Well, in a somewhat random way, anyway. So I read in the manual that you can set a 707 or 727 to transmit MIDI notes for external devices.
It's not implemented very well, but considering when these were made, it at least works! For one thing, MIDI only gets sent when the machine is in track play mode. So you have to program patterns with the internal sounds, create a track and only then can you hear the sounds in an external module being triggered from the 707.
The key command is simple: in track play mode, press shift-MIDI-Inst/Guide, that's it. Press it again and it toggles back to playing the internal sounds.
One thing I noticed is the manual says that when transmitting MIDI, the internal sounds do not play. Well . . . . for fun, I set it to send MIDI and plugged the MIDI cable from the OUT to the IN and . . . it played, but not consistently. About 75%-80% of the notes in the pattern triggered doing this, but the bizarre thing is that the notes that were triggered changed every measure! Sorta like an auto-randomize! This was with a 727. I have a 707 at work that I'll try it on in a day or two and will post the results.
If you feel inclined, give it a shot and see how it goes!
Scott