The shape of the pulse & square waves in particular are very interesting.
I have a few 1023s in my system and each has 2 oscillators. So I did compare
one with the other and found lots of variation.
This oscillator features the same waveforms as the 1004 module with a switch for high and low frequency ranges.
The VCO was tuned to A (440Hz).
Pulse from 1023# 1
The second Pulse wave from 1023# 2 looked like this:
The plugin is from jaggedplanet.com
My favorite oscilloscope vst.
Ramp/Sawtooth from 1023# 1
The second saw from 1023# 2 looks thus:
And the Square:
Square of VCO #1
The square of 1023# 2
There doesn't appear to be much variation among sine & triangle waves between the various oscillators.
These VCOs are nearly 50 years old so it doesn't surprise me to see variations. Those old caps and resistors all add up to give these beautiful differences that add to the richness of the 2500's sound.