diff --git a/expert.html b/expert.html
index 6653f31..0b897d6 100644
--- a/expert.html
+++ b/expert.html
@@ -122,10 +122,12 @@ $().ready(function(){
 
    <div id="tracingdiv">
 	<div id="expertControlPanel">
-	  <form>
+	  <form action="javascript:updateLogList()">
 	  <input type="button" value="Trace more" onclick="updateLoglevel(++loglevel)" />
 	  <input type="button" value="Trace less" onclick="updateLoglevel(--loglevel)" />
-	  <input type="button" value="Clear Log"  onclick="updateLoglevel(loglevel)" />
+	  <input type="button" value="Trace these too:" onclick="updateLogList()" />
+            <input type="text" id="LogThese" name="LogThese" value="" />
+	  <input type="button" value="Clear Log" onclick="updateLoglevel(loglevel)" />
 	  </form>
 	  <br />
 	</div>
diff --git a/expertWires.js b/expertWires.js
index 763c337..621637e 100644
--- a/expertWires.js
+++ b/expertWires.js
@@ -1,5 +1,5 @@
 /*
- Copyright (c) 2010 Brian Silverman, Barry Silverman
+ Copyright (c) 2010 Brian Silverman, Barry Silverman, Ed Spittles
 
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
@@ -101,6 +101,7 @@ function setup_part3(){
 function setup_part4(){
 	setupTable();
 	setupNodeNameList();
+	logThese=signalSet(loglevel);
 	loadProgram();
 	if(noSimulation){
 		running=undefined;
@@ -293,7 +294,8 @@ function handleClick(e){
 
 function updateLoglevel(value){
 	loglevel = value;
-	initLogbox(signalSet(loglevel));
+	logThese = signalSet(loglevel);
+	initLogbox(logThese);
 }
 
 function updateExpertMode(isOn){
diff --git a/macros.js b/macros.js
index 2197a4f..657db19 100644
--- a/macros.js
+++ b/macros.js
@@ -25,6 +25,17 @@ var cycle = 0;
 var trace = Array();
 var logstream = Array();
 var running = false;
+var logThese=[];
+var presetLogLists=[
+		['cycle'],
+		['ab','db','rw','sync','pc','a','x','y','s','p'],
+		['ir','tcstate','pd'],
+		['adl','adh','sb','alu'],
+		['alucin','alua','alub','alucout','aluvout','dasb'],
+		['plaOutputs'],
+		['idb','dor'],
+		['irq','nmi','res'],
+	];
 
 function loadProgram(){
 	// a moderate size of static testprogram might be loaded
@@ -146,32 +157,32 @@ function initChip(){
 	refresh();
 	cycle = 0;
 	trace = Array();
-	initLogbox(signalSet(loglevel));
+	initLogbox(logThese);
 	chipStatus();
 	if(ctrace)console.log('initChip done after', now()-start);
 }
 
-var logThese=[
-		['cycle'],
-		['ab','db','rw','sync','pc','a','x','y','s','p'],
-		['ir','tcstate','pd'],
-		['adl','adh','sb','alu'],
-		['alucin','alua','alub','alucout','aluvout','dasb'],
-		['plaOutputs'],
-		['idb','dor'],
-		['irq','nmi','res'],
-	];
-
 function signalSet(n){
 	var signals=[];
-	for (var i=0; (i<=n)&&(i<logThese.length) ; i++){
-		for (var j=0; j<logThese[i].length; j++){
-			signals.push(logThese[i][j]);
+	for (var i=0; (i<=n)&&(i<presetLogLists.length) ; i++){
+		for (var j=0; j<presetLogLists[i].length; j++){
+			signals.push(presetLogLists[i][j]);
 		}
 	}
 	return signals;
 }
 
+function updateLogList(){
+	// user supplied a list of signals, which we append to the set defined by loglevel
+	logThese = signalSet(loglevel);
+	var tmplist = document.getElementById('LogThese').value.split(/[\s,]+/);
+	for(var i=0;i<tmplist.length;i++){
+		if(typeof nodes[nodenames[tmplist[i]]] != "undefined")
+			logThese.push(tmplist[i]);
+	}
+	initLogbox(logThese);
+}
+
 var traceChecksum='';
 var goldenChecksum;
 
@@ -383,7 +394,7 @@ function chipStatus(){
 		chk=" Chk:" + traceChecksum + ((traceChecksum==goldenChecksum)?" OK":" no match");
 	setStatus(machine1, machine2, "Hz: " + estimatedHz().toFixed(1) + chk);
 	if (loglevel>0) {
-		updateLogbox(signalSet(loglevel));
+		updateLogbox(logThese);
 	}
 	selectCell(ab);
 }