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BizHawk
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fds audio channel. completely untested

This commit is contained in:
goyuken 2012-10-22 16:10:19 +00:00
parent fbb46e7054
commit 966495cbae
3 changed files with 304 additions and 3 deletions
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1
BizHawk.Emulation/BizHawk.Emulation.csproj
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@ -269,6 +269,7 @@
<Compile Include="Consoles\Nintendo\NES\Boards\VsUnisys.cs" />
<Compile Include="Consoles\Nintendo\NES\Core.cs" />
<Compile Include="Consoles\Nintendo\NES\FDS\FDS.cs" />
<Compile Include="Consoles\Nintendo\NES\FDS\FDSAudio.cs" />
<Compile Include="Consoles\Nintendo\NES\FDS\RamAdapter.cs" />
<Compile Include="Consoles\Nintendo\NES\iNES.cs" />
<Compile Include="Consoles\Nintendo\NES\NES.cs" />

25
BizHawk.Emulation/Consoles/Nintendo/NES/FDS/FDS.cs
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@ -24,8 +24,9 @@ namespace BizHawk.Emulation.Consoles.Nintendo
/// </summary>
public byte[] diskimage;
RamAdapter diskdrive;
FDSAudio audio;
int audioclock;
// as we have [INESBoardImplCancel], this will only be called with an fds disk image
public override bool Configure(NES.EDetectionOrigin origin)
@ -40,6 +41,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
Cart.board_type = "FAMICOM_DISK_SYSTEM";
diskdrive = new RamAdapter();
audio = new FDSAudio();
InsertSide(0);
@ -89,9 +91,14 @@ namespace BizHawk.Emulation.Consoles.Nintendo
public override void WriteEXP(int addr, byte value)
{
Console.WriteLine("W{0:x4}:{1:x2} {2:x4}", addr + 0x4000, value, NES.cpu.PC);
if (addr >= 0x0040)
{
audio.WriteReg(addr + 0x4000, value);
return;
}
switch (addr)
{
case 0x0020:
@ -133,6 +140,9 @@ namespace BizHawk.Emulation.Consoles.Nintendo
{
byte ret = NES.DB;
if (addr >= 0x0040)
return audio.ReadReg(addr + 0x4000, ret);
switch (addr)
{
case 0x0030:
@ -194,6 +204,12 @@ namespace BizHawk.Emulation.Consoles.Nintendo
}
diskdrive.Clock();
diskirq = diskdrive.irq;
audioclock++;
if (audioclock == 3)
{
audioclock = 0;
audio.Clock();
}
}
public override byte ReadWRAM(int addr)
@ -220,6 +236,9 @@ namespace BizHawk.Emulation.Consoles.Nintendo
WRAM[addr + 0x2000] = value;
}
public override void ApplyCustomAudio(short[] samples)
{
audio.ApplyCustomAudio(samples);
}
}
}

281
BizHawk.Emulation/Consoles/Nintendo/NES/FDS/FDSAudio.cs Normal file
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@ -0,0 +1,281 @@
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace BizHawk.Emulation.Consoles.Nintendo
{
// http://wiki.nesdev.com/w/index.php/FDS_audio
public class FDSAudio
{
//4040:407f
byte[] waveram = new byte[64];
int waverampos;
//4080
int volumespd;
bool r4080_6;
bool r4080_7;
//4082:4083
int frequency;
bool r4083_6;
bool r4083_7;
//4084
int sweepspd;
bool r4084_6;
bool r4084_7;
//4085
int sweepbias;
//4086:4087
int modfreq;
bool r4087_7;
//4088
byte[] modtable = new byte[64];
int modtablepos;
//4089
int mastervol_num;
int mastervol_den;
bool waveram_writeenable;
//408a
int envspeed;
int volumeclock;
int sweepclock;
int modclock;
int mainclock;
int modoutput;
int volumegain;
int sweepgain;
int waveramoutput;
int latchedoutput;
/// <summary>
/// enough room to hold roughly one frame of final output, 0-2047
/// </summary>
short[] samplebuff = new short[32768];
int samplebuffpos = 0;
void CalcMod()
{
// really don't quite get this...
int tmp = sweepbias * sweepgain;
if ((tmp & 0xf) != 0)
{
tmp /= 16;
if (sweepbias < 0)
tmp -= 1;
else
tmp += 2;
}
else
tmp /= 16;
if (tmp > 193)
tmp -= 258;
else if (tmp < -64)
tmp += 256;
modoutput = frequency * tmp / 64;
}
void CalcOut()
{
int tmp = volumegain < 32 ? volumegain : 32;
tmp *= waveramoutput;
tmp *= mastervol_num;
tmp /= mastervol_den;
latchedoutput = tmp;
}
/// <summary>
/// ~1.7mhz
/// </summary>
public void Clock()
{
// volume envelope unit
if (!r4080_7 && envspeed > 0 && !r4080_6)
{
volumeclock++;
if (volumeclock >= 8 * envspeed * (volumespd + 1))
{
volumeclock = 0;
if (r4080_6 && volumegain < 32)
volumegain++;
else if (!r4080_6 && volumegain > 0)
volumegain--;
CalcOut();
}
}
// sweep unit
if (!r4084_7 && envspeed > 0 && !r4083_6)
{
sweepclock++;
if (sweepclock >= 8 * envspeed * (sweepspd + 1))
{
sweepclock = 0;
if (r4084_6 && sweepgain < 32)
sweepgain++;
else if (!r4084_6 && sweepgain > 0)
sweepgain--;
CalcMod();
}
}
// modulation unit
if (!r4087_7 && modfreq > 0)
{
modclock += modfreq;
if (modclock >= 0x10000)
{
modclock -= 0x10000;
// our modtable is really twice as big (64 entries)
switch (modtable[modtablepos++])
{
case 0: sweepbias += 0; break;
case 1: sweepbias += 1; break;
case 2: sweepbias += 2; break;
case 3: sweepbias += 4; break;
case 4: sweepbias = 0; break;
case 5: sweepbias -= 4; break;
case 6: sweepbias -= 2; break;
case 7: sweepbias -= 1; break;
}
sweepbias &= 0x7f;
modtablepos &= 63;
CalcMod();
}
}
// main unit
if (!r4083_7 && frequency > 0 && frequency + modoutput > 0 && !waveram_writeenable)
{
mainclock += frequency + modoutput;
if (mainclock >= 0x10000)
{
mainclock -= 0x10000;
waveramoutput = waveram[waverampos++];
waverampos &= 63;
CalcOut();
}
}
samplebuff[samplebuffpos++] = (short)latchedoutput;
// if for some reason ApplyCustomAudio() is not called, glitch up but don't crash
samplebuffpos &= 32767;
}
public void WriteReg(int addr, byte value)
{
if (addr < 0x4080)
{
if (waveram_writeenable)
// can waverampos ever be reset?
waveram[addr - 0x4040] = (byte)(value & 63);
return;
}
switch (addr)
{
case 0x4080:
r4080_6 = (value & 0x40) != 0;
r4080_7 = (value & 0x80) != 0;
if (r4080_7) // envelope is off, so written value gets sent to gain directly
volumegain = value & 63;
else // envelope is on; written value is speed of change
volumespd = value & 63;
break;
case 0x4082:
frequency &= 0xf00;
frequency |= value;
break;
case 0x4083:
frequency &= 0x0ff;
frequency |= value << 8 & 0xf00;
r4083_6 = (value & 0x40) != 0;
r4083_7 = (value & 0x80) != 0;
break;
case 0x4084:
sweepspd = value & 63;
r4084_6 = (value & 0x40) != 0;
r4084_7 = (value & 0x80) != 0;
break;
case 0x4085:
modtablepos = 0; // reset
sweepbias = value & 0x7f;
// sign extend
sweepbias <<= 25;
sweepbias >>= 25;
break;
case 0x4086:
modfreq &= 0xf00;
modfreq |= value;
if (r4087_7 || modfreq == 0) // when mod unit is disabled, mod output is fixed to 0, not hanging
modoutput = 0;
break;
case 0x4087:
modfreq &= 0x0ff;
modfreq |= value << 8 & 0xf00;
r4087_7 = (value & 0x80) != 0;
if (r4087_7 || modfreq == 0) // when mod unit is disabled, mod output is fixed to 0, not hanging
modoutput = 0;
break;
case 0x4088:
// write twice into virtual 64 unit buffer
Buffer.BlockCopy(modtable, 2, modtable, 0, 62);
modtable[62] = (byte)(value & 7);
modtable[63] = (byte)(value & 7);
break;
case 0x4089:
switch (value & 3)
{
case 0: mastervol_num = 1; mastervol_den = 1; break;
case 1: mastervol_num = 2; mastervol_den = 3; break;
case 2: mastervol_num = 2; mastervol_den = 4; break;
case 3: mastervol_num = 2; mastervol_den = 5; break;
}
waveram_writeenable = (value & 0x80) != 0;
break;
case 0x408a:
envspeed = value;
break;
}
}
public byte ReadReg(int addr, byte openbus)
{
byte ret = openbus;
if (addr < 0x4080)
{
ret &= 0xc0;
ret |= waveram[addr - 0x4040];
}
else if (addr == 0x4090)
{
ret &= 0xc0;
ret |= (byte)volumegain;
}
else if (addr == 0x4092)
{
ret &= 0xc0;
ret |= (byte)sweepgain;
}
return ret;
}
public void ApplyCustomAudio(short[] samples)
{
for (int i = 0; i < samples.Length; i += 2)
{
int pos = i * samplebuffpos / samples.Length;
short samp = (short)(samplebuff[pos] * 20 - 20160);
// nothing for clipping, and the worst imaginable resampling
samples[i] += samp;
samples[i + 1] += samp;
}
Console.WriteLine("##{0}##", samplebuffpos);
samplebuffpos = 0;
}
}
}