This will simply enter the 128's ML monitor. To get back to THE SERVANT you may enter 'G C8000' for a full restart (will initialize THE SERVANT's colors, and function key definitions), or 'G C8009' if you prefer to retain the colors and function keys currently in use. (If THE SERVANT is mounted externally, the respective commands are 'G D8000' and 'G D8009'.)
