via this auction
"This unit, serial number 1010-0078, is the final production version of the Prophet-10 designed around two Prophet-5 Rev 3 voice boards. It has enhanced microprocessor control circuitry and software to provide 10 polyphonic voices (2 VCOs each) in four keyboard modes with responsiveness comparable to the Prophet-5. These modes allow the choice of separate polyphonic control of two 5-voice synths, combined control of a “stacked” pair of 5-voice synths, alternating notes between two 5-voice synths, or control of a single 10-voice synth. Additional features not found on the Prophet-5 include programmable 3-band equalization, two control voltage pedal inputs with assignable routing, three foot switch inputs and a 10,200 note polyphonic sequencer. It is equipped with Sequential’s MIDI interface kit and the latest firmware, Rev 6.1. Recently the unit was thoroughly tested, repaired and burned-in by Wine Country Sequential in preparation for sale.
As you can see in the photos, the end result resembles an Oberheim Xpander, but with the familiar Prophet-10 control panel and no keyboards. This reduces the depth of the instrument to 13-1/2 inches and weight to 43 pounds – a much more practical size for lifting, transporting and integrating into an electronic music studio or performance system. For example, this slim rendition of the Prophet-10 rests comfortably on an Apex column stand.
NOTE: The circuit boards contained in the synthesizer unit are unaffected by the “Riley Mod” and have not been modified in any way except for installation of the factory-supplied MIDI upgrade kit..."