BizHawk/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Sunsoft2_m89.cs

88 lines
2.0 KiB
C#

using System;
using System.IO;
using System.Diagnostics;
namespace BizHawk.Emulation.Consoles.Nintendo
{
//AKA Sunsoft-2 chip (SUNSOFT-3 pcb)
//game=Tenka no Goikenban: Mito Koumon ; chip=sunsoft-2 ; pcb = SUNSOFT-3
//this is confusing. see docs/sunsoft.txt
class Mapper89 : NES.NESBoardBase
{
int chr;
int prg_bank_mask_16k;
byte prg_bank_16k;
ByteBuffer prg_banks_16k = new ByteBuffer(2);
public override bool Configure(NES.EDetectionOrigin origin)
{
switch (Cart.board_type)
{
case "MAPPER089":
break;
case "SUNSOFT-2":
if (Cart.pcb != "SUNSOFT-3") return false;
break;
default:
return false;
}
SetMirrorType(Cart.pad_h, Cart.pad_v);
prg_bank_mask_16k = (Cart.prg_size / 16) - 1;
prg_banks_16k[1] = 0xFF;
return true;
}
public override void Dispose()
{
prg_banks_16k.Dispose();
base.Dispose();
}
public override void SyncState(Serializer ser)
{
base.SyncState(ser);
ser.Sync("chr", ref chr);
ser.Sync("prg_bank_mask_16k", ref prg_bank_mask_16k);
ser.Sync("prg_bank_16k", ref prg_bank_16k);
ser.Sync("prg_banks_16k", ref prg_banks_16k);
}
void SyncPRG()
{
prg_banks_16k[0] = prg_bank_16k;
}
public override void WritePRG(int addr, byte value)
{
prg_bank_16k = (byte)((value >> 4) & 7);
SyncPRG();
if (value.Bit(3) == false)
SetMirrorType(EMirrorType.OneScreenA);
else
SetMirrorType(EMirrorType.OneScreenB);
chr = ((value & 0x07) + ((value >> 7) * 0x08));
}
public override byte ReadPRG(int addr)
{
int bank_16k = addr >> 14;
int ofs = addr & ((1 << 14) - 1);
bank_16k = prg_banks_16k[bank_16k];
bank_16k &= prg_bank_mask_16k;
addr = (bank_16k << 14) | ofs;
return ROM[addr];
}
public override byte ReadPPU(int addr)
{
if (addr < 0x2000)
return VROM[(addr & 0x1FFF) + (chr * 0x2000)];
else
return base.ReadPPU(addr);
}
}
}