The Odyssey is the first home video game console, released in September of 1972 by Magnavox and was retailed for $99.99 (though when purchased with a Magnavox television, it cost only $50. It was called the Brown Box during development. It ran on either 6 C-cell batteries or a 9-volt AC adapter. The Odyssey did not use a CPU; the cartridges, called "circuit cards", altered the machine's signal path instead. This changed the light output of the television screen, creating the appearance of a game, but it did not allow for music to be played.