BizHawk/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper058.cs

76 lines
1.5 KiB
C#

using BizHawk.Common;
using BizHawk.Common.NumberExtensions;
// http://wiki.nesdev.com/w/index.php/INES_Mapper_058
namespace BizHawk.Emulation.Cores.Nintendo.NES
{
internal sealed class Mapper058 : NesBoardBase
{
bool prg_mode = false;
int chr_reg;
int prg_reg;
public override bool Configure(EDetectionOrigin origin)
{
switch (Cart.BoardType)
{
case "MAPPER058":
break;
default:
return false;
}
AssertChr(8, 16, 32, 64);
AssertPrg(16, 32, 64, 128, 256);
SetMirrorType(EMirrorType.Vertical);
return true;
}
public override void SyncState(Serializer ser)
{
ser.Sync(nameof(prg_reg), ref prg_reg);
ser.Sync(nameof(chr_reg), ref chr_reg);
ser.Sync(nameof(prg_mode), ref prg_mode);
base.SyncState(ser);
}
public override void WritePrg(int addr, byte value)
{
prg_mode = addr.Bit(6);
if (addr.Bit(7))
{
SetMirrorType(EMirrorType.Horizontal);
}
else
{
SetMirrorType(EMirrorType.Vertical);
}
prg_reg = addr & 0x07;
chr_reg = (addr >> 3) & 0x07;
}
public override byte ReadPrg(int addr)
{
if (prg_mode == false)
{
return Rom[((prg_reg >> 1) * 0x8000) + addr];
}
else
{
return Rom[(prg_reg * 0x4000) + (addr & 0x3FFF)];
}
}
public override byte ReadPpu(int addr)
{
if (addr < 0x2000)
{
return Vrom[(chr_reg * 0x2000) + addr];
}
return base.ReadPpu(addr);
}
}
}