The Adventurevision is a cartridge based tabletop video game system produced by Entex in 1982. The system has a rather unique built in LED display composed of a column of 40 LEDs and a spinning mirror that produced a display with a resolution of 150x40 pixels (Another product using this technique was produced by Nintendo in the mid 1990s : the Virtual Boy). Control is through a single multi-position joystick and two sets of four buttons, one on each side of the joystick, for ease of play by both left- and right-handed players. Four game cartridges can be stored in bays on top of the case. With hindsight this seems inspired as ultimately only four games were released. Three were arcade ports, Defender, Super Cobra and Turtles and the fourth was an Asteroids clone called Space Force. It's a very rare system (only 50,757 units were sold, and only 1000 each of the 3 separate games), and due to it's fragile nature and moving parts not many have survived. Boxed systems can sell for around 20 times the original retail price.