ShuriZma
/
BizHawk
mirror of https://github.com/TASEmulators/BizHawk.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Atari 2600 - Implement mapper EFSC

This commit is contained in:
adelikat 2014-04-05 00:35:08 +00:00
parent 842645b9ab
commit cf1a50c195
1 changed files with 77 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

80
BizHawk.Emulation.Cores/Consoles/Atari/2600/Mappers/mEFSC.cs
View File

@ -1,4 +1,4 @@
using System;
using BizHawk.Common;
namespace BizHawk.Emulation.Cores.Atari.Atari2600
{
@ -9,9 +9,83 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
*/
internal class mEFSC : MapperBase
{
public mEFSC()
private int _bank4k;
private ByteBuffer _ram = new ByteBuffer(128);
private byte ReadMem(ushort addr, bool peek)
{
throw new NotImplementedException();
if (!peek)
{
Address(addr);
}
if (addr < 0x1000)
{
return base.ReadMemory(addr);
}
if (addr < 0x1080)
{
_ram[(addr & 0x7F)] = 0xFF; // Reading from the write port triggers an unwanted write of open bus
return 0xFF; // 0xFF is used for deterministic emulation, in reality it would be a random value based on pins being high or low
}
else if (addr < 0x1100)
{
return _ram[(addr & 0x7F)];
}
return core.rom[(_bank4k << 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);
}
else if ((addr & 0x0FFF) < 0x80)
{
_ram[addr & 0x7F] = value;
}
}
public override void SyncState(Serializer ser)
{
base.SyncState(ser);
ser.Sync("bank4k", ref _bank4k);
ser.Sync("auxRam", ref _ram);
}
private void Address(ushort addr)
{
if (addr == 0x1FE0) _bank4k = 0;
if (addr == 0x1FE1) _bank4k = 1;
if (addr == 0x1FE2) _bank4k = 2;
if (addr == 0x1FE3) _bank4k = 3;
if (addr == 0x1FE4) _bank4k = 4;
if (addr == 0x1FE5) _bank4k = 5;
if (addr == 0x1FE6) _bank4k = 6;
if (addr == 0x1FE7) _bank4k = 7;
if (addr == 0x1FE8) _bank4k = 8;
if (addr == 0x1FE9) _bank4k = 9;
if (addr == 0x1FEA) _bank4k = 10;
if (addr == 0x1FEB) _bank4k = 11;
if (addr == 0x1FEC) _bank4k = 12;
if (addr == 0x1FED) _bank4k = 13;
if (addr == 0x1FEE) _bank4k = 14;
if (addr == 0x1FEF) _bank4k = 15;
}
}
}