Schematics / Tau 1005 VCO
Tau 1005 VCO by Tau Systems ,brief comment from Aaron D. Lanterman on this circuit http://users.ece.gatech.edu/~lanterma/ems11/projectideas_sp11.html :
Looking at the schematic, you'll see it's a triangle core like the Buchla 259 core we discussed in class, except a CA3080 is used instead of the "roll your own" 4-transistor OTA Buchla uses. The HA2500 op ap is acting as the comparator, and the FET and BJT at the output of the 3080 are acting as a buffer. I think the weird configuration of Q5 and Q6 is acting as a voltage clamp. It appears to have been intended to be some sort of plug-in module for a bigger circuit.