Been hunting around the web for the 3340 with thru-zero FM (TZFM) and finally landed on this project.
Making an inexperienced guess that this is based off of J Haible’s VCO, due to the comparator logic gate setup for TZFM. It’s been talked about how the 3340 has “glitchy” thru zero, and I don’t know what that would sound like, but the soundcloud link sounds pretty good! The soundcloud links are broken in the post but I just Googled openCEM3340 and got it.
The rest is based around the Digisound 80 VCO.
it’s a pretty involved project, and it’s specified for the CEM and not the Alfa AS3340 (which I have) but I wanna give it a shot soon.