Vintage Synth Repair

Hi everyone,

I have a question about the early Moog Modular 901a/b Oscillator Controller/Driver.

The cicuit diagram can be found here at the Moog Archives here:
http://www.moogarchives.com/  (click 'modules' on the left)

Looking at the cct diagram connector pin-out, there are 'A' 'B' and CONTROL NODE pins.

Now, the 901b Oscillator connector pin-out has an 'A' 'B' and 'C' - would the 'C' interface with the CONTROL NODE pin on the Controller/Driver cct?

Also, the Controller/Driver connector shows the 'Width of pulse waveform' circuit between pins 6 and 13 - but that seems to be it - pins 6 and 13 do not appear anywhere in the circuit... where does this pulse width circuit interface to..?

I hope someone can shed some light on these mysteries.

Thanks in advance,
Tom