Casio is a Japanese consumer electronics company that was making synthesizers until 1992. All of the synthesizers made by Casio were digital. The products had menus for programming interfaces at the synthesizers. The Casio CZ series used what Casio called 'Phase Distortion Synthesis'. The Casio VZ series used 'Interactive Phase Distortion' and the Casio FZ line consisted of 16 bit sampling units. The CZ line was one of the first commercially available MIDI keyboards commercially available. Casios MIDI keyboards and synthesizers are listed here.