lines
1.4 KiB
C#

using BizHawk.Common;
namespace BizHawk.Emulation.Cores.Nintendo.NES
{
internal sealed class Mapper125 : NesBoardBase
{
private byte reg;
private int prg_bank_mask_8k;
public override bool Configure(EDetectionOrigin origin)
{
switch (Cart.BoardType)
{
case "MAPPER125":
case "UNIF_UNL-LH32":
break;
default:
return false;
}
SetMirrorType(Cart.PadH, Cart.PadV);
prg_bank_mask_8k = Cart.PrgSize / 8 - 1;
return true;
}
public override void SyncState(Serializer ser)
{
ser.Sync(nameof(reg), ref reg);
base.SyncState(ser);
}
public override void WriteWram(int addr, byte value)
{
if (addr == 0)
{
reg = value;
}
}
public override void WritePrg(int addr, byte value)
{
if ((addr >= 0x4000) && (addr < 0x6000))
Wram[addr - 0x4000] = value;
else
base.WritePrg(addr, value);
}
public override byte ReadPrg(int addr)
{
int bank = 0;
if (addr < 0x2000) { bank = prg_bank_mask_8k - 3; }
else if (addr < 0x4000) { bank = prg_bank_mask_8k - 2; }
// for some reason WRAM is mapped to here.
else if (addr < 0x6000)
{
return Wram[addr - 0x4000];
}
else { bank = prg_bank_mask_8k; }
bank &= prg_bank_mask_8k;
return Rom[(bank << 13) + (addr & 0x1FFF)];
}
public override byte ReadWram(int addr)
{
return Rom[((reg & prg_bank_mask_8k) << 13) + addr];
}
}
}