Weren't the original TRANSIT computer (AN/UYK-1) proofed out in vacuum tubes before they were able to build it with transistors?
-- Kenton A. Hoover [email protected] +1.415.830.5843 On Sunday 23 June 2013 at 14:50, Paul Berger wrote: > Hi: > > The SAGE computers, which I had the pleasure of seeing the last two > operating, had an all vacuum tube array of core that consisted of 33 > planes of 64 x64 cores for about 16K worth of memory. These where all > vacuum tube computers. IBM offered a 4K all vacuum tube core storage > unit for the 701 and 702, the same unit was built into the 704 and the > 705 had a larger core storage with 35 planes of 50 x 80 cores. The > Remington Rand Corp. and the RAND Corp. also shipped computers that used > core for main storage in the mid 50s which likely used vacuum tube > drivers. At that time there where apparently no transistors available > that could supply the drive current required for core memory. > > On 6/23/13 5:29 PM, Bob Camp wrote: > > Hi > > > > I've both used and worked on core memory machines. They ones I have seen > > all used solid state devices in the core memory sections of the machine. > > I've never heard of a pure tube machine with more than "register sized" > > core. > > > > Bob > > > > On Jun 23, 2013, at 1:47 PM, Chris Albertson <[email protected] > > (mailto:[email protected])> wrote: > > > > > Magnetic cores were not invented until the 1950's and realy cam into use > > > as > > > tubes were beibg replaced by SS. But there isnot reason yu can't build a > > > tube computer with core memory. I have actually seen and used a computer > > > that had one megabyte of core memory. The stuff was still in use in the > > > late 1970s 1MB was a lot of RAM in 1975. > > > > > > You can have very good reliability with tube circuits. It was just that > > > few people wanted to pay for it. Down time was cheaper. It is not hard to > > > add redundancy to a circuit but it does have a huge cost multiplier > > > effect. > > > 4x or 5x the price. One simple way is to use 3 or 4 tubes with their > > > output tied to a resistive adder. If one tube fails the result (because it > > > is binary) is still the same. With computers no one would pay for fault > > > tolerant design until it was reasonably affordable. Even today we mainly > > > just put up with failure except for airplane controllers, huge web sites > > > like Amazon and the like. > > > > > > > > > On Sun, Jun 23, 2013 at 9:53 AM, Brian Alsop <[email protected] > > > (mailto:[email protected])> wrote: > > > > > > > On 6/23/2013 14:40, Bob Camp wrote: > > > > > > > > > Hi > > > > > > > > > > AC137 doesn't ring any bells. True tube core (no solid state at all) > > > > > isn't something that was dimensioned in K words. A couple hundred > > > > > words was > > > > > pretty big stuff. "Quite a bit" of core done that way is a lot of > > > > > tubes. As > > > > > the number of tubes goes up, the time to failure comes down….. hours … > > > > > minutes … who knows. > > > > > > > > > > Bob > > > > Yeah, it gets to be like the cross country aircraft races in the 20's. > > > > The > > > > mechanic had to fly with the pilot. (The MTBF of many of the engines > > > > used > > > > was measured in hours.) If necessary he had to climb out on the cowling > > > > while in flight to change plugs and fix whatever possible without > > > > landing. > > > > What would OSHA say about that? > > > > > > > > Needless to say future generations will probably find lots of aircraft > > > > spark plug artifacts in their digs. > > > > > > > > Brian/K3KO > > > > > > > > > > > > > > > > ----- > > > > No virus found in this message. > > > > Checked by AVG - www.avg.com (http://www.avg.com) > > > > Version: 2012.0.2242 / Virus Database: 3199/5932 - Release Date: > > > > 06/22/13 > > > > > > > > > > > > ______________________________**_________________ > > > > time-nuts mailing list -- [email protected] (mailto:[email protected]) > > > > To unsubscribe, go to https://www.febo.com/cgi-bin/** > > > > mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > > > > and follow the instructions there. > > > > > > > > > > > > > > > -- > > > > > > Chris Albertson > > > Redondo Beach, California > > > _______________________________________________ > > > time-nuts mailing list -- [email protected] (mailto:[email protected]) > > > To unsubscribe, go to > > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > and follow the instructions there. > > > > > > _______________________________________________ > > time-nuts mailing list -- [email protected] (mailto:[email protected]) > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > _______________________________________________ > time-nuts mailing list -- [email protected] (mailto:[email protected]) > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
