This instrument, eventually released by Fender as the Rhodes Chroma, was one of the early microprocessor-based analog synthesizers. It was the first commercial synth with a touch-sensitive keyboard, using 64 weighted wooden keys; some units also included a polyphonic pressure sensor under the keys. The synthesizer had 16 channels normally used in pairs for 8-note polyphony. It was controlled via a panel consisting of multi-purpose touch switches for selecting sounds or parameters of sound with a single slider for adjusting parameters. This approach was later copied by many more successful synths, such as the Yamaha DX-7. The microprocessor was a 68B09, and it had a computer interface consisting of a 25-pin D-sub connector. (This was before MIDI was invented.) An Apple IIe interface card with sequencing software was released later on. Eventually, a third party came out with a Chroma to MIDI converter box. Fender also released a keyboardless version called the Chroma Expander, which could be slaved to the Chroma via its computer interface.

The Chroma was rather expensive, and Fender wasn't as good at selling high-tech keyboards as it was guitars and amps, so it never sold that well. However, it developed a sort of cult following. See http://www.rhodeschroma.com/?id=chromacult.