BizHawk/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper034.cs

80 lines
1.6 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace BizHawk.Emulation.Cores.Nintendo.NES
{
public sealed class Mapper034 : NES.NESBoardBase
{
// zombie board that tries to handle both bxrom and ave-nina at once
//configuration
int prg_bank_mask_32k, chr_bank_mask_4k;
//state
int[] chr = new int[2];
int prg;
public override bool Configure(NES.EDetectionOrigin origin)
{
switch (Cart.board_type)
{
case "MAPPER034": // 3-D Battles of World Runner, The (U) [b5].nes
// TODO: No idea what to assert here
break;
default:
return false;
}
Cart.wram_size = 8;
prg_bank_mask_32k = Cart.prg_size / 32 - 1;
chr_bank_mask_4k = Cart.chr_size / 4 - 1;
SetMirrorType(Cart.pad_h, Cart.pad_v);
chr[1] = 1;
return true;
}
public override byte ReadPPU(int addr)
{
if (addr < 0x2000)
return (VROM ?? VRAM)[addr & 0xfff | chr[addr >> 12] << 12];
else
return base.ReadPPU(addr);
}
public override byte ReadPRG(int addr)
{
return ROM[addr | prg << 15];
}
public override void WritePRG(int addr, byte value)
{
prg = value & prg_bank_mask_32k;
}
public override void WriteWRAM(int addr, byte value)
{
switch (addr)
{
case 0x1ffd:
prg = value & prg_bank_mask_32k;
break;
case 0x1ffe:
chr[0] = value & chr_bank_mask_4k;
break;
case 0x1fff:
chr[1] = value & chr_bank_mask_4k;
break;
default:
// on NINA, the regs sit on top of WRAM
base.WriteWRAM(addr, value);
break;
}
}
}
}