diff --git a/index.html b/index.html
index 470a263..d5b2c6c 100644
--- a/index.html
+++ b/index.html
@@ -131,7 +131,6 @@
 <script src="js/ext/util.js"></script>
 <script src="js/ext/unicode.js"></script>
 <script src="js/ext/color.js"></script>
-<script src="js/undo.js"></script>
 <script src="js/clipboard.js"></script>
 <script src="js/ext/upload.js"></script>
 <script src="js/ext/user.js"></script>
diff --git a/js/matrix.js b/js/matrix.js
index 034c551..8520c2a 100644
--- a/js/matrix.js
+++ b/js/matrix.js
@@ -320,3 +320,231 @@ Matrix.prototype.irssi = function(opts){
   }
   return txt
 }
+
+var undo = (function(){
+
+var max_states = 200;
+
+// undotimetotal = 0;
+
+var stack = {undo: [], redo: []};
+var current_undo = null;
+var dom = {undo: undo_el, redo: redo_el};
+dom.undo.is_visible = dom.redo.is_visible = false
+
+var LexState = function(lex){
+  this.fg = lex.fg;
+  this.bg = lex.bg;
+  this.char = lex.char;
+  this.opacity = lex.opacity;
+};
+
+var update_dom_visibility = function(type){
+  var el = dom[type]
+  if (el.is_visible){
+    if (stack[type].length === 0) {
+      el.classList.add('hidden')
+      el.is_visible = false
+    }
+  } else if (stack[type].length > 0){
+    el.classList.remove('hidden')
+    el.is_visible = true
+  }
+}
+var update_dom = function(){
+  update_dom_visibility('undo')
+  update_dom_visibility('redo')
+}
+
+// state is an undo or redo state that might contain these props
+// {  lexs: {'0,0': LexState, ...},    // for sparse lex changes (eg brush, fill)
+//    focus: {x:, y: },
+//    size: {w:, h: },
+//    rects: [{x:, y:, w:, h:, lexs: [LexState, ...]}, ...]
+// }
+var new_state = function(){
+  var state = {lexs:{}};
+  save_focus(canvas.focus_x, canvas.focus_y, state)
+  return state
+}
+var new_redo = function(){
+  return new_state()
+}
+var new_undo = function(){
+  current_undo = new_state()
+  stack.redo = []
+  stack.undo.push(current_undo)
+  if (stack.undo.length > max_states) stack.undo.shift();
+  update_dom()
+  return current_undo
+}
+
+var save_focus = function(x, y, state){
+  state = state || current_undo
+  state.focus = {x:x, y:y}
+}
+var save_size = function(w, h, state){
+  state = state || current_undo
+  state.size = {w:w, h:h};
+}
+// the reason for stringifying the x y coords is so that each
+// coordinate is saved only once in an undo state.
+// otherwise there would be problems with, eg, a brush stroke 
+// that passed over the same grid cell twice. 
+var save_lex = function(x, y, lex, state){
+  // var start = Date.now()
+  state = state || current_undo
+  var lexs = state.lexs;
+  var xy = x + "," + y;
+  if (xy in lexs) return;
+  lexs[xy] = new LexState(lex)
+  // undotimetotal += Date.now() - start
+}
+var save_focused_lex = function(state){
+  state = state || current_undo
+  var x = canvas.focus_x
+  var y = canvas.focus_y
+  save_lex(x, y, canvas.aa[y][x], state)
+}
+var save_rect = function(xpos, ypos, w, h, state){
+  if (w === 0 || h === 0) return;
+  state = state || current_undo;
+  state.rects = state.rects || []
+  var aa = canvas.aa;
+  var rect = {x: xpos, y: ypos, w: w, h: h, lexs: []}
+  var lexs = rect.lexs
+  var xlen = xpos + w
+  var ylen = ypos + h
+  for (var y = ypos; y < ylen; y++){
+    var aay = aa[y]
+    for (var x = xpos; x < xlen; x++){
+      lexs.push(new LexState(aay[x]))
+    }
+  }
+  state.rects.push(rect)
+}
+var save_resize = function(w, h, old_w, old_h, state){
+  state = state || current_undo
+  save_size(old_w, old_h, state)
+  if (old_w > w){
+    // .---XX
+    // |   XX
+    // |___XX
+    save_rect(w, 0, old_w - w, old_h, state)
+    if (old_h > h){
+      // .----.
+      // |    |
+      // XXXX_|
+      save_rect(0, h, w, old_h - h, state)
+    }
+  } else if (old_h > h){
+    // .----.
+    // |    |
+    // XXXXXX
+    save_rect(0, h, old_w, old_h - h, state)
+  }
+}
+
+var restore_state = function(state){
+  // all redo states will have a cached undo state on them
+  // an undo state might have a cached redo state
+  // if it doesn't have one, generate one
+  var make_redo = ! ('redo' in state || 'undo' in state);
+  var aa = canvas.aa
+  var lex, lexs;
+
+  if (make_redo){
+    state.redo = new_redo()
+
+    // copy saved rects that intersect with current canvas size
+    // important to do this before resizing canvas
+    if ('rects' in state){
+      for (var ri=0, rect; rect=state.rects[ri]; ri++){
+        if (rect.x >= canvas.w ||
+            rect.y >= canvas.h) continue;
+        var w = Math.min(rect.w, canvas.w - rect.x)
+        var h = Math.min(rect.h, canvas.h - rect.y)
+        save_rect(rect.x, rect.y, w, h, state.redo)
+      }
+    }
+    if ('size' in state){
+      save_resize(state.size.w, state.size.h, canvas.w, canvas.h, state.redo)
+    }
+  }
+
+  if ('size' in state){
+    canvas.resize(state.size.w, state.size.h, true);
+  }
+
+  if ('rects' in state){
+    for (var ri=0, rect; rect=state.rects[ri]; ri++){
+      lexs = rect.lexs
+      for (var li=0; lex=lexs[li]; li++){
+        var x = (li % rect.w) + rect.x
+        var y = ((li / rect.w)|0) + rect.y
+        aa[y][x].assign(lex)
+      }
+    }
+  }
+
+  lexs = state.lexs
+  for (var key in lexs){
+    var xy = key.split(',');
+    lex = aa[xy[1]][xy[0]]
+    if (make_redo)
+      save_lex(xy[0], xy[1], lex, state.redo)
+    lex.assign(lexs[key])
+  }
+
+  if ('focus' in state){
+    canvas.focus_x = state.focus.x
+    canvas.focus_y = state.focus.y
+    if (current_canvas === canvas){
+      canvas.focus()
+    }
+  }
+}
+
+var undo = function(){
+  var state = stack.undo.pop();
+  if (!state) return;
+
+  restore_state(state)
+  
+  // now take the applied undo state and store it on the redo state
+  // and push the redo state to the redo stack
+  state.redo.undo = state
+  stack.redo.push(state.redo)
+  delete state.redo
+
+  update_dom()
+}
+
+var redo = function(){
+  var state = stack.redo.pop();
+  if (!state) return;
+  
+  restore_state(state)
+
+  state.undo.redo = state
+  stack.undo.push(state.undo)
+  delete state.undo
+
+  update_dom()
+}
+
+return {
+  stack: stack,
+  new: new_undo,
+//  new_redo: new_redo,
+  save_focus: save_focus,
+  save_size: save_size,
+  save_lex: save_lex,
+  save_focused_lex: save_focused_lex,
+  save_rect: save_rect,
+  save_resize: save_resize,
+  undo: undo,
+  redo: redo
+}
+
+})()
diff --git a/js/undo.js b/js/undo.js
deleted file mode 100644
index 35a27d9..0000000
--- a/js/undo.js
+++ /dev/null
@@ -1,227 +0,0 @@
-var undo = (function(){
-
-var max_states = 200;
-
-// undotimetotal = 0;
-
-var stack = {undo: [], redo: []};
-var current_undo = null;
-var dom = {undo: undo_el, redo: redo_el};
-dom.undo.is_visible = dom.redo.is_visible = false
-
-var LexState = function(lex){
-  this.fg = lex.fg;
-  this.bg = lex.bg;
-  this.char = lex.char;
-  this.opacity = lex.opacity;
-};
-
-var update_dom_visibility = function(type){
-  var el = dom[type]
-  if (el.is_visible){
-    if (stack[type].length === 0) {
-      el.classList.add('hidden')
-      el.is_visible = false
-    }
-  } else if (stack[type].length > 0){
-    el.classList.remove('hidden')
-    el.is_visible = true
-  }
-}
-var update_dom = function(){
-  update_dom_visibility('undo')
-  update_dom_visibility('redo')
-}
-
-// state is an undo or redo state that might contain these props
-// {  lexs: {'0,0': LexState, ...},    // for sparse lex changes (eg brush, fill)
-//    focus: {x:, y: },
-//    size: {w:, h: },
-//    rects: [{x:, y:, w:, h:, lexs: [LexState, ...]}, ...]
-// }
-var new_state = function(){
-  var state = {lexs:{}};
-  save_focus(canvas.focus_x, canvas.focus_y, state)
-  return state
-}
-var new_redo = function(){
-  return new_state()
-}
-var new_undo = function(){
-  current_undo = new_state()
-  stack.redo = []
-  stack.undo.push(current_undo)
-  if (stack.undo.length > max_states) stack.undo.shift();
-  update_dom()
-  return current_undo
-}
-
-var save_focus = function(x, y, state){
-  state = state || current_undo
-  state.focus = {x:x, y:y}
-}
-var save_size = function(w, h, state){
-  state = state || current_undo
-  state.size = {w:w, h:h};
-}
-// the reason for stringifying the x y coords is so that each
-// coordinate is saved only once in an undo state.
-// otherwise there would be problems with, eg, a brush stroke 
-// that passed over the same grid cell twice. 
-var save_lex = function(x, y, lex, state){
-  // var start = Date.now()
-  state = state || current_undo
-  var lexs = state.lexs;
-  var xy = x + "," + y;
-  if (xy in lexs) return;
-  lexs[xy] = new LexState(lex)
-  // undotimetotal += Date.now() - start
-}
-var save_focused_lex = function(state){
-  state = state || current_undo
-  var x = canvas.focus_x
-  var y = canvas.focus_y
-  save_lex(x, y, canvas.aa[y][x], state)
-}
-var save_rect = function(xpos, ypos, w, h, state){
-  if (w === 0 || h === 0) return;
-  state = state || current_undo;
-  state.rects = state.rects || []
-  var aa = canvas.aa;
-  var rect = {x: xpos, y: ypos, w: w, h: h, lexs: []}
-  var lexs = rect.lexs
-  var xlen = xpos + w
-  var ylen = ypos + h
-  for (var y = ypos; y < ylen; y++){
-    var aay = aa[y]
-    for (var x = xpos; x < xlen; x++){
-      lexs.push(new LexState(aay[x]))
-    }
-  }
-  state.rects.push(rect)
-}
-var save_resize = function(w, h, old_w, old_h, state){
-  state = state || current_undo
-  save_size(old_w, old_h, state)
-  if (old_w > w){
-    // .---XX
-    // |   XX
-    // |___XX
-    save_rect(w, 0, old_w - w, old_h, state)
-    if (old_h > h){
-      // .----.
-      // |    |
-      // XXXX_|
-      save_rect(0, h, w, old_h - h, state)
-    }
-  } else if (old_h > h){
-    // .----.
-    // |    |
-    // XXXXXX
-    save_rect(0, h, old_w, old_h - h, state)
-  }
-}
-
-var restore_state = function(state){
-  // all redo states will have a cached undo state on them
-  // an undo state might have a cached redo state
-  // if it doesn't have one, generate one
-  var make_redo = ! ('redo' in state || 'undo' in state);
-  var aa = canvas.aa
-  var lex, lexs;
-
-  if (make_redo){
-    state.redo = new_redo()
-
-    // copy saved rects that intersect with current canvas size
-    // important to do this before resizing canvas
-    if ('rects' in state){
-      for (var ri=0, rect; rect=state.rects[ri]; ri++){
-        if (rect.x >= canvas.w ||
-            rect.y >= canvas.h) continue;
-        var w = Math.min(rect.w, canvas.w - rect.x)
-        var h = Math.min(rect.h, canvas.h - rect.y)
-        save_rect(rect.x, rect.y, w, h, state.redo)
-      }
-    }
-    if ('size' in state){
-      save_resize(state.size.w, state.size.h, canvas.w, canvas.h, state.redo)
-    }
-  }
-
-  if ('size' in state){
-    canvas.resize(state.size.w, state.size.h, true);
-  }
-
-  if ('rects' in state){
-    for (var ri=0, rect; rect=state.rects[ri]; ri++){
-      lexs = rect.lexs
-      for (var li=0; lex=lexs[li]; li++){
-        var x = (li % rect.w) + rect.x
-        var y = ((li / rect.w)|0) + rect.y
-        aa[y][x].assign(lex)
-      }
-    }
-  }
-
-  lexs = state.lexs
-  for (var key in lexs){
-    var xy = key.split(',');
-    lex = aa[xy[1]][xy[0]]
-    if (make_redo)
-      save_lex(xy[0], xy[1], lex, state.redo)
-    lex.assign(lexs[key])
-  }
-
-  if ('focus' in state){
-    canvas.focus_x = state.focus.x
-    canvas.focus_y = state.focus.y
-    if (current_canvas === canvas){
-      canvas.focus()
-    }
-  }
-}
-
-var undo = function(){
-  var state = stack.undo.pop();
-  if (!state) return;
-
-  restore_state(state)
-  
-  // now take the applied undo state and store it on the redo state
-  // and push the redo state to the redo stack
-  state.redo.undo = state
-  stack.redo.push(state.redo)
-  delete state.redo
-
-  update_dom()
-}
-
-var redo = function(){
-  var state = stack.redo.pop();
-  if (!state) return;
-  
-  restore_state(state)
-
-  state.undo.redo = state
-  stack.undo.push(state.undo)
-  delete state.undo
-
-  update_dom()
-}
-
-return {
-  stack: stack,
-  new: new_undo,
-//  new_redo: new_redo,
-  save_focus: save_focus,
-  save_size: save_size,
-  save_lex: save_lex,
-  save_focused_lex: save_focused_lex,
-  save_rect: save_rect,
-  save_resize: save_resize,
-  undo: undo,
-  redo: redo
-}
-
-})()