/**
  * Post a message to the assembler display
  *
  * @param message String to append to assembler display text
  */
 public void postMarsMessage(String message) {
   assemble.append(message);
   // can do some crude cutting here.  If the document gets "very large",
   // let's cut off the oldest text. This will limit scrolling but the limit
   // can be set reasonably high.
   if (assemble.getDocument().getLength() > MAXIMUM_SCROLLED_CHARACTERS) {
     try {
       assemble.getDocument().remove(0, NUMBER_OF_CHARACTERS_TO_CUT);
     } catch (BadLocationException ble) {
       // only if NUMBER_OF_CHARACTERS_TO_CUT > MAXIMUM_SCROLLED_CHARACTERS
     }
   }
   assemble.setCaretPosition(assemble.getDocument().getLength());
   setSelectedComponent(assembleTab);
 }