Path: blob/master/BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.Core.cs
2 views
using System;
using BizHawk.Common;
using BizHawk.Common.NumberExtensions;
using BizHawk.Common.BufferExtensions;
using BizHawk.Emulation.Common;
using BizHawk.Emulation.Cores.Components.M6502;
namespace BizHawk.Emulation.Cores.Atari.Atari2600
{
public partial class Atari2600
{
private TIA _tia;
private DCFilter _dcfilter;
private MapperBase _mapper;
internal byte[] Ram;
internal byte[] Rom { get; private set; }
internal MOS6502X Cpu { get; private set; }
internal M6532 M6532 { get; private set; }
internal int LastAddress;
internal int DistinctAccessCount;
private bool _frameStartPending = true;
private bool _leftDifficultySwitchPressed = false;
private bool _rightDifficultySwitchPressed = false;
private bool _leftDifficultySwitchHeld = false;
private bool _rightDifficultySwitchHeld = false;
internal byte BaseReadMemory(ushort addr)
{
addr = (ushort)(addr & 0x1FFF);
if ((addr & 0x1080) == 0)
{
return _tia.ReadMemory(addr, false);
}
if ((addr & 0x1080) == 0x0080)
{
_tia.bus_state = M6532.ReadMemory(addr, false);
return M6532.ReadMemory(addr, false);
}
_tia.bus_state = Rom[addr & 0x0FFF];
return Rom[addr & 0x0FFF];
}
internal byte BasePeekMemory(ushort addr)
{
addr = (ushort)(addr & 0x1FFF);
if ((addr & 0x1080) == 0)
{
return _tia.ReadMemory(addr, true);
}
if ((addr & 0x1080) == 0x0080)
{
return M6532.ReadMemory(addr, true);
}
return Rom[addr & 0x0FFF];
}
internal void BaseWriteMemory(ushort addr, byte value)
{
_tia.bus_state = value;
if (addr != LastAddress)
{
DistinctAccessCount++;
LastAddress = addr;
}
addr = (ushort)(addr & 0x1FFF);
if ((addr & 0x1080) == 0)
{
_tia.WriteMemory(addr, value, false);
}
else if ((addr & 0x1080) == 0x0080)
{
M6532.WriteMemory(addr, value);
}
else
{
Console.WriteLine("ROM write(?): " + addr.ToString("x"));
}
}
internal void BasePokeMemory(ushort addr, byte value)
{
addr = (ushort)(addr & 0x1FFF);
if ((addr & 0x1080) == 0)
{
_tia.WriteMemory(addr, value, true);
}
else if ((addr & 0x1080) == 0x0080)
{
M6532.WriteMemory(addr, value);
}
else
{
Console.WriteLine("ROM write(?): " + addr.ToString("x"));
}
}
internal byte ReadMemory(ushort addr)
{
if (addr != LastAddress)
{
DistinctAccessCount++;
LastAddress = addr;
}
_mapper.Bit13 = addr.Bit(13);
var temp = _mapper.ReadMemory((ushort)(addr & 0x1FFF));
_tia.bus_state = temp;
MemoryCallbacks.CallReads(addr);
return temp;
}
internal byte PeekMemory(ushort addr)
{
var temp = _mapper.PeekMemory((ushort)(addr & 0x1FFF));
return temp;
}
internal void WriteMemory(ushort addr, byte value)
{
if (addr != LastAddress)
{
DistinctAccessCount++;
LastAddress = addr;
}
_mapper.WriteMemory((ushort)(addr & 0x1FFF), value);
MemoryCallbacks.CallWrites(addr);
}
internal void PokeMemory(ushort addr, byte value)
{
_mapper.PokeMemory((ushort)(addr & 0x1FFF), value);
}
private void ExecFetch(ushort addr)
{
MemoryCallbacks.CallExecutes(addr);
}
private static MapperBase SetMultiCartMapper(int romLength, int gameTotal)
{
switch (romLength / gameTotal)
{
case 1024 * 2: // 2K
return new Multicart2K(gameTotal);
default:
case 1024 * 4: // 4K
return new Multicart4K(gameTotal);
case 1024 * 8: // 8K
return new Multicart8K(gameTotal);
}
}
private void RebootCore()
{
// Regenerate mapper here to make sure its state is entirely clean
switch (_game.GetOptionsDict()["m"])
{
case "2IN1":
_mapper = SetMultiCartMapper(Rom.Length, 2);
break;
case "4IN1":
_mapper = SetMultiCartMapper(Rom.Length, 4);
break;
case "8IN1":
_mapper = SetMultiCartMapper(Rom.Length, 8);
break;
case "16IN1":
_mapper = SetMultiCartMapper(Rom.Length, 16);
break;
case "32IN1":
_mapper = SetMultiCartMapper(Rom.Length, 32);
break;
case "AR":
_mapper = new mAR(this); // This mapper has to set up configurations in the contructor.
break;
case "4K":
_mapper = new m4K();
break;
case "2K":
_mapper = new m2K();
break;
case "CM":
_mapper = new mCM();
break;
case "CV":
_mapper = new mCV();
break;
case "DPC":
_mapper = new mDPC();
break;
case "DPC+":
_mapper = new mDPCPlus();
break;
case "F8":
_mapper = new mF8();
break;
case "F8SC":
_mapper = new mF8SC();
break;
case "F6":
_mapper = new mF6();
break;
case "F6SC":
_mapper = new mF6SC();
break;
case "F4":
_mapper = new mF4();
break;
case "F4SC":
_mapper = new mF4SC();
break;
case "FE":
_mapper = new mFE();
break;
case "E0":
_mapper = new mE0();
break;
case "3F":
_mapper = new m3F();
break;
case "FA":
_mapper = new mFA();
break;
case "FA2":
_mapper = new mFA2();
break;
case "E7":
_mapper = new mE7();
break;
case "F0":
_mapper = new mF0();
break;
case "UA":
_mapper = new mUA();
break;
// Special Sega Mapper which has swapped banks
case "F8_sega":
_mapper = new mF8_sega();
break;
// Homebrew mappers
case "3E":
_mapper = new m3E();
break;
case "0840":
_mapper = new m0840();
break;
case "MC":
_mapper = new mMC();
break;
case "EF":
_mapper = new mEF();
break;
case "EFSC":
_mapper = new mEFSC();
break;
case "X07":
_mapper = new mX07();
break;
case "4A50":
_mapper = new m4A50();
break;
case "SB":
_mapper = new mSB();
break;
default:
throw new InvalidOperationException("mapper not supported: " + _game.GetOptionsDict()["m"]);
}
_mapper.Core = this;
_lagcount = 0;
Cpu = new MOS6502X
{
ReadMemory = this.ReadMemory,
WriteMemory = this.WriteMemory,
PeekMemory = this.PeekMemory,
DummyReadMemory = this.ReadMemory,
OnExecFetch = this.ExecFetch
};
if (_game["PAL"])
{
_pal = true;
}
else if (_game["NTSC"])
{
_pal = false;
}
else
{
_pal = DetectPal(_game, Rom);
}
// dcfilter coefficent is from real observed hardware behavior: a latched "1" will fully decay by ~170 or so tia sound cycles
_tia = new TIA(this, _pal, Settings.SECAMColors, CoreComm.VsyncRate > 55.0 ? 735 : 882);
_tia.GetFrameRate(out CoreComm.VsyncNum, out CoreComm.VsyncDen);
_dcfilter = new DCFilter(_tia, 256);
M6532 = new M6532(this);
// Set up the system state here. for instance..
// Read from the reset vector for where to start
Cpu.PC = (ushort)(ReadMemory(0x1FFC) + (ReadMemory(0x1FFD) << 8)); // set the initial PC
// Show mapper class on romstatusdetails
CoreComm.RomStatusDetails =
string.Format(
"{0}\r\nSHA1:{1}\r\nMD5:{2}\r\nMapper Impl \"{3}\"",
this._game.Name,
Rom.HashSHA1(),
Rom.HashMD5(),
_mapper.GetType());
// as it turns out, the stack pointer cannot be set to 0 for some games as they do not initilize it themselves.
// some documentation seems to indicate it should beset to FD, but currently there is no documentation of the 6532
// executing a reset sequence at power on, but it's needed so let's hard code it for now
Cpu.S = 0xFD;
}
private bool _pal;
private void HardReset()
{
Ram = new byte[128];
_mapper.HardReset();
Cpu = new MOS6502X
{
ReadMemory = this.ReadMemory,
WriteMemory = this.WriteMemory,
PeekMemory = this.PeekMemory,
DummyReadMemory = this.ReadMemory,
OnExecFetch = this.ExecFetch
};
_tia.Reset();
M6532 = new M6532(this);
Cpu.PC = (ushort)(ReadMemory(0x1FFC) + (ReadMemory(0x1FFD) << 8)); // set the initial PC
// as it turns out, the stack pointer cannot be set to 0 for some games as they do not initilize it themselves.
// some documentation seems to indicate it should beset to FD, but currently there is no documentation of the 6532
// executing a reset sequence at power on, but it's needed so let's hard code it for now
Cpu.S = 0xFD;
}
public void FrameAdvance(bool render, bool rendersound)
{
StartFrameCond();
while (_tia.LineCount < _tia.NominalNumScanlines)
Cycle();
if (rendersound==false)
_tia._audioClocks = 0; // we need this here since the async sound provider won't check in this case
FinishFrameCond();
}
private void VFrameAdvance() // advance up to 500 lines looking for end of video frame
// after vsync falling edge, continues to end of next line
{
bool frameend = false;
_tia.FrameEndCallBack = (n) => frameend = true;
for (int i = 0; i < 500 && !frameend; i++)
ScanlineAdvance();
_tia.FrameEndCallBack = null;
}
private void StartFrameCond()
{
if (_frameStartPending)
{
_frame++;
_islag = true;
if (Controller.IsPressed("Power"))
{
HardReset();
}
if (Controller.IsPressed("Toggle Left Difficulty") && !_leftDifficultySwitchHeld)
{
_leftDifficultySwitchPressed ^= true;
_leftDifficultySwitchHeld = true;
}
else if (!Controller.IsPressed("Toggle Left Difficulty"))
{
_leftDifficultySwitchHeld = false;
}
if (Controller.IsPressed("Toggle Right Difficulty") && !_rightDifficultySwitchHeld)
{
_rightDifficultySwitchPressed ^= true;
_rightDifficultySwitchHeld = true;
}
else if (!Controller.IsPressed("Toggle Right Difficulty"))
{
_rightDifficultySwitchHeld = false;
}
_tia.BeginAudioFrame();
_frameStartPending = false;
}
}
private void FinishFrameCond()
{
if (_tia.LineCount >= _tia.NominalNumScanlines)
{
_tia.CompleteAudioFrame();
if (_islag)
_lagcount++;
_tia.LineCount = 0;
_frameStartPending = true;
}
}
private void Cycle()
{
_tia.Execute(1);
_tia.Execute(1);
_tia.Execute(1);
M6532.Timer.Tick();
if (Tracer.Enabled)
{
Tracer.Put(Cpu.TraceState());
}
Cpu.ExecuteOne();
_mapper.ClockCpu();
}
internal byte ReadControls1(bool peek)
{
InputCallbacks.Call();
byte value = 0xFF;
if (Controller.IsPressed("P1 Up")) { value &= 0xEF; }
if (Controller.IsPressed("P1 Down")) { value &= 0xDF; }
if (Controller.IsPressed("P1 Left")) { value &= 0xBF; }
if (Controller.IsPressed("P1 Right")) { value &= 0x7F; }
if (Controller.IsPressed("P1 Button")) { value &= 0xF7; }
if (!peek)
{
_islag = false;
}
return value;
}
internal byte ReadControls2(bool peek)
{
InputCallbacks.Call();
byte value = 0xFF;
if (Controller.IsPressed("P2 Up")) { value &= 0xEF; }
if (Controller.IsPressed("P2 Down")) { value &= 0xDF; }
if (Controller.IsPressed("P2 Left")) { value &= 0xBF; }
if (Controller.IsPressed("P2 Right")) { value &= 0x7F; }
if (Controller.IsPressed("P2 Button")) { value &= 0xF7; }
if (!peek)
{
_islag = false;
}
return value;
}
internal byte ReadConsoleSwitches(bool peek)
{
byte value = 0xFF;
bool select = Controller.IsPressed("Select");
bool reset = Controller.IsPressed("Reset");
if (reset) { value &= 0xFE; }
if (select) { value &= 0xFD; }
if (SyncSettings.BW) { value &= 0xF7; }
if (_leftDifficultySwitchPressed)
{
value &= 0xBF;
}
if (_rightDifficultySwitchPressed)
{
value &= 0x7F;
}
if (!peek)
{
_islag = false;
}
return value;
}
}
}