I was thinking the easy way to add an oscillator to my Micro is simply to use what I have and tap into the control system of the Prodigy via the Open-System ports on my Micro.
I’d run the audio from the Prodigy into the Micro’s audio in.
Suggestions?
That’s it, you got it in a nutshell. Note that the Open System you are referring to is an old expression, not used all that much. Moog used so many expressions over the year to describe things that were quite unknown about synths in early days. Today, we will talk mostly in CV terms (control voltages). You transmit pitch CV from one synth to the other with a patch cable, and the Gate CV with another. Those early Moogs used S-trigger instead of V-trigger on modern ones. Not much of a concern to you since you have two vintages.
There is a problem though. Cinch Jones connectors are somewhat harder to buy over the counter. Many early Moogs are modded to use the more standard quarter inch jacks that are used nowadays. Even on a jack, a V-trig remains a V-trig, but you should learn the difference between a V-trig and S-trig, should you want to expand with synths that use V-trig.
You may want to feed audio from the satellite synth into the one you play (with audio in), and control filters and stuff from one, or you can also send the output of each to a mixer to obtain two different sounds, while playing from a single keyboard. There’s no right way to do it, it’s up to you.
The Micro-Moog user manual can be a bit of a hard reading when it starts to talk about patch cables, and connections to other ‘open system’ synths. I suggest you read some other vintage Moog user manuals as well, and get a good grasp of things, before bringing a soldering iron into the guts of your machines, as your other post suggests. (mods)
Thanks for the description - I thought Open-System was something new (I’m currently looking at a system called Open-Scope - it’s in my sig, so I was getting confused). Never heard of it before.
I don’t think you can use “new” and “Micromoog” in the same sentence. Open System was a proprietary pre-MIDI specification that would allow two Moog synths to communicate with one another. Not sure how it worked; I never messed with it…probably sent CV’s back and forth, or something. 
I had to look it up on the web too. I thought at first he was referring to some kind of company offering some mods. In other words : Open System = modular.
The only reason I know about it is because I saw a Micromoog at Music-Go-Round,and it had that Open System jack labeling. Apparently, it was for those who wanted more out of their Micromoog. You could daisy chain multiple Micros together to get a hugely expensive 12 oscillator monosynth, or a more reasonable 2 or 3 oscillator synth. That’s how the guy at Music-Go-Round put it, anyway. Basically, all the CV ins and outs are Open System.