BizHawk/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper202.cs

62 lines
1.2 KiB
C#

using BizHawk.Common;
using BizHawk.Common.NumberExtensions;
namespace BizHawk.Emulation.Cores.Nintendo.NES
{
// 150-in-1
// http://wiki.nesdev.com/w/index.php/INES_Mapper_202
public class Mapper202 : NES.NESBoardBase
{
private int _reg;
private bool _isprg32KMode;
public override bool Configure(NES.EDetectionOrigin origin)
{
switch (Cart.board_type)
{
case "MAPPER202":
break;
default:
return false;
}
return true;
}
public override void SyncState(Serializer ser)
{
base.SyncState(ser);
ser.Sync("reg", ref _reg);
ser.Sync("isPrg32kMode", ref _isprg32KMode);
}
public override void WritePRG(int addr, byte value)
{
_reg = (addr >> 1) & 7;
_isprg32KMode = addr.Bit(0) && addr.Bit(3);
SetMirrorType(addr.Bit(0) ? EMirrorType.Horizontal : EMirrorType.Vertical);
}
public override byte ReadPRG(int addr)
{
if (_isprg32KMode)
{
return ROM[((_reg >> 1) * 0x8000) + (addr & 0x7FFF)];
}
return ROM[(_reg * 0x4000) + (addr & 0x3FFF)];
}
public override byte ReadPPU(int addr)
{
if (addr < 0x2000)
{
return VROM[(_reg * 0x2000) + (addr & 0x1FFF)];
}
return base.ReadPPU(addr);
}
}
}