"bfranchuk at jetnet.ab.ca" <bfranchuk at jetnet.ab.ca> wrote: Nothing prevents the PDP8 from sending data even if your serial device is turned off. :-) Hmm. The paper tape of the ASR33... Was there some signal run in parallel for the reader run? What did you hook the other end to then? The KL8-JA (and KL8-E) don't have any more signals that I can remember offhand. There was an option for the KL8-JA (called KL8-M I think) which implemented partial modem signaling, if you needed that. Never seen one in real life, and I can't remember if I ever read any documentation of it. But you'd most likely need software to actually implement the signaling anyway. It won't be a hardware-only solution... Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol