Intellivision

The Intellivoice Voice Synthesis Module was an adapter for the Intellivision, Mattel's home gaming console, that utilized a voice synthesizer to generate audible speech. The Intellivoice was a large, brown cartridge that plugged into the Intellivision's side-mounted cartridge slot; games specifically designed for the device could then be inserted into a slot provided on the right-hand side of the module. An International version of the Intellivoice was planned, but never released. The Intellivoice was discontinued in 1983 due to poor sales, with only four titles released with support for the device.