working on z80 sound worker

index.html

@@ -214,6 +214,7 @@ div.bitmap_editor {
             <li><a class="dropdown-item" href="?platform=galaxian-scramble" id="item_platform_galaxian_scramble">Galaxian/Scramble</a></li>
             <li><a class="dropdown-item" href="?platform=vector-z80color" id="item_platform_vector_z80color">Atari Color Vector (Z80)</a></li>
             <li><a class="dropdown-item" href="?platform=williams-z80" id="item_platform_williams_z80">Williams (Z80)</a></li>
+            <li><a class="dropdown-item" href="?platform=sound_williams-z80" id="item_platform_sound_williams_z80">Williams Sound (Z80)</a></li>
           </ul>
       </li>
       <li class="dropdown dropdown-submenu">
@@ -315,6 +316,7 @@ Dest: $<span id="bitmap_editor_dest">0000/0</span>
 <script src="octokat.js/dist/octokat.js"></script>
 
 <script src="src/emu.js"></script>
+<script src="src/audio.js"></script>
 <script src="src/util.js"></script>
 <script src="src/disasm.js"></script>
 <script src="src/ui.js"></script>

presets/sound_williams-z80/minimal.c

@@ -0,0 +1,17 @@
+
+const __sfr __at (0x0) command;
+__sfr __at (0x0) dac;
+
+#define HALT __asm halt __endasm;
+
+// press "2" or higher to activate...
+
+void main() {
+  char i;
+  char j;
+  if (command == 0) HALT;
+  for (i=0; i<255; i++) {
+    for (j=0; j<i; j++) dac=j^i;
+  }
+  HALT;
+}

presets/sound_williams-z80/skeleton.sdcc

@@ -0,0 +1,17 @@
+
+const __sfr __at (0x0) command;
+__sfr __at (0x0) dac;
+
+#define HALT __asm halt __endasm;
+
+// press "2" or higher to activate...
+
+void main() {
+  char i;
+  char j;
+  if (command == 0) HALT;
+  for (i=0; i<255; i++) {
+    for (j=0; j<i; j++) dac=j^i;
+  }
+  HALT;
+}

src/audio.js

@@ -0,0 +1,306 @@
+"use strict";
+
+var MasterAudio = function() {
+  this.master = new MasterChannel();
+  this.start = function() {
+    this.looper = new AudioLooper(512);
+    this.looper.setChannel(this.master);
+    this.looper.activate();
+  }
+  this.stop = function() {
+    this.looper.setChannel(null);
+  }
+}
+
+var AY38910_Audio = function(master) {
+  this.psg = new PsgDeviceChannel();
+  this.psg.setMode(PsgDeviceChannel.MODE_SIGNED);
+  this.psg.setDevice(PsgDeviceChannel.DEVICE_AY_3_8910);
+  master.master.addChannel(this.psg);
+  var curreg = 0;
+
+  this.reset = function() {
+    for (var i=15; i>=0; i--) {
+      this.selectRegister(i);
+      this.setData(0);
+    }
+  }
+  this.selectRegister = function(val) {
+    curreg = val & 0xf;
+  }
+  this.setData = function(val) {
+    this.psg.writeRegisterAY(curreg, val & 0xff);
+  }
+}
+
+// https://en.wikipedia.org/wiki/POKEY
+// https://user.xmission.com/~trevin/atari/pokey_regs.html
+// http://krap.pl/mirrorz/atari/homepage.ntlworld.com/kryten_droid/Atari/800XL/atari_hw/pokey.htm
+
+var POKEYDeviceChannel = function() {
+
+  /* definitions for AUDCx (D201, D203, D205, D207) */
+  var NOTPOLY5    = 0x80     /* selects POLY5 or direct CLOCK */
+  var POLY4       = 0x40     /* selects POLY4 or POLY17 */
+  var PURE        = 0x20     /* selects POLY4/17 or PURE tone */
+  var VOL_ONLY    = 0x10     /* selects VOLUME OUTPUT ONLY */
+  var VOLUME_MASK = 0x0f     /* volume mask */
+
+  /* definitions for AUDCTL (D208) */
+  var POLY9       = 0x80     /* selects POLY9 or POLY17 */
+  var CH1_179     = 0x40     /* selects 1.78979 MHz for Ch 1 */
+  var CH3_179     = 0x20     /* selects 1.78979 MHz for Ch 3 */
+  var CH1_CH2     = 0x10     /* clocks channel 1 w/channel 2 */
+  var CH3_CH4     = 0x08     /* clocks channel 3 w/channel 4 */
+  var CH1_FILTER  = 0x04     /* selects channel 1 high pass filter */
+  var CH2_FILTER  = 0x02     /* selects channel 2 high pass filter */
+  var CLOCK_15    = 0x01     /* selects 15.6999kHz or 63.9210kHz */
+
+  /* for accuracy, the 64kHz and 15kHz clocks are exact divisions of
+     the 1.79MHz clock */
+  var DIV_64      = 28       /* divisor for 1.79MHz clock to 64 kHz */
+  var DIV_15      = 114      /* divisor for 1.79MHz clock to 15 kHz */
+
+  /* the size (in entries) of the 4 polynomial tables */
+  var POLY4_SIZE  = 0x000f
+  var POLY5_SIZE  = 0x001f
+  var POLY9_SIZE  = 0x01ff
+
+  var POLY17_SIZE = 0x0001ffff    /* else use the full 17 bits */
+
+  /* channel/chip definitions */
+  var CHAN1       = 0
+  var CHAN2       = 1
+  var CHAN3       = 2
+  var CHAN4       = 3
+  var CHIP1       = 0
+  var CHIP2       = 4
+  var CHIP3       = 8
+  var CHIP4       = 12
+  var SAMPLE      = 127
+
+  var FREQ_17_EXACT     = 1789790.0  /* exact 1.79 MHz clock freq */
+  var FREQ_17_APPROX    = 1787520.0  /* approximate 1.79 MHz clock freq */
+
+  // LFSR sequences
+  var bit1 = [ 0,1 ];
+  var bit4 = [ 1,1,0,1,1,1,0,0,0,0,1,0,1,0,0 ];
+  var bit5 = [ 0,0,1,1,0,0,0,1,1,1,1,0,0,1,0,1,0,1,1,0,1,1,1,0,1,0,0,0,0,0,1 ];
+  var bit17 = new Uint8Array(1<<17);
+  var bit17_5 = new Uint8Array(1<<17);
+  var bit5_4 = new Uint8Array(1<<17);
+  for (var i=0; i<bit17.length; i++) {
+    bit17[i] = Math.random() > 0.5;
+    bit17_5[i] = bit17[i] & bit5[i % bit5.length];
+    bit5_4[i] = bit5[i % bit5.length] & bit4[i % bit4.length];
+  }
+  var wavetones = [
+    bit17_5, bit5, bit5_4, bit5,
+    bit17, bit1, bit4, bit1
+  ];
+
+  // registers
+  var regs = new Uint8Array(16);
+  var counters = new Float32Array(4);
+  var deltas = new Float32Array(4);
+  var volume = new Float32Array(4);
+  var audc = new Uint8Array(4);
+  var waveforms = [bit1, bit1, bit1, bit1];
+  var buffer;
+  var sampleRate;
+  var clock, baseDelta;
+  var dirty = true;
+
+  //
+
+  this.setBufferLength = function (length) {
+    buffer = new Int32Array(length);
+  };
+
+  this.getBuffer = function () {
+    return buffer;
+  };
+
+  this.setSampleRate = function (rate) {
+    sampleRate = rate;
+    baseDelta = FREQ_17_EXACT / rate / 1.2; // TODO?
+  };
+
+  function updateValues(addr) {
+    var ctrl = regs[8];
+    var base = (ctrl & CLOCK_15) ? DIV_15 : DIV_64;
+    var div;
+    var i = addr & 4;
+    var j = i>>1;
+    var k = i>>2;
+    if (ctrl & (CH1_CH2>>k)) {
+      if (ctrl & (CH1_179>>k))
+         div = regs[i+2] * 256 + regs[i+0] + 7;
+      else
+         div = (regs[i+2] * 256 + regs[i+0] + 1) * base;
+      deltas[j+1] = baseDelta / div;
+      deltas[j+0] = 0;
+    } else {
+      if (ctrl & (CH1_179>>k)) {
+        div = regs[i+0] + 4;
+      } else {
+        div = (regs[i+0] + 1) * base;
+      }
+      deltas[j+0] = baseDelta / div;
+      div = (regs[i+2] + 1) * base;
+      deltas[j+1] = baseDelta / div;
+    }
+    //console.log(addr, ctrl.toString(16), div, deltas[j+0], deltas[j+1]);
+  }
+
+  this.setRegister = function(addr, value) {
+    addr &= 0xf;
+    value &= 0xff;
+    if (regs[addr] != value) {
+      regs[addr] = value;
+      switch (addr) {
+        case 0:
+        case 2:
+        case 4:
+        case 6: // AUDF
+        case 8: // ctrl
+          dirty = true;
+          break;
+        case 1:
+        case 3:
+        case 5:
+        case 7: // AUDC
+          volume[addr>>1] = value & 0xf;
+          waveforms[addr>>1] = wavetones[value>>5];
+          break;
+      }
+    }
+  }
+
+  this.generate = function (length) {
+    if (dirty) {
+      updateValues(0);
+      updateValues(4);
+      dirty = false;
+    }
+    for (var s=0; s<length; s+=2) {
+      var sample = 0;
+      for (var i=0; i<4; i++) {
+        var d = deltas[i];
+        var v = volume[i];
+        if (d > 0 && d < 1 && v > 0) {
+          var wav = waveforms[i];
+          var cnt = counters[i] += d;
+          if (cnt > POLY17_SIZE+1) {
+            counters[i] -= POLY17_SIZE+1;
+          }
+          var on = wav[Math.floor(cnt % wav.length)];
+          if (on) {
+            sample += v;
+          }
+        }
+      }
+      sample *= 273;
+      buffer[s] = sample;
+      buffer[s+1] = sample;
+    }
+  }
+}
+
+////// CPU sound (unused)
+
+var CPUSoundChannel = function(cpu, clockRate) {
+  var sampleRate;
+  var buffer;
+  var lastbufpos=0;
+  var curSample=0;
+  var clocksPerSample;
+
+  this.setBufferLength = function (length) {
+    buffer = new Int32Array(length);
+  };
+
+  this.getBuffer = function () {
+    return buffer;
+  };
+
+  this.setSampleRate = function (rate) {
+    sampleRate = rate;
+  };
+
+  this.getSetDACFunction = function() {
+    return function(a,v) {
+      var bufpos = Math.floor(cpu.getTstates() / clocksPerSample);
+      while (lastbufpos < bufpos)
+        buffer[lastbufpos++] = curSample;
+      lastbufpos = bufpos;
+      curSample = v;
+    };
+  };
+
+  this.generate = function (length) {
+    clocksPerSample = clockRate * 1.0 / sampleRate;
+    var clocks = Math.round(length * clocksPerSample);
+    if (cpu.getTstates && cpu.runFrame) {
+      cpu.setTstates(0);
+      lastbufpos = 0;
+      cpu.runFrame(cpu.getTstates() + totalClocks);
+      while (lastbufpos < length)
+        buffer[lastbufpos++] = curSample;
+    }
+  };
+}
+
+////// Worker sound
+
+var WorkerSoundChannel = function(worker) {
+  var sampleRate;
+  var output;
+  var pending = [];
+  var pendingLength = 0;
+
+  worker.onmessage = function(e) {
+    if (e && e.data && e.data.samples && output) {
+      pending.push(e.data.samples);
+      pendingLength += e.data.samples.length;
+    }
+  };
+
+  this.setBufferLength = function (length) {
+    output = new Int16Array(length);
+    //worker.postMessage({bufferLength:length,numChannels:2});
+    pendingLength = 0;
+  };
+
+  this.getBuffer = function () {
+    return output;
+  };
+
+  this.setSampleRate = function (rate) {
+    sampleRate = rate;
+    worker.postMessage({sampleRate:rate});
+  };
+
+  this.generate = function (length) {
+    if (pendingLength < length*3) {
+      //console.log(length, pendingLength);
+      output.fill(0);
+      return; // TODO: send sync msg?
+    }
+    for (var i=0; i<output.length;) {
+      if (pending.length == 0) break; // TODO?
+      var buf = pending.shift();
+      pendingLength -= buf.length;
+      var l = output.length-i;
+      if (buf.length < l) {
+        output.set(buf, i);
+      } else {
+        output.set(buf.slice(0, l), i);
+        pending.unshift(buf.slice(l));
+        pendingLength += buf.length-l;
+      }
+      i += buf.length;
+    }
+  }
+
+}

src/audio/testz80worker.html

@@ -0,0 +1,4 @@
+<script>
+var worker = new Worker("./z80worker.js");
+worker.postMessage({});
+</script>

src/audio/z80worker.js

@@ -0,0 +1,163 @@
+"use strict";
+
+/****************************************************************************
+
+    Midway/Williams Audio Boards
+    ----------------------------
+
+    6809 MEMORY MAP
+
+    Function                                  Address     R/W  Data
+    ---------------------------------------------------------------
+    Program RAM                               0000-07FF   R/W  D0-D7
+
+    Music (YM-2151)                           2000-2001   R/W  D0-D7
+
+    6821 PIA                                  4000-4003   R/W  D0-D7
+
+    HC55516 clock low, digit latch            6000        W    D0
+    HC55516 clock high                        6800        W    xx
+
+    Bank select                               7800        W    D0-D2
+
+    Banked Program ROM                        8000-FFFF   R    D0-D7
+
+****************************************************************************/
+
+var window = {};
+
+importScripts("../emu.js");
+importScripts("../cpu/z80.js");
+
+window.buildZ80({
+  applyContention: false
+});
+
+var cpu, ram, rom, membus, iobus;
+var audio;
+var command = 0;
+var dac = 0;
+var current_buffer;
+var last_tstate;
+
+var timer;
+var curTime;
+var timerPeriod = 20;
+var sampleRate;
+var numChannels = 2;
+var bufferLength;
+
+var cpuFrequency = 18432000/6; // 3.072 MHz
+var cpuCyclesPerFrame = cpuFrequency/60;
+var cpuAudioFactor = 32;
+
+
+function fillBuffer() {
+  var t = cpu.getTstates() / cpuAudioFactor;
+  while (last_tstate < t) {
+    current_buffer[last_tstate*2] = dac;
+    current_buffer[last_tstate*2+1] = dac;
+    last_tstate++;
+  }
+}
+
+function start() {
+  ram = new RAM(0x400);
+  rom = [0xe,0x0,0x6,0x0,0x78,0xb9,0x30,0x06,0xa9,0xd3,0x00,0x04,0x18,0xf6,0x0c,0x79,0xd6,0xff,0x38,0xee,0x76,0x18,0xea]; // TODO
+  membus = {
+    read: new AddressDecoder([
+      [0x0000, 0x3fff, 0x3fff, function(a) { return rom ? rom[a] : null; }],
+      [0x4000, 0x5fff, 0xfff,  function(a) { return ram.mem[a]; }]
+    ]),
+    write: new AddressDecoder([
+      [0x4000, 0x5fff, 0xfff,  function(a,v) { ram.mem[a] = v; }],
+    ]),
+    isContended: function() { return false; },
+  };
+  iobus = {
+    read: function(addr) {
+      return command & 0xff;
+    },
+    write: function(addr, val) {
+      dac = (val & 0xff) << 8;
+      fillBuffer();
+    }
+  };
+  cpu = window.Z80({
+    display: {},
+    memory: membus,
+    ioBus: iobus
+  });
+  current_buffer = new Int16Array(bufferLength);
+}
+
+function timerCallback() {
+  cpu.setTstates(0);
+  last_tstate = 0;
+  var numStates = Math.floor(bufferLength * cpuAudioFactor / numChannels);
+  cpu.runFrame(numStates);
+  //console.log(numStates, cpu.getTstates());
+  cpu.setTstates(numStates); // TODO?
+  fillBuffer();
+  postMessage({samples:current_buffer});
+  if (!cpu.getHalted()) {
+    curTime += timerPeriod;
+    var dt = curTime - new Date().getTime();
+    if (dt < 0) dt = 0;
+    timer = setTimeout(timerCallback, dt);
+  } else {
+    timer = 0;
+  }
+}
+
+function reset() {
+  if (!bufferLength) return;
+  cpu.reset();
+  if (!timer) {
+    curTime = new Date().getTime() - timerPeriod*4;
+    timerCallback();
+  }
+}
+
+onmessage = function(e) {
+  if (e && e.data) {
+    if (e.data.command) {
+      command = e.data.command & 0xff;
+      reset();
+    } else if (e.data.sampleRate) {
+      console.log(e.data);
+      sampleRate = e.data.sampleRate;
+      bufferLength = numChannels*sampleRate*timerPeriod/1000;
+      start();
+      reset();
+    }
+  }
+}
+
+
+/**
+
+0000                      56 _main::
+                          57 ;<stdin>:10:
+0000 0E 00         [ 7]   58 	ld	c,#0x00
+                          59 ;<stdin>:11:
+0002                      60 00111$:
+0002 06 00         [ 7]   61 	ld	b,#0x00
+0004                      62 00104$:
+0004 78            [ 4]   63 	ld	a,b
+0005 B9            [ 4]   64 	cp	a,c
+0006 30 06         [12]   65 	jr	NC,00107$
+0008 A9            [ 4]   66 	xor	a, c
+0009 D3 00         [11]   67 	out	(_dac),a
+000B 04            [ 4]   68 	inc	b
+000C 18 F6         [12]   69 	jr	00104$
+000E                      70 00107$:
+                          71 ;<stdin>:10:
+000E 0C            [ 4]   72 	inc	c
+000F 79            [ 4]   73 	ld	a,c
+0010 D6 FF         [ 7]   74 	sub	a, #0xff
+0012 38 EE         [12]   75 	jr	C,00111$
+                          76 ;<stdin>:13:
+0014 18 EA         [12]   77 	jr	_main
+
+**/

src/emu.js

@@ -248,15 +248,19 @@ var SampleAudio = function(clockfreq) {
     var m = this.module;
     if (!m) m = ape.srcElement.module;
     if (!m) return;
-
+    if (m.callback) {
+      m.callback(lbuf);
+      return;
+    } else {
       var buf = bufferlist[1];
       for (var i=0; i<lbuf.length; i++) {
         lbuf[i] = buf[i];
       }
     }
+  }
 
   function createContext() {
-    var AudioContext = AudioContext || webkitAudioContext || mozAudioContext;
+    var AudioContext = window.AudioContext || window.webkitAudioContext || window.mozAudioContext;
     if (! AudioContext) {
       console.log("no web audio context");
       return;
@@ -355,257 +359,6 @@ function cpuStateToLongString_6502(c) {
        + " Y " + hex(c.Y)    + "     " + "SP " + hex(c.SP) + "\n";
 }
 
-var MasterAudio = function() {
-  this.master = new MasterChannel();
-  this.start = function() {
-    this.looper = new AudioLooper(256);
-    this.looper.setChannel(this.master);
-    this.looper.activate();
-  }
-  this.stop = function() {
-    this.looper.setChannel(null);
-  }
-}
-
-var AY38910_Audio = function(master) {
-  this.psg = new PsgDeviceChannel();
-  this.psg.setMode(PsgDeviceChannel.MODE_SIGNED);
-  this.psg.setDevice(PsgDeviceChannel.DEVICE_AY_3_8910);
-  master.master.addChannel(this.psg);
-  var curreg = 0;
-
-  this.reset = function() {
-    for (var i=15; i>=0; i--) {
-      this.selectRegister(i);
-      this.setData(0);
-    }
-  }
-  this.selectRegister = function(val) {
-    curreg = val & 0xf;
-  }
-  this.setData = function(val) {
-    this.psg.writeRegisterAY(curreg, val & 0xff);
-  }
-}
-
-// https://en.wikipedia.org/wiki/POKEY
-// https://user.xmission.com/~trevin/atari/pokey_regs.html
-// http://krap.pl/mirrorz/atari/homepage.ntlworld.com/kryten_droid/Atari/800XL/atari_hw/pokey.htm
-
-var POKEYDeviceChannel = function() {
-
-  /* definitions for AUDCx (D201, D203, D205, D207) */
-  var NOTPOLY5    = 0x80     /* selects POLY5 or direct CLOCK */
-  var POLY4       = 0x40     /* selects POLY4 or POLY17 */
-  var PURE        = 0x20     /* selects POLY4/17 or PURE tone */
-  var VOL_ONLY    = 0x10     /* selects VOLUME OUTPUT ONLY */
-  var VOLUME_MASK = 0x0f     /* volume mask */
-
-  /* definitions for AUDCTL (D208) */
-  var POLY9       = 0x80     /* selects POLY9 or POLY17 */
-  var CH1_179     = 0x40     /* selects 1.78979 MHz for Ch 1 */
-  var CH3_179     = 0x20     /* selects 1.78979 MHz for Ch 3 */
-  var CH1_CH2     = 0x10     /* clocks channel 1 w/channel 2 */
-  var CH3_CH4     = 0x08     /* clocks channel 3 w/channel 4 */
-  var CH1_FILTER  = 0x04     /* selects channel 1 high pass filter */
-  var CH2_FILTER  = 0x02     /* selects channel 2 high pass filter */
-  var CLOCK_15    = 0x01     /* selects 15.6999kHz or 63.9210kHz */
-
-  /* for accuracy, the 64kHz and 15kHz clocks are exact divisions of
-     the 1.79MHz clock */
-  var DIV_64      = 28       /* divisor for 1.79MHz clock to 64 kHz */
-  var DIV_15      = 114      /* divisor for 1.79MHz clock to 15 kHz */
-
-  /* the size (in entries) of the 4 polynomial tables */
-  var POLY4_SIZE  = 0x000f
-  var POLY5_SIZE  = 0x001f
-  var POLY9_SIZE  = 0x01ff
-
-  var POLY17_SIZE = 0x0001ffff    /* else use the full 17 bits */
-
-  /* channel/chip definitions */
-  var CHAN1       = 0
-  var CHAN2       = 1
-  var CHAN3       = 2
-  var CHAN4       = 3
-  var CHIP1       = 0
-  var CHIP2       = 4
-  var CHIP3       = 8
-  var CHIP4       = 12
-  var SAMPLE      = 127
-
-  var FREQ_17_EXACT     = 1789790.0  /* exact 1.79 MHz clock freq */
-  var FREQ_17_APPROX    = 1787520.0  /* approximate 1.79 MHz clock freq */
-
-  // LFSR sequences
-  var bit1 = [ 0,1 ];
-  var bit4 = [ 1,1,0,1,1,1,0,0,0,0,1,0,1,0,0 ];
-  var bit5 = [ 0,0,1,1,0,0,0,1,1,1,1,0,0,1,0,1,0,1,1,0,1,1,1,0,1,0,0,0,0,0,1 ];
-  var bit17 = new Uint8Array(1<<17);
-  var bit17_5 = new Uint8Array(1<<17);
-  var bit5_4 = new Uint8Array(1<<17);
-  for (var i=0; i<bit17.length; i++) {
-    bit17[i] = Math.random() > 0.5;
-    bit17_5[i] = bit17[i] & bit5[i % bit5.length];
-    bit5_4[i] = bit5[i % bit5.length] & bit4[i % bit4.length];
-  }
-  var wavetones = [
-    bit17_5, bit5, bit5_4, bit5,
-    bit17, bit1, bit4, bit1
-  ];
-
-  // registers
-  var regs = new Uint8Array(16);
-  var counters = new Float32Array(4);
-  var deltas = new Float32Array(4);
-  var volume = new Float32Array(4);
-  var audc = new Uint8Array(4);
-  var waveforms = [bit1, bit1, bit1, bit1];
-  var buffer;
-  var sampleRate = 44100;
-  var clock, baseDelta;
-  var dirty = true;
-
-  //
-
-  this.setBufferLength = function (length) {
-    buffer = new Int32Array(length);
-  };
-
-  this.getBuffer = function () {
-    return buffer;
-  };
-
-  this.setSampleRate = function (rate) {
-    sampleRate = rate;
-    baseDelta = FREQ_17_EXACT / rate / 1.2; // TODO?
-  };
-
-  function updateValues(addr) {
-    var ctrl = regs[8];
-    var base = (ctrl & CLOCK_15) ? DIV_15 : DIV_64;
-    var div;
-    var i = addr & 4;
-    var j = i>>1;
-    var k = i>>2;
-    if (ctrl & (CH1_CH2>>k)) {
-      if (ctrl & (CH1_179>>k))
-         div = regs[i+2] * 256 + regs[i+0] + 7;
-      else
-         div = (regs[i+2] * 256 + regs[i+0] + 1) * base;
-      deltas[j+1] = baseDelta / div;
-      deltas[j+0] = 0;
-    } else {
-      if (ctrl & (CH1_179>>k)) {
-        div = regs[i+0] + 4;
-      } else {
-        div = (regs[i+0] + 1) * base;
-      }
-      deltas[j+0] = baseDelta / div;
-      div = (regs[i+2] + 1) * base;
-      deltas[j+1] = baseDelta / div;
-    }
-    //console.log(addr, ctrl.toString(16), div, deltas[j+0], deltas[j+1]);
-  }
-
-  this.setRegister = function(addr, value) {
-    addr &= 0xf;
-    value &= 0xff;
-    if (regs[addr] != value) {
-      regs[addr] = value;
-      switch (addr) {
-        case 0:
-        case 2:
-        case 4:
-        case 6: // AUDF
-        case 8: // ctrl
-          dirty = true;
-          break;
-        case 1:
-        case 3:
-        case 5:
-        case 7: // AUDC
-          volume[addr>>1] = value & 0xf;
-          waveforms[addr>>1] = wavetones[value>>5];
-          break;
-      }
-    }
-  }
-
-  this.generate = function (length) {
-    if (dirty) {
-      updateValues(0);
-      updateValues(4);
-      dirty = false;
-    }
-    for (var s=0; s<length; s+=2) {
-      var sample = 0;
-      for (var i=0; i<4; i++) {
-        var d = deltas[i];
-        var v = volume[i];
-        if (d > 0 && d < 1 && v > 0) {
-          var wav = waveforms[i];
-          var cnt = counters[i] += d;
-          if (cnt > POLY17_SIZE+1) {
-            counters[i] -= POLY17_SIZE+1;
-          }
-          var on = wav[Math.floor(cnt % wav.length)];
-          if (on) {
-            sample += v;
-          }
-        }
-      }
-      sample *= 273;
-      buffer[s] = sample;
-      buffer[s+1] = sample;
-    }
-  }
-}
-
-////// CPU sound
-
-var CPUSoundChannel = function(cpu, clockRate) {
-  var sampleRate;
-  var buffer;
-  var lastbufpos=0;
-  var curSample=0;
-  var clocksPerSample;
-
-  this.setBufferLength = function (length) {
-    buffer = new Int32Array(length);
-  };
-
-  this.getBuffer = function () {
-    return buffer;
-  };
-
-  this.setSampleRate = function (rate) {
-    sampleRate = rate;
-  };
-
-  this.getSetDACFunction = function() {
-    return function(a,v) {
-      var bufpos = Math.floor(cpu.getTstates() / clocksPerSample);
-      while (lastbufpos < bufpos)
-        buffer[lastbufpos++] = curSample;
-      lastbufpos = bufpos;
-      curSample = v;
-    };
-  };
-
-  this.generate = function (length) {
-    clocksPerSample = clockRate * 1.0 / sampleRate;
-    var clocks = Math.round(length * clocksPerSample);
-    if (cpu.getTstates && cpu.runFrame) {
-      cpu.setTstates(0);
-      lastbufpos = 0;
-      cpu.runFrame(cpu.getTstates() + totalClocks);
-      while (lastbufpos < length)
-        buffer[lastbufpos++] = curSample;
-    }
-  };
-}
-
 ////// 6502
 
 var Base6502Platform = function() {

src/platform/sound_williams.js

@@ -0,0 +1,159 @@
+"use strict";
+
+var WILLIAMS_SOUND_PRESETS = [
+  {id:'minimal.c', name:'Minimal Test'},
+];
+
+/****************************************************************************
+
+    Midway/Williams Audio Boards
+    ----------------------------
+
+    6809 MEMORY MAP
+
+    Function                                  Address     R/W  Data
+    ---------------------------------------------------------------
+    Program RAM                               0000-07FF   R/W  D0-D7
+
+    Music (YM-2151)                           2000-2001   R/W  D0-D7
+
+    6821 PIA                                  4000-4003   R/W  D0-D7
+
+    HC55516 clock low, digit latch            6000        W    D0
+    HC55516 clock high                        6800        W    xx
+
+    Bank select                               7800        W    D0-D2
+
+    Banked Program ROM                        8000-FFFF   R    D0-D7
+
+****************************************************************************/
+
+var WilliamsSoundPlatform = function(mainElement) {
+  var self = this;
+  this.__proto__ = new BaseZ80Platform();
+
+  var cpu, ram, rom, membus, iobus;
+  var audio, master;
+  var video, timer;
+  var command = 0;
+  var dac = 0;
+  var dac_float = 0.0
+  var current_buffer;
+  var last_tstate;
+  var pixels;
+
+  var cpuFrequency = 18432000/6; // 3.072 MHz
+  var cpuCyclesPerFrame = cpuFrequency/60;
+  var cpuAudioFactor = 32;
+
+  function fillBuffer() {
+    var t = cpu.getTstates() / cpuAudioFactor;
+    while (last_tstate < t) {
+      current_buffer[last_tstate++] = dac_float;
+    }
+  }
+
+  this.getPresets = function() {
+    return WILLIAMS_SOUND_PRESETS;
+  }
+
+  this.start = function() {
+    ram = new RAM(0x400);
+    membus = {
+      read: new AddressDecoder([
+				[0x0000, 0x3fff, 0x3fff, function(a) { return rom ? rom[a] : null; }],
+				[0x4000, 0x5fff, 0xfff,  function(a) { return ram.mem[a]; }]
+			]),
+			write: new AddressDecoder([
+				[0x4000, 0x5fff, 0xfff,  function(a,v) { ram.mem[a] = v; }],
+			]),
+      isContended: function() { return false; },
+    };
+    iobus = {
+      read: function(addr) {
+        return command & 0xff;
+    	},
+    	write: function(addr, val) {
+        dac = val & 0xff;
+        dac_float = ((dac & 0x80) ? -256+dac : dac) / 128.0;
+        fillBuffer();
+    	}
+    };
+    cpu = window.Z80({
+  		display: {},
+  		memory: membus,
+  		ioBus: iobus
+  	});
+    audio = new SampleAudio(cpuFrequency / cpuAudioFactor);
+    audio.callback = function(lbuf) {
+      if (self.isRunning()) {
+        cpu.setTstates(0);
+        current_buffer = lbuf;
+        last_tstate = 0;
+        self.runCPU(cpu, lbuf.length * cpuAudioFactor);
+        cpu.setTstates(lbuf.length * cpuAudioFactor); // TODO?
+        fillBuffer();
+        for (var i=0; i<256; i++) {
+          var y = Math.round((current_buffer[i] * 127) + 128);
+          pixels[i + y*256] = 0xff33ff33;
+        }
+      }
+    };
+    video = new RasterVideo(mainElement,256,256);
+    video.create();
+    video.setKeyboardEvents(function(key,code,flags) {
+      var intr = (key-49);
+      if (intr >= 0 && (flags & 1)) {
+        command = intr & 0xff;
+        cpu.reset();
+      }
+    });
+    pixels = video.getFrameData();
+    timer = new AnimationTimer(30, function() {
+      if (self.isRunning()) {
+        video.updateFrame();
+        pixels.fill(0);
+      }
+    });
+  }
+
+  this.loadROM = function(title, data) {
+    rom = padBytes(data, 0x4000);
+    cpu.reset();
+  }
+
+  this.loadState = function(state) {
+    cpu.loadState(state.c);
+    ram.mem.set(state.b);
+  }
+  this.saveState = function() {
+    return {
+      c:self.getCPUState(),
+      b:ram.mem.slice(0),
+    };
+  }
+  this.getCPUState = function() {
+    return cpu.saveState();
+  }
+
+  this.isRunning = function() {
+    return timer.isRunning();
+  }
+  this.pause = function() {
+    timer.stop();
+    audio.stop();
+  }
+  this.resume = function() {
+    timer.start();
+    audio.start();
+  }
+  this.reset = function() {
+    cpu.reset();
+    if (!this.getDebugCallback()) cpu.setTstates(0); // TODO?
+  }
+  this.readAddress = function(addr) {
+    return membus.read(addr); // TODO?
+  }
+}
+
+PLATFORMS['sound_williams-z80'] = WilliamsSoundPlatform;

src/platform/williams.js

@@ -25,6 +25,8 @@ var WilliamsPlatform = function(mainElement, proto) {
   var membus, iobus;
   var video_counter;
 
+  var audio, worker, workerchannel;
+
   var xtal = 12000000;
   var cpuFrequency = xtal/3/4;
   var cpuCyclesPerFrame = cpuFrequency/60; // TODO
@@ -126,8 +128,9 @@ var WilliamsPlatform = function(mainElement, proto) {
 
   var iowrite_williams = new AddressDecoder([
     [0x0,   0xf,   0xf,   setPalette],
-    [0x804, 0x807, 0x3,   function(a,v) { console.log('iowrite',a); }], // TODO: sound
+    [0x803, 0x803, 0xf,   function(a,v) { if (worker) worker.postMessage({command:v}); }],
-    [0x80c, 0x80f, 0x3,   function(a,v) { console.log('iowrite',a+4); }], // TODO: sound
+    //[0x804, 0x807, 0x3,   function(a,v) { console.log('iowrite',a); }], // TODO: sound
+    //[0x80c, 0x80f, 0x3,   function(a,v) { console.log('iowrite',a+4); }], // TODO: sound
     [0x900, 0x9ff, 0,     function(a,v) { banksel = v & 0x1; }],
     [0xa00, 0xa07, 0x7,   setBlitter],
     [0xbff, 0xbff, 0,     function(a,v) { if (v == 0x39) watchdog_counter = INITIAL_WATCHDOG; }],
@@ -275,6 +278,12 @@ var WilliamsPlatform = function(mainElement, proto) {
 			write: memwrite_williams,
     };
     cpu = self.newCPU(membus);
+
+    audio = new MasterAudio();
+    worker = new Worker("./src/audio/z80worker.js");
+		workerchannel = new WorkerSoundChannel(worker);
+    audio.master.addChannel(workerchannel);
+
     video = new RasterVideo(mainElement, SCREEN_WIDTH, SCREEN_HEIGHT, {rotate:-90});
     video.create();
 		$(video.canvas).click(function(e) {
@@ -354,9 +363,11 @@ var WilliamsPlatform = function(mainElement, proto) {
   }
   this.pause = function() {
     timer.stop();
+    audio.stop();
   }
   this.resume = function() {
     timer.start();
+    audio.start();
   }
   this.reset = function() {
     cpu.reset();

src/worker/workermain.js

@@ -37,6 +37,12 @@ var PLATFORM_PARAMS = {
     data_start: 0xe000,
     data_size: 0x2000,
   },
+  'sound_williams-z80': {
+    code_start: 0x0,
+    code_size: 0x4000,
+    data_start: 0x4000,
+    data_size: 0x1000,
+  },
 };
 
 var loaded = {}