BizHawk/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper227.cs

122 lines
2.9 KiB
C#

using System;
using System.IO;
using System.Diagnostics;
namespace BizHawk.Emulation.Consoles.Nintendo
{
class Mapper227 : NES.NESBoardBase
{
//configuration
int prg_bank_mask_16k;
//state
int prg;
bool vram_protected;
ByteBuffer prg_banks_16k = new ByteBuffer(2);
//1200-in-1
//[NJXXX] Xiang Shuai Chuan Qi
public override bool Configure(NES.EDetectionOrigin origin)
{
//configure
switch (Cart.board_type)
{
case "MAPPER227":
//AssertVram(16);
Cart.vram_size = 16;
break;
default:
return false;
}
prg_bank_mask_16k = (Cart.prg_size / 16) - 1;
SetMirrorType(EMirrorType.Vertical);
vram_protected = false;
prg_banks_16k[0] = prg_banks_16k[1] = 0;
return true;
}
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 void WritePRG(int addr, byte value)
{
bool S = addr.Bit(0);
bool M_horz = addr.Bit(1);
int p = (addr >> 2) & 0x1F;
p += addr.Bit(8) ? 0x20 : 0;
bool o = addr.Bit(7);
bool L = addr.Bit(9);
//virtuaNES doesnt do this.
//fceux does it...
//if we do it, [NJXXX] Xiang Shuai Chuan Qi will not be able to set any patterns
//maybe only the multicarts do it, to keep the game from clobbering vram on accident
//vram_protected = o;
if (o == true && S == false)
{
prg_banks_16k[0] = (byte)(p);
prg_banks_16k[1] = (byte)(p);
}
if (o == true && S == true)
{
prg_banks_16k[0] = (byte)((p & ~1));
prg_banks_16k[1] = (byte)((p & ~1) + 1);
}
if (o == false && S == false && L == false)
{
prg_banks_16k[0] = (byte)p;
prg_banks_16k[1] = (byte)(p & 0x38);
}
if (o == false && S == true && L == false)
{
prg_banks_16k[0] = (byte)(p & 0x3E);
prg_banks_16k[1] = (byte)(p & 0x38);
}
if (o == false && S == false && L == true)
{
prg_banks_16k[0] = (byte)p;
prg_banks_16k[1] = (byte)(p | 0x07);
}
if (o == false && S == true && L == true)
{
prg_banks_16k[0] = (byte)(p & 0x3E);
prg_banks_16k[1] = (byte)(p | 0x07);
}
prg_banks_16k[0] = (byte)(prg_banks_16k[0]&prg_bank_mask_16k);
prg_banks_16k[1] = (byte)(prg_banks_16k[1]&prg_bank_mask_16k);
if (M_horz) SetMirrorType(EMirrorType.Horizontal);
else SetMirrorType(EMirrorType.Vertical);
}
public override void WritePPU(int addr, byte value)
{
if (addr < 0x2000)
{
if (vram_protected)
return;
else base.WritePPU(addr, value);
}
else base.WritePPU(addr, value);
}
public override void SyncState(Serializer ser)
{
base.SyncState(ser);
ser.Sync("prg", ref prg);
}
}
}