Hi,
this reminds me of something.
I believe at least the Polysix and the MonoPoly use the same assigner.
Polysix8049C217
Monopoly8049C217
Same for the old revision of the Poly-61.
The Poly-61 (being a 6-voice synth) could lend useful insights here.
The MonoPoly has a "Tune Point Switch" that - as far as I can see -
connects pin 34 to pin 19 for the initial tuning procedure.
> The voltage at TP2, called Oct/V CV, which seems to be the input
> to the antilog ckt, is constantly switching between 8 values. Six of them
> are the same when you go into unison mode, but there are still two other
> ones being muxed in. I guess for the factory calibration they must
>have had
> a way to pause the muxing and put out specific DAC values for setting the
> trimmers using a DMM. Seems like that code would be in the keyboard
> MCU, unless they had a factory test MCU that they used.