Al, following up on this thread from February, in case you are still looking, I just came across my copies of: - Z-29 Uers's & Technical Guide (1983) - Z-29 ASCII character and escape code chart Despite the claim to be a "Technical" guide, the above is really more of a user manual, containing in-depth description of control codes and operating modes, but not much else (no circuit descriptions nor schematics). I'll be showing at VCF West in August, and happy to bring these along and donate them to the scan queue if you are still looking for them? cheers, --FritzM.