via this auction
SN 1627
Description via wikipedia: "The Moog Source is a microphonic Z80 microprocessor-controlled analog synthesizer. Manufactured by Moog Music from 1981 to 1985. The Source was Moog's first synthesizer to offer patch memory storage. The design was also the first (and only) Moog synthesizer to feature a flat-panel membrane keyboard to replace the standard buttons, knobs and sliders, along with multitude panel graphics that were very different from anything Moog offered at the time.