diff --git a/expert.css b/expert.css
index 8c7ca3e..3497785 100644
--- a/expert.css
+++ b/expert.css
@@ -138,6 +138,14 @@ a#linkHere{
  padding:2px;
 }
 
+textarea#consolebox{
+ font-family:courier,monospace;
+ border: 1px solid gray;
+ margin: 2px;
+ padding: 2px;
+ width: 80em;
+}
+
 div#logstreamscroller{
  overflow:auto;
 }
diff --git a/expert.html b/expert.html
index eeb5f08..0691c2e 100644
--- a/expert.html
+++ b/expert.html
@@ -124,7 +124,10 @@ $().ready(function(){
 </div> <!-- righttopdiv -->
 
    <div id="tracingdiv">
-	<div id="expertControlPanel">
+        <textarea id="consolebox">
+click here and type if your program handles input
+        </textarea>
+	<div id="expertControlPanel" tabindex="3">
 	  <form action="javascript:updateLogList()">
 	  <input type="button" value="Trace more" onclick="updateLoglevel(++loglevel)" />
 	  <input type="button" value="Trace less" onclick="updateLoglevel(--loglevel)" />
diff --git a/expertWires.js b/expertWires.js
index 087be7e..b0d8616 100644
--- a/expertWires.js
+++ b/expertWires.js
@@ -103,6 +103,7 @@ function setup_part4(){
 	setupNodeNameList();
 	logThese=signalSet(loglevel);
 	loadProgram();
+	setupConsole();
 	if(noSimulation){
 		stopChip();
 		running=undefined;
@@ -352,6 +353,14 @@ function setupExpertMode(isOn){
 		document.getElementById('layoutControlPanel').style.display = 'block';
 }
 
+var consolegetc;    // global variable to hold last keypress in the console area
+var consolebox;
+
+function setupConsole(){
+	consolebox=document.getElementById('consolebox');
+	consolebox.onkeypress=function(e){consolegetc=e.charCode;};
+}
+
 var chipsurround;
 
 function updateChipLayoutVisibility(isOn){
diff --git a/macros.js b/macros.js
index 8b922e0..5343d2e 100644
--- a/macros.js
+++ b/macros.js
@@ -209,24 +209,42 @@ function step(){
 }
 
 // triggers for breakpoints, watchpoints, input pin events
+// almost always are undefined when tested, so minimal impact on performance
 clockTriggers={};
+writeTriggers={};
+readTriggers={};
+fetchTriggers={};
+
+// example instruction tracing triggers
+// fetchTriggers[0x20]="console.log('0x'+readAddressBus().toString(16)+': JSR');";
+// fetchTriggers[0x60]="console.log('0x'+readAddressBus().toString(16)+': RTS');";
+// fetchTriggers[0x4c]="console.log('0x'+readAddressBus().toString(16)+': JMP');";
 
 // simulate a single clock phase with no update to graphics or trace
 function halfStep(){
 	var clk = isNodeHigh(nodenames['clk0']);
-	eval(clockTriggers[cycle]);  // usually undefined, no measurable performance loss
+	eval(clockTriggers[cycle]);
 	if (clk) {setLow('clk0'); handleBusRead(); } 
 	else {setHigh('clk0'); handleBusWrite();}
 }
 
 function handleBusRead(){
-	if(isNodeHigh(nodenames['rw'])) writeDataBus(mRead(readAddressBus()));
+	if(isNodeHigh(nodenames['rw'])){
+		var a = readAddressBus();
+		var d = eval(readTriggers[a]);
+		if(d == undefined)
+			d = mRead(readAddressBus());
+		if(isNodeHigh(nodenames['sync']))
+			eval(fetchTriggers[d]);
+		writeDataBus(d);
+	}
 }
 
 function handleBusWrite(){
 	if(!isNodeHigh(nodenames['rw'])){
 		var a = readAddressBus();
 		var d = readDataBus();
+		eval(writeTriggers[a]);
 		mWrite(a,d);
 		if(a<0x200) setCellValue(a,d);
 	}
@@ -455,8 +473,9 @@ function estimatedHz1(){
 	return prevHzEstimate1
 }
 
+var logbox;
 function initLogbox(names){
-	var logbox=document.getElementById('logstream');
+	logbox=document.getElementById('logstream');
 	if(logbox==null)return;
 
 	logStream = [];
@@ -469,9 +488,8 @@ var logboxAppend=true;
 // can append or prepend new states to the log table
 // when we reverse direction we need to reorder the log stream
 function updateLogDirection(){
-	logboxAppend=!logboxAppend;
-	var logbox=document.getElementById('logstream');
 	var loglines=[];
+	logboxAppend=!logboxAppend;
 	// the first element is the header so we can't reverse()
 	for (var i=1;i<logStream.length;i++) {
 		loglines.unshift(logStream[i]);
@@ -483,7 +501,6 @@ function updateLogDirection(){
 
 // update the table of signal values, by prepending or appending
 function updateLogbox(names){
-	var logbox=document.getElementById('logstream');
 	var signals=[];
 
 	for(i in names){