albaugh@dms.UUCP (Mike Albaugh) (11/15/89)
From article <1989Nov14.020457.416@mentor.com>, by mbutts@mentor.com (Mike Butts): [I'm sure you've all seen the lead-in, or don't care. Anyway, in response to "Why would the ENIAC need something as hefty as an 807...] > > Clock drivers, I'll bet. A professor of mine worked on a 50's > Univac machine with 807 clock drivers. ZZZAP!!! I'd suspect that your professor worked on a Univac 7900, aka "Solid State 90" (aka SS80, Cambridge Airforce Computer, UEC, etc). Originally developed in the mid 50's, and with several later models. This machine used diode-core logic, which meant that the "clock driver" _was_ the principle power supply. As I recall, the clock driver provided 3KW. It used six 4cx250's (That's 250 watts of plate dissipation each), and may have used 807's as _pre_drivers. It also sported a 600 LPM printer which used octal-based Thyristors (66 of them) as hammer drivers. These machines were in use as late as the early 70's, and were very reliable. I should know, I used to own one :-) Anybody caring to hear more about diode-core logic can email me, but suffice to say that familiarity with this machine served me well when I later met dynamic NMOS logic... Mike | Mike Albaugh (albaugh@dms.UUCP || {...decwrl!pyramid!}weitek!dms!albaugh) | Atari Games Corp (Arcade Games, no relation to the makers of the ST) | 675 Sycamore Dr. Milpitas, CA 95035 voice: (408)434-1709 | The opinions expressed are my own (Boy, are they ever)