92 lines
1.6 KiB
C#
92 lines
1.6 KiB
C#
using BizHawk.Common;
|
|
|
|
namespace BizHawk.Emulation.Cores.Atari.Atari2600
|
|
{
|
|
/*
|
|
UA (UA Ltd)
|
|
-----
|
|
|
|
This one was found out later on, lurking on a proto of Pleaides. It works with 8K of ROM
|
|
and banks it in 4K at a time.
|
|
|
|
Accessing 0220 will select the first bank, and accessing 0240 will select the second.
|
|
*/
|
|
|
|
internal class mUA : MapperBase
|
|
{
|
|
private int _toggle;
|
|
|
|
public override void SyncState(Serializer ser)
|
|
{
|
|
base.SyncState(ser);
|
|
ser.Sync("toggle", ref _toggle);
|
|
}
|
|
|
|
public override void HardReset()
|
|
{
|
|
_toggle = 0;
|
|
base.HardReset();
|
|
}
|
|
|
|
private byte ReadMem(ushort addr, bool peek)
|
|
{
|
|
if (!peek)
|
|
{
|
|
Address(addr);
|
|
}
|
|
|
|
if (addr < 0x1000)
|
|
{
|
|
return base.ReadMemory(addr);
|
|
}
|
|
|
|
return Core.Rom[(_toggle << 12) + (addr & 0xFFF)];
|
|
}
|
|
|
|
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 == 0x0220)
|
|
{
|
|
_toggle = 0;
|
|
}
|
|
else if (addr == 0x0240)
|
|
{
|
|
_toggle = 1;
|
|
}
|
|
}
|
|
}
|
|
}
|