BizHawk/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper036.cs

105 lines
2.1 KiB
C#

using BizHawk.Common;
using BizHawk.Common.NumberExtensions;
using System;
namespace BizHawk.Emulation.Cores.Nintendo.NES
{
// mapper036
// Strike Wolf (MGC-014) [!].nes
// Using https://wiki.nesdev.com/w/index.php/INES_Mapper_036
public sealed class Mapper036 : NES.NESBoardBase
{
int chr;
int prg;
int chr_mask;
int prg_mask;
byte R;
bool M;
byte P;
public override bool Configure(NES.EDetectionOrigin origin)
{
switch (Cart.board_type)
{
case "MAPPER036":
AssertVram(0);
Cart.wram_size = 0; // AssertWram(0); // GoodNES good dump of Strike Wolf specifies 8kb of wram
break;
default:
return false;
}
chr_mask = Cart.chr_size / 8 - 1;
prg_mask = Cart.prg_size / 32 - 1;
SetMirrorType(Cart.pad_h, Cart.pad_v);
return true;
}
public override byte ReadPPU(int addr)
{
if (addr < 0x2000)
return VROM[addr | chr << 13];
else
return base.ReadPPU(addr);
}
public override byte ReadPRG(int addr)
{
return ROM[addr | prg << 15];
}
public override void WritePRG(int addr, byte value)
{
// either hack emulation of a weird bus conflict, or crappy pirate safeguard
prg = (R >> 4) & prg_mask;
}
public override byte ReadEXP(int addr)
{
return (byte)(R | (NES.DB & 0xCF));
}
public override void WriteEXP(int addr, byte value)
{
Console.WriteLine(addr);
Console.WriteLine(value);
if ((addr & 0xE200) == 0x200)
{
chr = value & 15 & chr_mask;
}
switch (addr & 0xE103)
{
case 0x100:
if (!M)
{
R = P;
}
else
{
R++;
R &= 0x30;
}
break;
case 0x102:
P = (byte)(value & 0x30);
prg = (value >> 4) & prg_mask;
break;
case 0x103:
M = value.Bit(4);
break;
}
}
public override void SyncState(Serializer ser)
{
base.SyncState(ser);
ser.Sync("chr", ref chr);
ser.Sync("prg", ref prg);
ser.Sync("R", ref R);
ser.Sync("M", ref M);
ser.Sync("P", ref P);
}
}
}