Under contract from the U.S. Military, Matrox produced a combination computer/LaserDisc player for instructional purposes. The computer was a 286, the LaserDisc player only capable of reading the analog audio tracks. Together they weighed 43 lb (20 kg) and sturdy handles were provided in case two people were required to lift the unit. The computer controlled the player via a 25-pin serial port at the back of the player and a ribbon cable connected to a proprietary port on the motherboard. Many of these were sold as surplus by the military during the 1990s, often without the controller software. Nevertheless, it is possible to control the unit by removing the ribbon cable and connecting a serial cable directly from the computer's serial port to the port on the LaserDisc player.