diff --git a/index.html b/index.html
index e33b65ba..182b6245 100644
--- a/index.html
+++ b/index.html
@@ -99,6 +99,10 @@ div.mem_info {
   font-family: "Andale Mono", "Menlo", "Lucida Console", monospace;
   font-size: 12pt;
 }
+.seg_code { color: #ff9966; }
+.seg_data { color: #66ff66; }
+.seg_stack { color: #ffff66; }
+.seg_unknown { color: #cccccc; }
 span.hilite {
   color: #ff66ff;
 }
diff --git a/src/emu.js b/src/emu.js
index 0522cbfc..4d02f2f6 100644
--- a/src/emu.js
+++ b/src/emu.js
@@ -441,21 +441,32 @@ function cpuStateToLongString_Z80(c) {
 
 var BaseZ80Platform = function() {
 
+  var _cpu;
+  var probe;
+
   window.buildZ80({
   	applyContention: false // TODO???
   });
 
-  // TODO: refactor w/ platforms
   this.newCPU = function(membus, iobus) {
-    return window.Z80({
+    probe = new BusProbe(membus);
+    _cpu = window.Z80({
      display: {},
-     memory: membus,
+     memory: probe,
      ioBus: iobus
    });
+   return _cpu;
   }
 
+  this.getProbe = function() { return probe; }
+  this.getPC = function() { return _cpu.getPC(); }
+  this.getSP = function() { return _cpu.getSP(); }
+
   // TODO: refactor other parts into here
   this.runCPU = function(cpu, cycles) {
+    _cpu = cpu; // TODO?
+    if (this.wasBreakpointHit())
+      return 0;
     var debugCond = this.getDebugCallback();
     var targetTstates = cpu.getTstates() + cycles;
     if (debugCond) { // || trace) {
diff --git a/src/platform/galaxian.js b/src/platform/galaxian.js
index cf98249b..9c826d93 100644
--- a/src/platform/galaxian.js
+++ b/src/platform/galaxian.js
@@ -264,8 +264,8 @@ var GalaxianPlatform = function(mainElement, options) {
         isContended: function() { return false; },
       };
     }
-    this.readMemory = function(a) {
-      return (a == 0x7000 || a == 0x7800) ? null : membus.read; // ignore watchdog
+    this.readAddress = function(a) {
+      return (a == 0x7000 || a == 0x7800) ? null : membus.read(a); // ignore watchdog
     };
     audio = new MasterAudio();
     psg1 = new AY38910_Audio(audio);
@@ -387,9 +387,6 @@ var GalaxianPlatform = function(mainElement, options) {
     if (!this.getDebugCallback()) cpu.setTstates(0); // TODO?
     watchdog_counter = INITIAL_WATCHDOG;
   }
-  this.readAddress = function(addr) {
-    return membus.read(addr); // TODO?
-  }
 }
 
 var GalaxianScramblePlatform = function(mainElement) {
diff --git a/src/platform/mw8080bw.js b/src/platform/mw8080bw.js
index 3d6d1844..aa24eed7 100644
--- a/src/platform/mw8080bw.js
+++ b/src/platform/mw8080bw.js
@@ -13,6 +13,7 @@ var Midway8080BWPlatform = function(mainElement) {
   this.__proto__ = new BaseZ80Platform();
 
   var cpu, ram, membus, iobus, rom;
+  var probe;
   var video, timer, pixels, displayPCs;
   var inputs = [0xe,0x8,0x0];
   var bitshift_offset = 0;
@@ -60,7 +61,7 @@ var Midway8080BWPlatform = function(mainElement) {
 			]),
       isContended: function() { return false; },
     };
-    this.readMemory = membus.read;
+    this.readAddress = membus.read;
     iobus = {
       read: function(addr) {
 				addr &= 0x3;
@@ -96,11 +97,7 @@ var Midway8080BWPlatform = function(mainElement) {
         }
     	}
     };
-    cpu = window.Z80({
-  		display: {},
-  		memory: membus,
-  		ioBus: iobus
-  	});
+    cpu = this.newCPU(membus, iobus);
     video = new RasterVideo(mainElement,256,224,{rotate:-90});
     video.create();
 		$(video.canvas).click(function(e) {
@@ -191,9 +188,6 @@ var Midway8080BWPlatform = function(mainElement) {
     cpu.setTstates(0);
     watchdog_counter = INITIAL_WATCHDOG;
   }
-  this.readAddress = function(addr) {
-    return membus.read(addr);
-  }
 }
 
 PLATFORMS['mw8080bw'] = Midway8080BWPlatform;
diff --git a/src/platform/sound_konami.js b/src/platform/sound_konami.js
index c88d109d..00d063f5 100644
--- a/src/platform/sound_konami.js
+++ b/src/platform/sound_konami.js
@@ -56,11 +56,8 @@ var KonamiSoundPlatform = function(mainElement) {
         }
     	}
     };
-    cpu = window.Z80({
-  		display: {},
-  		memory: membus,
-  		ioBus: iobus
-  	});
+    this.readAddress = membus.read;
+    cpu = this.newCPU(membus, iobus);
     psg = new PsgDeviceChannel();
     master = new MasterChannel();
     psg.setMode(PsgDeviceChannel.MODE_SIGNED);
@@ -136,9 +133,6 @@ var KonamiSoundPlatform = function(mainElement) {
     cpu.reset();
     if (!this.getDebugCallback()) cpu.setTstates(0); // TODO?
   }
-  this.readAddress = function(addr) {
-    return membus.read(addr); // TODO?
-  }
 }
 
 PLATFORMS['sound_konami'] = KonamiSoundPlatform;
diff --git a/src/platform/sound_williams.js b/src/platform/sound_williams.js
index 2f8d6fa6..60a9ae02 100644
--- a/src/platform/sound_williams.js
+++ b/src/platform/sound_williams.js
@@ -79,11 +79,8 @@ var WilliamsSoundPlatform = function(mainElement) {
         fillBuffer();
     	}
     };
-    cpu = window.Z80({
-  		display: {},
-  		memory: membus,
-  		ioBus: iobus
-  	});
+    this.readAddress = membus.read;
+    cpu = this.newCPU(membus, iobus);
     audio = new SampleAudio(cpuFrequency / cpuAudioFactor);
     audio.callback = function(lbuf) {
       if (self.isRunning()) {
@@ -151,9 +148,6 @@ var WilliamsSoundPlatform = function(mainElement) {
     cpu.reset();
     if (!this.getDebugCallback()) cpu.setTstates(0); // TODO?
   }
-  this.readAddress = function(addr) {
-    return membus.read(addr); // TODO?
-  }
 }
 
 PLATFORMS['sound_williams-z80'] = WilliamsSoundPlatform;
diff --git a/src/platform/vector.js b/src/platform/vector.js
index c134a557..577e92b6 100644
--- a/src/platform/vector.js
+++ b/src/platform/vector.js
@@ -90,7 +90,7 @@ var AtariVectorPlatform = function(mainElement) {
       ], {gmask:0x7fff})
 
     };
-    this.readMemory = membus.read;
+    this.readAddress = bus.read;
     cpu = self.newCPU(bus);
     // create video/audio
     video = new VectorVideo(mainElement,1024,1024);
@@ -147,9 +147,6 @@ var AtariVectorPlatform = function(mainElement) {
     this.clearDebug();
     cpu.reset();
   }
-  this.readAddress = function(addr) {
-    return bus.read(addr);
-  }
 
   this.loadState = function(state) {
     cpu.loadState(state.c);
@@ -240,6 +237,7 @@ var AtariColorVectorPlatform = function(mainElement) {
       ])
 
     };
+    this.readAddress = bus.read;
     cpu = self.newCPU(bus);
     // create video/audio
     video = new VectorVideo(mainElement,1024,1024);
@@ -291,9 +289,6 @@ var AtariColorVectorPlatform = function(mainElement) {
     this.clearDebug();
     cpu.reset();
   }
-  this.readAddress = function(addr) {
-    return bus.read(addr);
-  }
 
   this.loadState = function(state) {
     cpu.loadState(state.c);
@@ -376,6 +371,7 @@ var Z80ColorVectorPlatform = function(mainElement, proto) {
       ])
 
     };
+    this.readAddress = bus.read;
     cpu = self.newCPU(bus);
     // create video/audio
     video = new VectorVideo(mainElement,1024,1024);
@@ -420,9 +416,6 @@ var Z80ColorVectorPlatform = function(mainElement, proto) {
     switches[0xe] = 16;
     cpu.reset();
   }
-  this.readAddress = function(addr) {
-    return bus.read(addr);
-  }
 
   this.loadState = function(state) {
     cpu.loadState(state.c);
diff --git a/src/platform/vicdual.js b/src/platform/vicdual.js
index f360ffae..ebb9c9fe 100644
--- a/src/platform/vicdual.js
+++ b/src/platform/vicdual.js
@@ -15,7 +15,7 @@ var VicDualPlatform = function(mainElement) {
   this.__proto__ = new BaseZ80Platform();
 
   var cpu, ram, membus, iobus, rom;
-  var video, audio, psg, timer, pixels, probe;
+  var video, audio, psg, timer, pixels;
   var inputs = [0xff, 0xff, 0xff, 0xff^0x8]; // most things active low
 	var palbank = 0;
 
@@ -108,7 +108,7 @@ var VicDualPlatform = function(mainElement) {
 			]),
       isContended: function() { return false; },
     };
-    this.readMemory = membus.read;
+    this.readAddress = membus.read;
     iobus = {
       read: function(addr) {
         return inputs[addr&3];
@@ -120,12 +120,7 @@ var VicDualPlatform = function(mainElement) {
 				if (addr & 0x40) { palbank = val & 3; }; // palette
     	}
     };
-    probe = new BusProbe(membus);
-    cpu = window.Z80({
-  		display: {},
-  		memory: probe,
-  		ioBus: iobus
-  	});
+    cpu = this.newCPU(membus, iobus);
     video = new RasterVideo(mainElement,256,224,{rotate:-90});
     audio = new MasterAudio();
 		psg = new AY38910_Audio(audio);
@@ -154,14 +149,7 @@ var VicDualPlatform = function(mainElement) {
         targetTstates += cpuCyclesPerLine;
 				if (sl == vblankStart) inputs[1] |= 0x8;
 				if (sl == vsyncEnd) inputs[1] &= ~0x8;
-        if (debugCond) {
-          while (cpu.getTstates() < targetTstates) {
-            if (debugCond && debugCond()) { debugCond = null; }
-            cpu.runFrame(cpu.getTstates() + 1);
-          }
-        } else {
-          cpu.runFrame(targetTstates);
-        }
+        self.runCPU(cpu, targetTstates - cpu.getTstates());
       }
       video.updateFrame();
       self.restartDebugState();
@@ -216,16 +204,12 @@ var VicDualPlatform = function(mainElement) {
 		psg.reset();
     if (!this.getDebugCallback()) cpu.setTstates(0); // TODO?
   }
-  this.readAddress = function(addr) {
-    return membus.read(addr & 0xffff); // TODO?
-  }
   this.setFrameStats = function(on) {
     framestats = on ? {
       palette: palette,
       layers: {width:256, height:224, tiles:[]}
     } : null;
   }
-  this.getProbe = function() { return probe; }
 }
 
 PLATFORMS['vicdual'] = VicDualPlatform;
diff --git a/src/platform/williams.js b/src/platform/williams.js
index dd4b4f8f..e4cc9f25 100644
--- a/src/platform/williams.js
+++ b/src/platform/williams.js
@@ -273,13 +273,12 @@ var WilliamsPlatform = function(mainElement, proto) {
     nvram = new RAM(0x400);
     // TODO: save in browser storage?
     //displayPCs = new Uint16Array(new ArrayBuffer(0x9800*2));
-    rom = padBytes(new lzgmini().decode(ROBOTRON_ROM).slice(0), 0xc001);
+    //rom = padBytes(new lzgmini().decode(ROBOTRON_ROM).slice(0), 0xc001);
     membus = {
       read: memread_williams,
 			write: memwrite_williams,
     };
-    this.readMemory = membus.read;
-    //var probebus = new BusProbe(membus);
+    this.readAddress = membus.read;
     var iobus = {
       read: function(a) {return 0;},
       write: function(a,v) {console.log(hex(a),hex(v));}
@@ -317,13 +316,11 @@ var WilliamsPlatform = function(mainElement, proto) {
               cpu.requestInterrupt();
           }
         }
-        if (!self.wasBreakpointHit())
-          self.runCPU(cpu, cpuCyclesPerSection);
+        self.runCPU(cpu, cpuCyclesPerSection);
         if (sl < 256) video.updateFrame(0, 0, 256-4-sl, 0, 4, 304);
       }
       // last 6 lines
-      if (!self.wasBreakpointHit())
-        self.runCPU(cpu, cpuCyclesPerSection*2);
+      self.runCPU(cpu, cpuCyclesPerSection*2);
       if (screenNeedsRefresh) {
         for (var i=0; i<0x9800; i++)
           drawDisplayByte(i, ram.mem[i]);
@@ -400,9 +397,6 @@ var WilliamsPlatform = function(mainElement, proto) {
     watchdog_counter = INITIAL_WATCHDOG;
     banksel = 1;
   }
-  this.readAddress = function(addr) {
-    return membus.read(addr);
-  }
   this.scaleCPUFrequency = function(scale) {
     cpuScale = scale;
     cpuFrequency *= scale;
diff --git a/src/ui.js b/src/ui.js
index a352aaed..4edc755f 100644
--- a/src/ui.js
+++ b/src/ui.js
@@ -110,11 +110,14 @@ var TOOL_TO_SOURCE_STYLE = {
 }
 
 var worker = new Worker("./src/worker/workermain.js");
-var current_output = null;
-var current_preset_index = -1; // TODO: use URL
-var current_preset_id = null;
-var assemblyfile = null;
-var sourcefile = null;
+var current_output;
+var current_preset_index = -1;
+var current_preset_id;
+var assemblyfile;
+var sourcefile;
+var symbolmap;
+var addr2symbol;
+var compparams;
 var trace_pending_at_pc;
 var store;
 var pendingWorkerMessages = 0;
@@ -367,11 +370,23 @@ function arrayCompare(a,b) {
   return true;
 }
 
+function invertMap(m) {
+  var r = {};
+  if (m) {
+    for (var k in m) r[m[k]] = k;
+  }
+  return r;
+}
+
 function setCompileOutput(data) {
   sourcefile = new SourceFile(data.lines);
   if (data.asmlines) {
     assemblyfile = new SourceFile(data.asmlines, data.intermediate.listing);
   }
+  symbolmap = data.symbolmap;
+  addr2symbol = invertMap(symbolmap);
+  addr2symbol[0x10000] = '__END__';
+  compparams = data.params;
   // errors?
   function addErrorMarker(line, msg) {
     var div = document.createElement("div");
@@ -406,8 +421,7 @@ function setCompileOutput(data) {
         platform.loadROM(getCurrentPresetTitle(), rom);
         resume();
         current_output = rom;
-        prof_reads = [];
-        prof_writes = [];
+        resetProfiler();
         toolbar.removeClass("has-errors");
       } catch (e) {
         console.log(e); // TODO: show error
@@ -711,6 +725,16 @@ function _breakExpression() {
   }
 }
 
+function getSymbolAtAddress(a) {
+  if (addr2symbol[a]) return addr2symbol[a];
+  var i=0;
+  while (--a >= 0) {
+    i++;
+    if (addr2symbol[a]) return addr2symbol[a] + '+' + i;
+  }
+  return '';
+}
+
 function updateDebugWindows() {
   if (platform.isRunning()) {
     updateMemoryWindow();
@@ -719,14 +743,6 @@ function updateDebugWindows() {
   setTimeout(updateDebugWindows, 200);
 }
 
-function getProfileLine(line) {
-  var offset = sourcefile.line2offset[line];
-  if (offset >= 0) {
-    if (prof_reads[offset] > 0)
-      return ""+prof_reads[offset];
-  }
-}
-
 function updateProfileWindow() {
   if (profileview && sourcefile) {
     $("#profileview").find('[data-index]').each(function(i,e) {
@@ -746,22 +762,41 @@ function updateMemoryWindow() {
   if (memoryview) {
     $("#memoryview").find('[data-index]').each(function(i,e) {
       var div = $(e);
-      var offset = div.attr('data-index') * 16;
+      var row = div.attr('data-index');
       var oldtext = div.text();
-      var newtext = getMemoryLineAtOffset(offset);
+      var newtext = getMemoryLineAt(row);
       if (oldtext != newtext)
         div.text(newtext);
     });
   }
 }
 
-function getMemoryLineAtOffset(offset) {
+function getMemoryLineAt(row) {
+  var offset = row * 16;
+  var n1 = 0;
+  var n2 = 16;
+  var sym;
+  if (getDumpLines()) {
+    var dl = dumplines[row];
+    if (dl) {
+      offset = dl.a & 0xfff0;
+      n1 = dl.a - offset;
+      n2 = n1 + dl.l;
+      sym = dl.s;
+    } else {
+      return '.';
+    }
+  }
   var s = hex(offset,4) + ' ';
-  for (var i=0; i<16; i++) {
-    var read = platform.readMemory(offset+i);
+  for (var i=0; i<n1; i++) s += '   ';
+  if (n1 > 8) s += ' ';
+  for (var i=n1; i<n2; i++) {
+    var read = platform.readAddress(offset+i);
     if (i==8) s += ' ';
     s += ' ' + (read>=0?hex(read,2):'??');
   }
+  for (var i=n2; i<16; i++) s += '   ';
+  if (sym) s += '  ' + sym;
   return s;
 }
 
@@ -769,6 +804,56 @@ function getEditorLineHeight() {
   return $("#editor").find(".CodeMirror-line").first().height();
 }
 
+function getDumpLineAt(line) {
+  var d = dumplines[line];
+  if (d) {
+    return d.a + " " + d.s;
+  }
+}
+
+var IGNORE_SYMS = {s__INITIALIZER:true, /* s__GSINIT:true, */ _color_prom:true};
+
+function getDumpLines() {
+  if (!dumplines && addr2symbol) {
+    dumplines = [];
+    var ofs = 0;
+    var sym;
+    for (var nextofs in addr2symbol) {
+      nextofs |= 0;
+      var nextsym = addr2symbol[nextofs];
+      if (sym) {
+        if (IGNORE_SYMS[sym]) {
+          ofs = nextofs;
+        } else {
+          while (ofs < nextofs) {
+            var ofs2 = (ofs + 16) & 0xffff0;
+            if (ofs2 > nextofs) ofs2 = nextofs;
+            //if (ofs < 1000) console.log(ofs, ofs2, nextofs, sym);
+            dumplines.push({a:ofs, l:ofs2-ofs, s:sym});
+            ofs = ofs2;
+          }
+        }
+      }
+      sym = nextsym;
+    }
+  }
+  return dumplines;
+}
+
+function getMemorySegment(a) {
+  if (!compparams) return 'unknown';
+  if (a >= compparams.data_start && a < compparams.data_start+compparams.data_size) {
+    if (platform.getSP && a >= platform.getSP() - 15)
+      return 'stack';
+    else
+      return 'data';
+  }
+  else if (a >= compparams.code_start && a < compparams.code_start+compparams.code_size)
+    return 'code';
+  else
+    return 'unknown';
+}
+
 function showMemoryWindow() {
   memoryview = new VirtualList({
     w:$("#emulator").width(),
@@ -776,15 +861,19 @@ function showMemoryWindow() {
     itemHeight: getEditorLineHeight(),
     totalRows: 0x1000,
     generatorFn: function(row) {
-      var s = getMemoryLineAtOffset(row * 16);
+      var s = getMemoryLineAt(row);
       var div = document.createElement("div");
+      if (dumplines) {
+        var dlr = dumplines[row];
+        if (dlr) div.classList.add('seg_' + getMemorySegment(dumplines[row].a));
+      }
       div.appendChild(document.createTextNode(s));
       return div;
     }
   });
   $("#memoryview").empty().append(memoryview.container);
   updateMemoryWindow();
-  memoryview.scrollToItem(0x800); // TODO
+  memoryview.scrollToItem(0); // TODO
 }
 
 function toggleMemoryWindow() {
@@ -816,13 +905,59 @@ function createProfileWindow() {
   updateProfileWindow();
 }
 
+var pcdata = {};
 var prof_reads, prof_writes;
+var dumplines;
+
+function resetProfiler() {
+  prof_reads = [];
+  prof_writes = [];
+  pcdata = [];
+  dumplines = null;
+}
 
 function profileWindowCallback(a,v) {
-  if (v >= 0) {
-    prof_writes[a] = (prof_writes[a]|0)+1;
+  if (platform.getPC) {
+    var pc = platform.getPC();
+    var pcd = pcdata[pc];
+    if (!pcd) {
+      pcd = pcdata[pc] = {nv:1};
+    }
+    pcd.nv++;
+    if (a != pc) {
+      if (v >= 0) {
+        pcd.lastwa = a;
+        pcd.lastwv = v;
+      } else {
+        pcd.lastra = a;
+        pcd.lastrv = platform.readAddress(a);
+      }
+    }
   } else {
-    prof_reads[a] = (prof_reads[a]|0)+1;
+    // TODO
+    if (v >= 0) {
+      prof_writes[a] = (prof_writes[a]|0)+1;
+    } else {
+      prof_reads[a] = (prof_reads[a]|0)+1;
+    }
+  }
+}
+
+function getProfileLine(line) {
+  var offset = sourcefile.line2offset[line];
+  if (offset >= 0) {
+    var pcd = pcdata[offset];
+    if (pcd) {
+      var s = pcd.nv+"";
+      while (s.length < 8) { s = ' '+s; }
+      if (pcd.lastra >= 0) {
+        s += " read [" + hex(pcd.lastra,4) + "] == " + hex(pcd.lastrv,2);
+      }
+      if (pcd.lastwa >= 0) {
+        s += " write " + hex(pcd.lastwv,2) + " -> [" + hex(pcd.lastwa,4) + "]";
+      }
+      return s;
+    }
   }
 }
 
@@ -965,8 +1100,8 @@ function startPlatform() {
     showWelcomeMessage();
     // start platform and load file
     preloadWorker(qs['file']);
-    setupDebugControls();
     platform.start();
+    setupDebugControls();
     loadPreset(qs['file']);
     updateSelector();
     return true;
diff --git a/src/worker/workermain.js b/src/worker/workermain.js
index 0253d3c9..842690a8 100644
--- a/src/worker/workermain.js
+++ b/src/worker/workermain.js
@@ -6,42 +6,49 @@ var PLATFORM_PARAMS = {
     code_size: 0x2000,
     data_start: 0x2000,
     data_size: 0x400,
+    stack_end: 0x2400,
   },
   'vicdual': {
     code_start: 0x0,
     code_size: 0x4020,
     data_start: 0xe400,
     data_size: 0x400,
+    stack_end: 0xe800,
   },
   'galaxian': {
     code_start: 0x0,
     code_size: 0x4000,
     data_start: 0x4000,
     data_size: 0x400,
+    stack_end: 0x4800,
   },
   'galaxian-scramble': {
     code_start: 0x0,
     code_size: 0x5020,
     data_start: 0x4000,
     data_size: 0x400,
+    stack_end: 0x4800,
   },
   'williams-z80': {
     code_start: 0x0,
     code_size: 0x9800,
     data_start: 0x9800,
     data_size: 0x2800,
+    stack_end: 0xc000,
   },
   'vector-z80color': {
     code_start: 0x0,
     code_size: 0x8000,
     data_start: 0xe000,
     data_size: 0x2000,
+    stack_end: 0x0,
   },
   'sound_williams-z80': {
     code_start: 0x0,
     code_size: 0x4000,
     data_start: 0x4000,
     data_size: 0x400,
+    stack_end: 0x8000,
   },
 };
 
@@ -685,22 +692,19 @@ function assemblelinkSDASZ80(code, platform) {
     var asmlines = parseListing(lstout, /^\s*([0-9A-F]+)\s+([0-9A-F][0-9A-F r]*[0-9A-F])\s+\[([0-9 ]+)\]\s+(\d+) (.*)/i, 4, 1, 2, 5, 3);
     var srclines = parseSourceLines(lstout, /^\s+\d+ ;<stdin>:(\d+):/i, /^\s*([0-9A-F]{4})/i);
     // parse symbol map
-    /*
     var symbolmap = {};
-    console.log(mapout);
     for (var s of mapout.split("\n")) {
       var toks = s.split(" ");
-      if (s[0] == 'DEF') {
-        symbolmap[s[1]] = s[2];
+      if (toks[0] == 'DEF' && !toks[1].startsWith("A$main$")) {
+        symbolmap[toks[1]] = parseInt(toks[2], 16);
       }
     }
-    */
     return {
       output:parseIHX(hexout, params.code_start, params.code_size),
       lines:asmlines,
       srclines:srclines,
       errors:msvc_errors, // TODO?
-      symbolmap:mapout,
+      symbolmap:symbolmap,
       intermediate:{listing:rstout},
     };
   }
@@ -897,6 +901,7 @@ onmessage = function(e) {
   var toolfn = TOOLS[e.data.tool];
   if (!toolfn) throw "no tool named " + e.data.tool;
   var result = toolfn(code, platform);
+  result.params = PLATFORM_PARAMS[platform];
   if (result) {
     postMessage(result);
   }