scopes, There was also a 4023 "non-graphic" terminal, significantly prior to the 4025. It used SSI and MSI TTL logic, early IC-RAM (don't know if it was dynamic or static), and a MOS character generator. The CRT used a rather slow-responding white phosphor that made it a little difficult to read when it scrolled. When I was a Systems Operator (as they were called in those days) of Tektronix' Scientific Computer Center Control Data Cyber 73, a Tek 4023 terminal was situated next to the big dual vector CRT console. This terminal was logged into KRONOS (the timesharing operating system that ran on Tek's Cyber 73) as an administrative user that would pop up messages with user requests to do things like mount tapes, and other messages from users, and the operator could respond through this terminal. The 4025 came significantly later, and I believe, was microprocessor controlled. The coolest Tektronix terminal, if you ask me, was the original Tek 4002. It did use Tek's famous DVST (Direct View Storage Tube) display that was really made famous by the 4010. The 4002 (and slightly updated) 4002A were big terminals, with a "drawer" packed full of electronics. The coolest part was the "^G" (bell), which was a really nice tone generator. I can't remember if it was a hack, or production, but there was an escape sequence that you could send to change the frequency of the tone emitted with control-G was received. With this, people had written some programs on some a DEC PDP-8 (it may have been a PDP 8/I IIRC) that could play music on the terminal, while drawing some graphics on the screen at the same time. There also was a 'write through' mode, again, not sure if it was a hack, or part of the production terminals, that would (within the limitations of the RS-232 port) could do simple dynamic (non-stored) vector graphics. There was a little game, again hosted on the PDP-8 machine, that would play a game where two tanks opposed each other with interposing landcape (hills or elevation changes) and players would take turns aiming their gun, and shooting a shell at the opposing tank. I also recall that for high-speed use, there was a direct DMA parallel interface that would hook to a PDP-11 (Unibus) that allowed some actually fairly high-performance vector graphics on the 4002. Would love to find a 4002 or 4002A around somewhere. Would also love to find one of those 4023's -- it really was a great old terminal. For a time, I had one of them at home, hooked up to an acoustic coupler and I could dial into the Cyber at 1200 baud, and do work from home. Those were good old days! Rick Bensene The Old Calculator Web Museum http://oldcalculatormuseum.com