BizHawk/BizHawk.Emulation.Cores/Consoles/Atari/2600/Mappers/Multicart8K.cs

106 lines
1.8 KiB
C#

using System.Linq;
using BizHawk.Common;
namespace BizHawk.Emulation.Cores.Atari.Atari2600
{
/*
Mapper used for multi-cart 8K games
*/
internal class Multicart8K : MapperBase
{
private int _bank4K;
private int _gameTotal;
private int _currentGame;
public Multicart8K(int gametotal)
{
_gameTotal = gametotal;
_currentGame = 0;
}
public override void SyncState(Serializer ser)
{
ser.Sync("bank_4k", ref _bank4K);
ser.Sync("gameTotal", ref _gameTotal);
ser.Sync("currentGame", ref _currentGame);
base.SyncState(ser);
}
public override void HardReset()
{
_bank4K = 0;
IncrementGame();
}
private void IncrementGame()
{
_currentGame++;
if (_currentGame >= _gameTotal)
{
_currentGame = 0;
}
}
private byte ReadMem(ushort addr, bool peek)
{
if (!peek)
{
Address(addr);
}
if (addr < 0x1000)
{
return base.ReadMemory(addr);
}
return Core.Rom[(_bank4K << 12) + (addr & 0xFFF) + (_currentGame * 8192)];
}
public override byte ReadMemory(ushort addr)
{
return ReadMem(addr, false);
}
public override byte PeekMemory(ushort addr)
{
return ReadMem(addr, true);
}
private void WriteMem(ushort addr, byte value, bool poke)
{
if (!poke)
{
Address(addr);
}
if (addr < 0x1000)
{
base.WriteMemory(addr, value);
}
}
public override void WriteMemory(ushort addr, byte value)
{
WriteMem(addr, value, poke: false);
}
public override void PokeMemory(ushort addr, byte value)
{
WriteMem(addr, value, poke: true);
}
private void Address(ushort addr)
{
if (addr == 0x1FF8)
{
_bank4K = 0;
}
else if (addr == 0x1FF9)
{
_bank4K = 1;
}
}
}
}