diff --git a/src/baseplatform.ts b/src/baseplatform.ts
index 193a09e7..4a478340 100644
--- a/src/baseplatform.ts
+++ b/src/baseplatform.ts
@@ -50,7 +50,7 @@ export class DebugSymbols {
     this.symbolmap = symbolmap;
     this.addr2symbol = invertMap(symbolmap);
     //// TODO: shouldn't be necc.
-    if (!this.addr2symbol[0x0]) this.addr2symbol[0x0] = '__START__'; // needed for ...
+    if (!this.addr2symbol[0x0]) this.addr2symbol[0x0] = ' '; // needed for ...
     this.addr2symbol[0x10000] = '__END__'; // ... dump memory to work
   }
 }
@@ -1089,7 +1089,6 @@ export abstract class Base6502MachinePlatform<T extends Machine> extends BaseMac
       default: return isDebuggable(this.machine) && this.machine.getDebugInfo(category, state);
     }
   }
-
 }
 
 export abstract class BaseZ80MachinePlatform<T extends Machine> extends BaseMachinePlatform<T> {
diff --git a/src/devices.ts b/src/devices.ts
index 64fdb3f7..c8ac3b63 100644
--- a/src/devices.ts
+++ b/src/devices.ts
@@ -351,6 +351,7 @@ export abstract class BasicMachine implements HasCPU, Bus, SampledAudioSource, A
   connectCPUIOBus(iobus:Bus) : void {
     this.cpu['connectIOBus'](this.probeIOBus(iobus));
   }
+  // TODO: probe interrupts
 }
 
 export abstract class BasicScanlineMachine extends BasicMachine implements RasterFrameBased {
diff --git a/src/platform/nes.ts b/src/platform/nes.ts
index 59c6ccbc..b89ea33b 100644
--- a/src/platform/nes.ts
+++ b/src/platform/nes.ts
@@ -144,23 +144,6 @@ class JSNESPlatform extends Base6502Platform implements Platform, Probeable {
       this.probe.logClocks(cycles);
       return cycles;
     }
-    var ppu = this.nes.ppu;
-    var old_endScanline = ppu.endScanline.bind(ppu);
-    var old_startFrame = ppu.startFrame.bind(ppu);
-    var old_writeMem = ppu.writeMem.bind(ppu);
-    ppu.endScanline = () => {
-      old_endScanline();
-      this.probe.logNewScanline();
-    }
-    ppu.startFrame = () => {
-      old_startFrame();
-      this.probe.logNewFrame();
-    }
-    ppu.writeMem = (a,v) => {
-      old_writeMem(a,v);
-      this.probe.logVRAMWrite(a,v);
-    }
-    
     this.timer = new AnimationTimer(60, this.nextFrame.bind(this));
     // set keyboard map
     this.poller = setKeyboardFromMap(this.video, [], JSNES_KEYCODE_MAP, (o,key,code,flags) => {
@@ -221,33 +204,55 @@ class JSNESPlatform extends Base6502Platform implements Platform, Probeable {
     var romstr = byteArrayToString(data);
     this.nes.loadROM(romstr);
     this.frameindex = 0;
+    this.installIntercepts();
+  }
+  installIntercepts() {
     // intercept bus calls, unless we did it already
-    if (!this.nes.mmap.haveProxied) {
-      var oldload = this.nes.mmap.load.bind(this.nes.mmap);
-      var oldwrite = this.nes.mmap.write.bind(this.nes.mmap);
-      //var oldregLoad = this.nes.mmap.regLoad.bind(this.nes.mmap);
-      //var oldregWrite = this.nes.mmap.regWrite.bind(this.nes.mmap);
-      this.nes.mmap.load = (addr) => {
+    var mmap = this.nes.mmap;
+    if (!mmap.haveProxied) {
+      var oldload = mmap.load.bind(mmap);
+      var oldwrite = mmap.write.bind(mmap);
+      //var oldregLoad = mmap.regLoad.bind(mmap);
+      //var oldregWrite = mmap.regWrite.bind(mmap);
+      mmap.load = (addr) => {
         var val = oldload(addr);
         this.probe.logRead(addr, val);
         return val;
       }
-      this.nes.mmap.write = (addr, val) => {
+      mmap.write = (addr, val) => {
         this.probe.logWrite(addr, val);
         oldwrite(addr, val);
       }
       /*
-      this.nes.mmap.regLoad = (addr) => {
+      mmap.regLoad = (addr) => {
         var val = oldregLoad(addr);
         this.probe.logIORead(addr, val);
         return val;
       }
-      this.nes.mmap.regWrite = (addr, val) => {
+      mmap.regWrite = (addr, val) => {
         this.probe.logIOWrite(addr, val);
         oldregWrite(addr, val);
       }
       */
-      this.nes.mmap.haveProxied = true;
+      mmap.haveProxied = true;
+    }
+    var ppu = this.nes.ppu;
+    if (!ppu.haveProxied) {
+      var old_endScanline = ppu.endScanline.bind(ppu);
+      var old_startFrame = ppu.startFrame.bind(ppu);
+      var old_writeMem = ppu.writeMem.bind(ppu);
+      ppu.endScanline = () => {
+        old_endScanline();
+        this.probe.logNewScanline();
+      }
+      ppu.startFrame = () => {
+        old_startFrame();
+        this.probe.logNewFrame();
+      }
+      ppu.writeMem = (a,v) => {
+        old_writeMem(a,v);
+        this.probe.logVRAMWrite(a,v);
+      }
     }
   }
   newCodeAnalyzer() {
@@ -261,6 +266,7 @@ class JSNESPlatform extends Base6502Platform implements Platform, Probeable {
   reset() {
     //this.nes.cpu.reset(); // doesn't work right, crashes
     this.nes.cpu.requestIrq(this.nes.cpu.IRQ_RESET);
+    this.installIntercepts();
   }
   isRunning() {
     return this.timer.isRunning();
@@ -312,6 +318,7 @@ class JSNESPlatform extends Base6502Platform implements Platform, Probeable {
     this.nes.ppu.spriteMem = state.ppu.spriteMem.slice(0);
     this.loadControlsState(state.ctrl);
     //$.extend(this.nes, state);
+    this.installIntercepts();
   }
   saveControlsState() {
     return {
@@ -324,10 +331,10 @@ class JSNESPlatform extends Base6502Platform implements Platform, Probeable {
     this.nes.controllers[2].state = state.c2;
   }
   readAddress(addr) {
-    return this.nes.cpu.mem[addr] & 0xff;
+    return this.nes.cpu.mem[addr];
   }
   readVRAMAddress(addr : number) : number {
-    return this.nes.ppu.vramMem[addr & 0x7fff] & 0xff;
+    return this.nes.ppu.vramMem[addr];
   }
   copy6502REGvars(c) {
     c.T = 0;
diff --git a/src/recorder.ts b/src/recorder.ts
index 6d505540..1d1bae25 100644
--- a/src/recorder.ts
+++ b/src/recorder.ts
@@ -215,7 +215,6 @@ export class ProbeRecorder implements ProbeAll {
   }
   start() {
     this.m.connectProbe(this);
-    this.reset();
   }
   stop() {
     this.m.connectProbe(null);
diff --git a/src/ui.ts b/src/ui.ts
index ea84a5ee..3480e563 100644
--- a/src/ui.ts
+++ b/src/ui.ts
@@ -250,14 +250,11 @@ function refreshWindowList() {
     });
   }
   if (platform.startProbing) {
-    addWindowItem("#eventprobe", "Event Probe", () => {
-      return new Views.EventProbeView();
-    });
-    addWindowItem("#memheatmap", "Memory Heatmap", () => {
+    addWindowItem("#memheatmap", "Memory Probe", () => {
       return new Views.AddressHeatMapView();
     });
     // TODO: only if raster
-    addWindowItem("#crtheatmap", "Screen Heatmap", () => {
+    addWindowItem("#crtheatmap", "CRT Probe", () => {
       return new Views.RasterPCHeatMapView();
     });
   }
diff --git a/src/views.ts b/src/views.ts
index f22320a7..cf948b58 100644
--- a/src/views.ts
+++ b/src/views.ts
@@ -1,5 +1,4 @@
 
-import $ = require("jquery");
 //import CodeMirror = require("codemirror");
 import { SourceFile, WorkerError, Segment, FileData } from "./workertypes";
 import { Platform, EmuState, ProfilerOutput, lookupSymbol, BaseDebugPlatform } from "./baseplatform";
@@ -536,6 +535,7 @@ export class MemoryView implements ProjectView {
   maindiv : HTMLElement;
   static IGNORE_SYMS = {s__INITIALIZER:true, /* s__GSINIT:true, */ _color_prom:true};
   recreateOnResize = true;
+  totalRows = 0x1400;
 
   createDiv(parent : HTMLElement) {
     var div = document.createElement('div');
@@ -550,7 +550,7 @@ export class MemoryView implements ProjectView {
       w: $(workspace).width(),
       h: $(workspace).height(),
       itemHeight: getVisibleEditorLineHeight(),
-      totalRows: 0x1400,
+      totalRows: this.totalRows,
       generatorFn: (row : number) => {
         var s = this.getMemoryLineAt(row);
         var linediv = document.createElement("div");
@@ -695,6 +695,7 @@ export class MemoryView implements ProjectView {
 }
 
 export class VRAMMemoryView extends MemoryView {
+  totalRows = 0x800;
   readAddress(n : number) {
     return platform.readVRAMAddress(n);
   }
@@ -959,6 +960,15 @@ abstract class ProbeViewBase {
     return this.maindiv = div;
   }
 
+  addr2str(addr : number) : string {
+    var _addr2sym = (platform.debugSymbols && platform.debugSymbols.addr2symbol) || {};
+    var sym = _addr2sym[addr];
+    if (typeof sym === 'string')
+      return '$' + hex(addr) + ' (' + sym + ')';
+    else
+      return '$' + hex(addr);
+  }
+
   initCanvas() {
   }
   
@@ -982,6 +992,7 @@ abstract class ProbeViewBase {
   setVisible(showing : boolean) : void {
     if (showing) {
       this.probe = platform.startProbing();
+      this.tick();
     } else {
       platform.stopProbing();
       this.probe = null;
@@ -989,14 +1000,6 @@ abstract class ProbeViewBase {
   }
 
   clear() {
-    var ctx = this.ctx;
-    //ctx.globalCompositeOperation = 'source-over';
-    //ctx.globalAlpha = 1.0;
-    //ctx.fillStyle = '#000000';
-    //ctx.fillRect(0, 0, this.canvas.width, this.canvas.height);
-    ctx.clearRect(0, 0, this.canvas.width, this.canvas.height);
-    ctx.globalAlpha = 1.0;
-    ctx.globalCompositeOperation = 'lighter';
   }
   
   redraw( eventfn:(op,addr,col,row) => void ) {
@@ -1020,23 +1023,8 @@ abstract class ProbeViewBase {
   }
 
   tick() {
-    var ctx = this.ctx;
     this.clear();
     this.redraw(this.drawEvent.bind(this));
-    if (this.probe && !this.probe.singleFrame) this.probe.reset();
-  }
-  
-  setContextForOp(op) {
-      var ctx = this.ctx;
-      switch (op) {
-        //case ProbeFlags.EXECUTE:	ctx.fillStyle = "green"; break;
-        //case ProbeFlags.MEM_READ:	ctx.fillStyle = "#7f7f7f"; break;
-        case ProbeFlags.MEM_WRITE:	ctx.fillStyle = "red"; break;
-        case ProbeFlags.IO_READ:	ctx.fillStyle = "green"; break;
-        case ProbeFlags.IO_WRITE:	ctx.fillStyle = "magenta"; break;
-        case ProbeFlags.INTERRUPT:	ctx.fillStyle = "yellow"; break;
-        default:			ctx.fillStyle = "blue"; break;
-      }
   }
   
   abstract drawEvent(op, addr, col, row);
@@ -1067,13 +1055,13 @@ abstract class ProbeBitmapViewBase extends ProbeViewBase {
     y = y|0;
     var s = "";
     this.redraw( (op,addr,col,row) => {
-      if (col == x && row == y) {
+      if (y == row && x == col) {
          s += "\n" + this.opToString(op, addr);
       }
     } );
-    return '(' + x + ',' + y + ')' + s;
-  }  
-  opToString(op:number, addr:number) {
+    return 'X: ' + x + '  Y: ' + y + ' ' + s;
+  }
+  opToString(op:number, addr?:number) {
     var s = "";
     switch (op) {
       case ProbeFlags.EXECUTE:		s = "Exec"; break;
@@ -1086,7 +1074,7 @@ abstract class ProbeBitmapViewBase extends ProbeViewBase {
       case ProbeFlags.INTERRUPT:	s = "Interrupt"; break;
       default:				s = ""; break;
     }
-    return s + " $" + hex(addr);
+    return typeof addr == 'number' ? s + " " + this.addr2str(addr) : s;
   }
 
   refresh() {
@@ -1107,9 +1095,9 @@ abstract class ProbeBitmapViewBase extends ProbeViewBase {
       case ProbeFlags.MEM_WRITE:	return 0x010180;
       case ProbeFlags.IO_READ:		return 0x018080;
       case ProbeFlags.IO_WRITE:		return 0xc00180;
-      case ProbeFlags.VRAM_READ:	return 0x018080;
-      case ProbeFlags.VRAM_WRITE:	return 0xc00180;
-      case ProbeFlags.INTERRUPT:	return 0xc0c001;
+      case ProbeFlags.VRAM_READ:	return 0x808001;
+      case ProbeFlags.VRAM_WRITE:	return 0x4080c0;
+      case ProbeFlags.INTERRUPT:	return 0xcfcfcf;
       default:				return 0;
     }
   }
@@ -1141,9 +1129,22 @@ export class AddressHeatMapView extends ProbeBitmapViewBase implements ProjectVi
   }
   
   getTooltipText(x:number, y:number) : string {
-    var addr = (x & 0xff) + (y << 8);
-    return '$'+hex(addr);
-  }  
+    var a = (x & 0xff) + (y << 8);
+    var s = this.addr2str(a);
+    var pc = -1;
+    var already = {};
+    this.redraw( (op,addr,col,row) => {
+      if (op == ProbeFlags.EXECUTE) {
+        pc = addr;
+      }
+      var key = op|pc;
+      if (addr == a && !already[key]) {
+         s += "\nPC " + this.addr2str(pc) + " " + this.opToString(op);
+         already[key] = 1;
+      }
+    } );
+    return s;
+  }
 }
 
 /*
@@ -1175,68 +1176,6 @@ export class RasterPCHeatMapView extends ProbeBitmapViewBase implements ProjectV
   
 }
 
-export class EventProbeView extends ProbeViewBase implements ProjectView {
-  symcache : Map<number,symbol> = new Map();
-  xmax : number = 1;
-  ymax : number = 1;
-  lastsym : string;
-  xx : number;
-  yy : number;
-
-  createDiv(parent : HTMLElement) {
-    return this.createCanvas( parent, $(parent).width(), $(parent).height() );
-  }
-
-  drawEvent(op, addr, col, row) {
-    var ctx = this.ctx;
-    this.xmax = Math.max(this.xmax, col);
-    this.ymax = Math.max(this.ymax, row);
-    var xscale = this.canvas.width / this.xmax; // TODO: pixels
-    var yscale = (this.canvas.height - 12) / this.ymax; // TODO: lines
-    var x = col * xscale;
-    var y = row * yscale;
-    x = this.xx;
-    y = this.yy = Math.max(this.yy, y);
-    var sym = this.getSymbol(addr);
-    if (!sym && op == ProbeFlags.IO_WRITE) sym = hex(addr,4);
-    //TODO if (!sym && op == ProbeFlags.IO_READ)  sym = hex(addr,4);
-    if (sym && sym != this.lastsym) {
-      this.setContextForOp(op);
-      ctx.textAlign = 'left'; //ctx.textAlign = (x < this.canvas.width/2) ? 'left' : 'right';
-      ctx.textBaseline = 'top'; //ctx.textBaseline = (y < this.canvas.height/2) ? 'top' : 'bottom';
-      var mt = ctx.measureText(sym);
-      if (x + mt.width > this.canvas.width) {
-        x = 0;
-        y += 12;
-      }
-      ctx.fillText(sym, x, y);
-      this.xx = x + mt.width + 10;
-      this.yy = y;
-      this.lastsym = sym;
-    }
-  }
-
-  getSymbol(addr:number) : string {
-    var sym = this.symcache[addr];
-    if (!sym) {
-      sym = lookupSymbol(platform, addr, false);
-      this.symcache[addr] = sym;
-    }
-    return sym;
-  }
-
-  tick() {
-    this.xx = this.yy = 0;
-    this.lastsym = '';
-    super.tick();
-  }
-
-  refresh() {
-    this.tick();
-    this.symcache.clear();
-  }
-}
-
 ///
 
 export class AssetEditorView implements ProjectView, pixed.EditorContext {
diff --git a/src/worker/workermain.ts b/src/worker/workermain.ts
index 45d45489..e94d5537 100644
--- a/src/worker/workermain.ts
+++ b/src/worker/workermain.ts
@@ -974,6 +974,7 @@ function linkLD65(step:BuildStep) {
     }
     // build segment map
     var seg_re = /^__(\w+)_SIZE__$/;
+    // TODO: move to Platform class
     var segments = [];
     segments.push({name:'CPU Stack',start:0x100,size:0x100,type:'ram'});
     segments.push({name:'CPU Vectors',start:0xfffa,size:0x6,type:'rom'});