Intellivision was a game console system designed by Mattel Electronics in 1979 to compete against Atari, Colecovision and Magnavox's Odyssey2. Three years later, the company unveiled Intellivoice, a module that attached to the cartridge port of the Intellivision. When using special voice-enhanced games, the Intellivision could talk. Five games were developed to take advantage of the unit's capabilities: Space Spartans, B-17 Bomber, Tron Solar Sailor, Bomb Squad and World Series Major League Baseball.