diff --git a/lib/ace/keyboard/emacs.js b/lib/ace/keyboard/emacs.js
index a09119ce..aee6ff4b 100644
--- a/lib/ace/keyboard/emacs.js
+++ b/lib/ace/keyboard/emacs.js
@@ -164,6 +164,7 @@ exports.handler.bindKey = function(key, command) {
 
 
 exports.handler.handleKeyboard = function(data, hashId, key, keyCode) {
+    // insertstring data.count times
     if (hashId == -1) {
         exports.setMarkMode(null);
         if (data.count) {
@@ -177,6 +178,8 @@ exports.handler.handleKeyboard = function(data, hashId, key, keyCode) {
         return;
 
     var modifier = eMods[hashId];
+
+    // CTRL + number / universalArgument for setting data.count
     if (modifier == "c-" || data.universalArgument) {
         var count = parseInt(key[key.length - 1]);
         if (count) {
@@ -186,42 +189,47 @@ exports.handler.handleKeyboard = function(data, hashId, key, keyCode) {
     }
     data.universalArgument = false;
 
-    if (modifier)
-        key = modifier + key;
+    // this.commandKeyBinding maps key specs like "c-p" (for CTRL + P) to
+    // command objects, for lookup key needs to include the modifier
+    if (modifier) key = modifier + key;
 
-    if (data.keyChain)
-        key = data.keyChain += " " + key;
+    // Key combos like CTRL+X H build up the data.keyChain
+    if (data.keyChain) key = data.keyChain += " " + key;
 
+    // Key combo prefixes get stored as "null" (String!) in this
+    // this.commmandKeyBinding. When encountered no command is invoked but we
+    // buld up data.keyChain
     var command = this.commmandKeyBinding[key];
     data.keyChain = command == "null" ? key : "";
 
-    if (!command)
-        return;
+    // there really is no command
+    if (!command) return;
 
-    if (command == "null")
-        return {command: "null"};
+    // we pass b/c of key combo or universalArgument
+    if (command === "null") return {command: "null"};
 
-    if (command == "universalArgument") {
+    if (command === "universalArgument") {
         data.universalArgument = true;
         return {command: "null"};
     }
 
-    if (typeof command != "string") {
-        var args = command.args;
-        command = command.command;
-        if (command == "goorselect") {
-            command = args[0];
-            if (exports.markMode()) {
-                command = args[1];
-            }
+    // lookup command
+    // TODO extract special handling of markmode
+    // TODO special case command.command is really unnecessary, remove
+    var args;
+    if (typeof command !== "string") {
+        args = command.args;
+        if (command.command) command = command.command;
+        if (command === "goorselect") {
+            command = exports.markMode() ? args[1] : args[0];
             args = null;
         }
     }
 
-    if (typeof command == "string") {
-        if (command == "insertstring" ||
-           command == "splitline" ||
-           command == "togglecomment") {
+    if (typeof command === "string") {
+        if (command === "insertstring" ||
+            command === "splitline" ||
+            command === "togglecomment") {
             exports.setMarkMode(null);
         }
         command = this.commands[command] || data.editor.commands.commands[command];