Extended write hooks and debugged sound

web/esop-ext.js

@@ -44,13 +44,13 @@ function ESOPExtensions() {
     //setup screen renderer
     function renderScreen() {
       var vram = vm.getram(vramOffset, vramSize),
-          vdata = ctx.getImageData(0,0,width,height),
+          vdata = ctx.createImageData(width,height),
           ppos, pval, vbval, i, j
-      for(i=0;i<vRamSize;i++) {
+      for(i=0;i<vramSize;i++) {
         vbval = vram[i]
         for(j=0;j<8;j++) { //iterate from highest to lowest
           ppos = ((i<<3) + j) << 2
-          pval = (vbval>>>(7-j))&1 ? 255 : 0
+          pval = (vbval>>>(7-j))&1 ? 0 : 0xee
           vdata.data[ppos] = pval
           vdata.data[ppos+1] = pval
           vdata.data[ppos+2] = pval
@@ -129,18 +129,24 @@ function ESOPExtensions() {
   function setupAudio(vm, actx) {
     var osc = null //keep the existing oscillator reference here
     vm.setdev(6,0)
-    vm.setWriteHook(6, function(port, portval) {
-      if(osc && !portval) { //stop the note
-        osc.stop()
-        osc.disconnect()
-        osc = null
-      }
-      else if(portval < sfl) { //start the note
-        osc = actx.createOscillator()
-        osc.type = 'square'
-        osc.frequency = soundFreqs[portval]
-        osc.connect(actx.destination)
-        osc.start(0)
+    vm.setWriteHook(6, function(port, portval, prev) {
+      if(portval !== prev) {
+        if(osc && !portval) { //stop the note
+          osc.stop()
+          osc.disconnect()
+          osc = null
+        }
+        if(portval && portval < sfl) { //start the note
+          if(osc)
+            osc.frequency.value = soundFreqs[portval]
+          else {
+            osc = actx.createOscillator()
+            osc.type = 'square'
+            osc.connect(actx.destination)
+            osc.frequency.value = soundFreqs[portval]
+            osc.start(0)
+          }
+        }
       }
     })
   }