YouTube via 1dayhkr | June 27, 2010 | 9:53
"For Sale -
This for demonstration only, for the purpose of showing that this synthesizer is in great working condition. Shows the following: laying down of tracs, basic use of panel components and sounds."
via this auction
"1984 - 1985 Vintage Sequential Circuits SIX TRAK synthesizer Model: Prophet 610 in the original box... This 4 octave keyboard comes equipped with midi in and out and when linked to a drum tack machine, combines the multi-timbred ensemble with a programmable rhythm section. Each sequencer (A or B holding six separate traks) allows for an 800 note memory allocation per sequence, and this memory storage can be increased to 4000 notes when combined with a model 64 sequencer. Of course, with midi, the playing field is wide open to many possibilities that go beyond the two I have mentioned. The back panel also includes audio out which can also be used for a head phone jack or a speaker output, and a footswitch controller jack is also present. The foot switch is not provided, but is an inexpensive purchase that can be obtained through any music store. This fun machine also includes a pitch and modulation wheel, polyphonic and unison mode functionality, programmable track speed and volume, track erase, memory – full warning, legato function, voice stacking, a flexible arpeggiator and 100 ready –to-play factory programs." 
