         # starts with a cell or output marker and is not already marked.
         # If not marked, mark it appropriately, and possibly process any
         # changes to that line.
-        cm = @codemirror
+        @_process_sage_updates(@codemirror, start)
+        if @editor._split_view
+            @_process_sage_updates(@editor.codemirror1, start)
+
+    _process_sage_updates: (cm, start) =>
+
         if not start?
             start = 0
 

            else if x[0] == MARKERS.output
                marks = cm.findMarksAt({line:line, ch:1})
                if marks.length == 0
                    @mark_output_line(line)
                mark = cm.findMarksAt({line:line, ch:1})[0]
                uuid = cm.getRange({line:line,ch:1}, {line:line,ch:37})
                if mark.uuid != uuid # uuid changed -- completely new output
                    #console.log("uuid change: new x = ", x)
                    mark.processed = 38
                    mark.uuid = uuid
                    @elt_at_mark(mark).html('')
                if mark.processed < x.length
                    #console.log("length change; x = ", x)
                    # new output to process
                    t = x.slice(mark.processed, x.length-1)


            if x[0] == MARKERS.cell
                marks = cm.findMarksAt({line:line, ch:1})
                if not marks? or marks.length == 0
                    @mark_cell_start(cm, line)
                else
                    first = true
                    for mark in marks
