BizHawk/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper176.cs

125 lines
2.7 KiB
C#

using System;
using System.IO;
using System.Diagnostics;
namespace BizHawk.Emulation.Consoles.Nintendo
{
class Mapper176 : NES.NESBoardBase
{
//configuration
int prg_bank_mask_8k, chr_bank_mask_8k;
//state
int mirror;
ByteBuffer prg_banks_8k = new ByteBuffer(4);
ByteBuffer chr_banks_8k = new ByteBuffer(1);
Bit sbw;
public override bool Configure(NES.EDetectionOrigin origin)
{
//configure
switch (Cart.board_type)
{
case "MAPPER176":
break;
default:
return false;
}
prg_bank_mask_8k = (Cart.prg_size / 8) - 1;
chr_bank_mask_8k = (Cart.chr_size / 8) - 1;
mirror = 0;
SyncMirror();
sbw = 0;
prg_banks_8k[0] = 0;
prg_banks_8k[1] = 1;
prg_banks_8k[2] = 62;
prg_banks_8k[3] = 63;
ApplyMemoryMapMask(prg_bank_mask_8k,prg_banks_8k);
chr_banks_8k[0] = 0;
ApplyMemoryMapMask(chr_bank_mask_8k, chr_banks_8k);
return true;
}
static readonly EMirrorType[] kMirrorTypes = {EMirrorType.Vertical,EMirrorType.Horizontal,EMirrorType.OneScreenA,EMirrorType.OneScreenB};
void SyncMirror()
{
SetMirrorType(kMirrorTypes[mirror]);
}
public override byte ReadPRG(int addr)
{
addr = ApplyMemoryMap(13,prg_banks_8k,addr);
return ROM[addr];
}
public override void WritePRG(int addr, byte value)
{
switch (addr)
{
case 0x2000: //0xA000
mirror = value & 3;
SyncMirror();
break;
case 0x2001: //0xA001
//we_sram = data & 0x03;
break;
}
}
public override byte ReadPPU(int addr)
{
if (addr < 0x2000)
{
addr = ApplyMemoryMap(13, chr_banks_8k, addr);
return base.ReadPPUChr(addr);
}
else return base.ReadPPU(addr);
}
void SetPrg32k(int value)
{
for(int i=0;i<4;i++)
prg_banks_8k[i] = (byte)(value * 4 + i);
ApplyMemoryMapMask(prg_bank_mask_8k, prg_banks_8k);
}
public override void WriteEXP(int addr, byte value)
{
switch (addr)
{
case 0x1000: //0x5000
break;
case 0x1001: //0x5001
if (sbw) SetPrg32k(value);
break;
case 0x1010: //0x5010
if (value == 0x24) sbw = 1;
break;
case 0x1011: //0x5011
if (sbw) SetPrg32k(value >> 1);
break;
case 0x1FF1: //0x5FF1
SetPrg32k(value>>1);
break;
case 0x1FF2: //0x5FF2
chr_banks_8k[0] = (byte)value;
ApplyMemoryMapMask(chr_bank_mask_8k, chr_banks_8k);
break;
}
}
public override void SyncState(Serializer ser)
{
base.SyncState(ser);
ser.Sync("mirror", ref mirror);
ser.Sync("prg_banks_8k", ref prg_banks_8k);
ser.Sync("chr_banks_8k", ref chr_banks_8k);
ser.Sync("sbw", ref sbw);
}
}
}