I've been looking for one for ages, but it never popped while I was on the hunt!
Would be very interested to know more about it, but first where it is located...
-Roland JX3P+PG200, D50+PG1000, Juno 6+106, MKS50/70, JP8080, U220, MVS1, MDC1, MSE1, TR-707
-Korg M1R, MicroKorg, Micro X, Kaossilator/Pro, Monotron X3
-Yamaha DX7, TX816, TX81Z
-Future Retro 777, DSI Mopho, EMU Proteus FX