diff --git a/doc/notes.txt b/doc/notes.txt
index e7985340..6faf84ee 100644
--- a/doc/notes.txt
+++ b/doc/notes.txt
@@ -16,13 +16,13 @@ TODO:
 - case sensisitvity looking for mismatch variables
 - remove pulldown when no preset?
 - can't step after reset (or when funky frame; TIA frame is out of sync)
-- break on BRK/illegal opcode?
+- break on BRK/illegal opcode? (or warnings?)
 - skeleton for each platform/tool (check?)
 - disassembler/debugger
 - multiple breakpoints, expression breakpoints
 - current exec. pos in gutter
 - cc65: parse listing
-- faster Z80 compile
-- projects w/ multiple files, navigation (need refactor UI)
+- faster Z80 compile (maybe split up files?)
+- projects w/ multiple files, navigation (need refactor UI, backend)
 - nes: tools (nesst, tiled) https://shiru.untergrund.net/software.shtml
 
diff --git a/src/ui.js b/src/ui.js
index dc45d105..0dff96de 100644
--- a/src/ui.js
+++ b/src/ui.js
@@ -582,13 +582,33 @@ worker.onmessage = function(e) {
   setCompileOutput(e.data);
 }
 
-function setCurrentLine(line) {
-  editor.setSelection({line:line,ch:0}, {line:line-1,ch:0}, {scroll:true});
-}
-
+var currentDebugLine;
 var lastDebugInfo;
 var lastDebugState;
 
+function setCurrentLine(line) {
+  function addCurrentMarker(line) {
+    var div = document.createElement("div");
+    div.style.color = '#66ffff'; // TODO
+    div.appendChild(document.createTextNode("\u25b6"));
+    editor.setGutterMarker(line, "gutter-info", div);
+  }
+  clearCurrentLine();
+  if (line>0) {
+    addCurrentMarker(line-1);
+    editor.setSelection({line:line,ch:0}, {line:line-1,ch:0}, {scroll:true});
+    currentDebugLine = line;
+  }
+}
+
+function clearCurrentLine() {
+  if (currentDebugLine) {
+    editor.clearGutter("gutter-info");
+    editor.setSelection(editor.getCursor()); // TODO??
+    currentDebugLine = 0;
+  }
+}
+
 function showMemory(state) {
   var s = state && platform.cpuStateToLongString && platform.cpuStateToLongString(state.c);
   if (s) {
@@ -654,8 +674,9 @@ function _resume() {
 
 function resume() {
   clearBreakpoint();
-  if (! platform.isRunning() )
-    editor.setSelection(editor.getCursor()); // TODO??
+  if (! platform.isRunning() ) {
+    clearCurrentLine();
+  }
   _resume();
   userPaused = false;
 }