86 lines
1.9 KiB
C#
86 lines
1.9 KiB
C#
using BizHawk.Common;
|
|
|
|
namespace BizHawk.Emulation.Cores.Atari.Atari2600
|
|
{
|
|
/*
|
|
EF (no name?)
|
|
-----
|
|
|
|
This is a fairly simple method that allows for up to 64K of ROM, using 16 4K banks.
|
|
It works similar to F8, F6, etc. Only the addresses to perform the switch is
|
|
1FE0-1FEF. Accessing one of these will select the desired bank. 1FE0 = bank 0,
|
|
1FE1 = bank 1, etc.
|
|
*/
|
|
|
|
internal class mEF : 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);
|
|
}
|
|
|
|
public override void WriteMemory(ushort addr, byte value)
|
|
{
|
|
Address(addr);
|
|
if (addr < 0x1000)
|
|
{
|
|
base.WriteMemory(addr, value);
|
|
}
|
|
}
|
|
|
|
private void Address(ushort addr)
|
|
{
|
|
if (addr == 0x1FE0) _toggle = 0;
|
|
if (addr == 0x1FE1) _toggle = 1;
|
|
if (addr == 0x1FE2) _toggle = 2;
|
|
if (addr == 0x1FE3) _toggle = 3;
|
|
if (addr == 0x1FE4) _toggle = 4;
|
|
if (addr == 0x1FE5) _toggle = 5;
|
|
if (addr == 0x1FE6) _toggle = 6;
|
|
if (addr == 0x1FE7) _toggle = 7;
|
|
if (addr == 0x1FE8) _toggle = 8;
|
|
if (addr == 0x1FE9) _toggle = 9;
|
|
if (addr == 0x1FEA) _toggle = 10;
|
|
if (addr == 0x1FEB) _toggle = 11;
|
|
if (addr == 0x1FEC) _toggle = 12;
|
|
if (addr == 0x1FED) _toggle = 13;
|
|
if (addr == 0x1FEE) _toggle = 14;
|
|
if (addr == 0x1FEF) _toggle = 15;
|
|
}
|
|
}
|
|
}
|