Ultimately, this fulfilled the original promises of turning the Intellivision into a computer, making it possible to write programs and store them to tape, and interfacing with a printer well enough to allow Mattel to claim that they had delivered the promised computer upgrade and stop the FTC's mounting fines. It even offered, via an additional sound chip (AY-3-8917) inside the ECS module and an optional 49-key music synthesizer keyboard, the possibility of turning the Intellivision into a multi-voice synthesizer which could be used to play or learn music.