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Atari 2600 - DPC - do savestates, reset, disposing, and some small todos

This commit is contained in:
adelikat 2014-04-10 12:46:45 +00:00
parent 860483934f
commit c16e469e22
1 changed files with 60 additions and 40 deletions
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100
BizHawk.Emulation.Cores/Consoles/Atari/2600/Mappers/mDPC.cs
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@ -225,45 +225,69 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
*/
internal class mDPC : MapperBase
{
// TODO: HardReset
// TODO: Savestates
// TODO: Dispose
// TODO: sound channel doesn't work
private readonly IntBuffer _counters = new IntBuffer(8);
private readonly ByteBuffer _tops = new ByteBuffer(8);
private readonly ByteBuffer _flags = new ByteBuffer(8);
private readonly ByteBuffer _bottoms = new ByteBuffer(8);
private readonly bool[] _myMusicMode = new bool[3];
private IntBuffer _counters = new IntBuffer(8);
private ByteBuffer _tops = new ByteBuffer(8);
private ByteBuffer _flags = new ByteBuffer(8);
private ByteBuffer _bottoms = new ByteBuffer(8);
private bool[] _musicModes = new bool[3];
private int _bank4K;
private byte _myRandomNumber;
// TOD: something simpler here, don't need both
//private int _mySystemCycles;
private byte _currentRandomVal;
private int _elapsedCycles = 85; // 85 compensates for a slight timing issue when ClockCpu is first run, 85 puts BizHawk back on track with Stella on elapsed timing values
private float _fractionalClocks; // Fractional DPC music OSC clocks unused during the last update
// Fractional DPC music OSC clocks unused during the last update
private double _myFractionalClocks;
// TODO: refactor to not do this mess
private byte[] __mydisp;
private byte[] _myDisplayImage
private byte[] _dspData;
private byte[] DspData
{
get
{
return __mydisp ?? (__mydisp = Core.Rom.Skip(8192).Take(2048).ToArray());
return _dspData ?? (_dspData = Core.Rom.Skip(8192).Take(2048).ToArray());
}
}
// Table for computing the input bit of the random number generator's
// shift register (it's the NOT of the EOR of four bits)
private readonly byte[] _randomInputBits = { 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1 };
public override void Dispose()
{
base.Dispose();
_counters.Dispose();
_tops.Dispose();
_flags.Dispose();
_bottoms.Dispose();
}
public override void SyncState(Serializer ser)
{
base.SyncState(ser);
ser.Sync("counters", ref _counters);
ser.Sync("tops", ref _tops);
ser.Sync("flags", ref _flags);
ser.Sync("bottoms", ref _bottoms);
ser.Sync("musicMode0", ref _musicModes[0]); // Silly, but I didn't want to support bool[] in Serializer just for this one variable
ser.Sync("musicMode1", ref _musicModes[1]);
ser.Sync("musicMode2", ref _musicModes[2]);
ser.Sync("bank_4k", ref _bank4K);
ser.Sync("currentRandomVal", ref _currentRandomVal);
ser.Sync("elapsedCycles", ref _elapsedCycles);
ser.Sync("fractionalClocks", ref _fractionalClocks);
}
public override void HardReset()
{
_counters = new IntBuffer(8);
_tops = new ByteBuffer(8);
_flags = new ByteBuffer(8);
_bottoms = new ByteBuffer(8);
_musicModes = new bool[3];
_bank4K = 0;
_currentRandomVal = 0;
_elapsedCycles = 85;
_fractionalClocks = 0;
base.HardReset();
}
@ -308,7 +332,7 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
case 0x00:
if (index < 4)
{
result = _myRandomNumber;
result = _currentRandomVal;
}
else // No, it's a music read
{
@ -320,17 +344,17 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
UpdateMusicModeDataFetchers();
byte i = 0;
if (_myMusicMode[0] && _flags[5] > 0)
if (_musicModes[0] && _flags[5] > 0)
{
i |= 0x01;
}
if (_myMusicMode[1] && _flags[6] > 0)
if (_musicModes[1] && _flags[6] > 0)
{
i |= 0x02;
}
if (_myMusicMode[2] && _flags[7] > 0)
if (_musicModes[2] && _flags[7] > 0)
{
i |= 0x04;
}
@ -342,12 +366,12 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
// DFx display data read
case 0x01:
result = _myDisplayImage[2047 - _counters[index]];
result = DspData[2047 - _counters[index]];
break;
// DFx display data read AND'd w/flag
case 0x02:
result = (byte)(_myDisplayImage[2047 - _counters[index]] & _flags[index]);
result = (byte)(DspData[2047 - _counters[index]] & _flags[index]);
break;
// DFx flag
@ -361,7 +385,7 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
}
// Clock the selected data fetcher's counter if needed
if ((index < 5) || ((index >= 5) && (!_myMusicMode[index - 5])))
if ((index < 5) || ((index >= 5) && (!_musicModes[index - 5])))
{
_counters[index] = (_counters[index] - 1) & 0x07ff;
}
@ -413,7 +437,7 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
// DFx counter low
case 0x02:
if ((index >= 5) && _myMusicMode[index - 5])
if ((index >= 5) && _musicModes[index - 5])
{
// Data fetcher is in music mode so its low counter value
// should be loaded from the top register not the poked value
@ -438,7 +462,7 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
// Execute special code for music mode data fetchers
if (index >= 5)
{
_myMusicMode[index - 5] = (value & 0x10) > 0;
_musicModes[index - 5] = (value & 0x10) > 0;
// NOTE: We are not handling the clock source input for
// the music mode data fetchers. We're going to assume
@ -449,7 +473,7 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
// Random Number Generator Reset
case 0x06:
_myRandomNumber = 1;
_currentRandomVal = 1;
break;
}
}
@ -469,17 +493,13 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
private void ClockRandomNumberGenerator()
{
// Table for computing the input bit of the random number generator's
// shift register (it's the NOT of the EOR of four bits)
byte[] f = { 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1 };
// Using bits 7, 5, 4, & 3 of the shift register compute the input
// bit for the shift register
var bit = f[((_myRandomNumber >> 3) & 0x07) |
(((_myRandomNumber & 0x80) > 0) ? 0x08 : 0x00)];
var bit = _randomInputBits[((_currentRandomVal >> 3) & 0x07) |
(((_currentRandomVal & 0x80) > 0) ? 0x08 : 0x00)];
// Update the shift register
_myRandomNumber = (byte)((_myRandomNumber << 1) | bit);
_currentRandomVal = (byte)((_currentRandomVal << 1) | bit);
}
private void UpdateMusicModeDataFetchers()
@ -489,9 +509,9 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
_elapsedCycles = 0;
// Calculate the number of DPC OSC clocks since the last update
var clocks = ((20000.0 * cycles) / 1193191.66666667) + _myFractionalClocks;
var clocks = ((20000.0 * cycles) / 1193191.66666667) + _fractionalClocks;
var wholeClocks = (int)clocks;
_myFractionalClocks = clocks - wholeClocks;
_fractionalClocks = (float)(clocks - wholeClocks);
if (wholeClocks <= 0)
{
@ -502,7 +522,7 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
for (var x = 5; x <= 7; ++x)
{
// Update only if the data fetcher is in music mode
if (_myMusicMode[x - 5])
if (_musicModes[x - 5])
{
var top = _tops[x] + 1;
var newLow = _counters[x] & 0x00ff;