Ok. First snag. These games come with four boards: CPU (left), ROM (right), Sound, and Hook-Up. The CPU board that came with my game is actually for Stargate, Joust or Robotron. The CPU for the Defender system can only be used for Defender and isn’t compatible with the other machines. The reverse is also true, so I need to track down a Defender board. I can’t complain, I got these for free. Plus, I can get SOMETHING for the board, so I’m better off than I would have been without any boards.