Vacuum Tube Calculator Schematic

If the Euroweenies had their way it would be a single .45 liter cylinder.

You've gotten a number of good tips so far.

The thing you want doesn't seem to exist as such, so what do you want at this point? I have some olde-tyme schematics of tube logic circuits, if that's any help.

Oh, and you can make pretty much any logic circuit out of neon bulbs, like the NE-2. Flip-flops, decade counters, etc. NE-2's are cheap, need no heater, and it might be fun to watch the calculator run (verrry slowwwly).

Do any of those sound useful to you?

James Arthur

THE STANDARD ADVICE: There is a way to influence what gets discussed in a newsgroup that works well, and another way that has never worked no matter how many people have tried it. What works: Post articles on the topic you wish to see discussed and participate in the resulting discussion. Use killfiles and filters so that you don't see the articles containing discussions that you do not like. If you don't know how to use a killfile, use good old fashioned discipline and don't read posts by people who post articles that you wish there were fewer of. Never, ever respond to any articles that you dislike. What doesn't work: Respond to articles that you don't like. Complain about articles that you you don't like. Complain about posters who post material that you you don't like. Complain about how terrible everyone else is for not posting things that you want them to post. Talk about how to respond to articles that you you don't like. Ignore the good material that you want more of while making the bad material that you want less of the center of attention, the main topic of discussion, and a personal crusade. -Author: Guy Macon

if you have a chance , visit the Computer History museum, where there are many wonderful things to see, also, a great library.

BTW, the Babbage difference engine is very interesting

good luck,

Jure Z.

I have a 5 pound bag of matched NE2s, would be glad to send some to you via your science teacher.

Steve

Here are some gates and adders and memory drivers and stuff:

Have Fun! ;-) Rich

Phaugh! You can build a 2-bit full adder with a handful of gates. Admittedly, it might be the size of a coffee table, but that's just about right for a science fair. Start with an "and" gate, an "or" gate, an inverter, and look up logic diagrams for CPU stuff - mostly adders. ;-)

You'd use pushbuttons or toggle switches for the inputs, and NE-2s for the outputs. ;-)

Cheers! Rich

You might have to use two books in concert - one about logic stuff, and another on how to put tubes into the circuits. :-)

BTW, this is for next year's science fair, right? ;-P

Have Fun! Rich

You could do it with a couple of dozen, if you have serial memory and know how to do it serially. You only have to do one bit at a time if you do it serially. It might take a moment or three, but the job will eventually get done. ;-)

Serial memory: think of a 64-track tape in a loop, with pairs of read/ erase/write heads... Kind of a magnetic Turing machine on steroids. ;-)

Cheers! Rich

Just put tubes in place of transistors, and adjust the impedances and biasing appropriately. ;-)

Have Fun! Rich

The purpose of a science fair is to showcase the student's work. So if I hand you all this stuff on a silver platter, then that entitles me to any and all prizes or other accolades, including my transportation to and from the awards ceremony and any necessary lodging, transportation, and $120.00/day per diem, so you can show everyone who really did it for you, right?

Good Luck. Rich

So are useless googlies asking for people to do their homework for them, for free, no less!

Don't start vast projects with a half-vast ideas.

Good Luck! Rich

snipped-for-privacy@frank-buss.dehttp://www.frank-buss.de,http://www.it4-systems.de

Why this Jones for schematics? Are you completely ignorant of electronic principles?

No, they don't. Design of combined sequential and combinatorial circuits is all that is needed. I could maybe do it in less than 100 tubes / transistors. Part of the problem is partitioning the complexity between the sequential part and the combinatorial part.

Gee, are you talking about 64 bit words? In the general case one tube per flipflop or gate. 1/2 tube for an inverter.

A direct state machine yes; a microcoded one no.

Too sparky. (The low spark of high-heeled boys)

Finally had to look it up. Up the universe, the US Navy destroyer i was on the mid 1970's had an internal telephone system (200 lines 20 connections i think) based on descendants of the Strowger switch. Yes i am certain, i saw it in operation. Now that is technical longevity.

Thanks guys, but I don't really have time to respond right now. I'm working on the science fair!

I'll respond to all your stuff later, just so you know I'm still here.