What is the difference in amount of vacuum tubes to amplifying circuits used to make computers?

Question

I'm doing a report on the History of computers, and I can't find this answer straight forward. I know computers switched from Vacuum tubes to amplifying circuits, and some computers used like 18,000 vacuum tubes- In contrast with the amplifying circuits, does each computer just need one? or a couple? I mean was it all those thousand tubes to the one circuit that made it such an improvement? Or did it just need ...less.. Like 100 circuits or something?

Answer 1

The basic mechanics of the circuits remain the same, but a vacuum tube is big, like a light bulb. So the question is this, do you have a building to put your 18,000 vacuum tubes in, or would you rather fit 100,000 on a chip you can fit in your hand?

Answer 2

Your "amplifying circuit" is too vague a term. One transistor corresponds in functionality to one vacuum tube. Convert your amplifying circuit to transistors to get your answer.

The 1946 ENIAC with its 18,000 vacuum tubes wasn't a computer, it was the last big automatic calculator.

Early vacuum tube computers through the 1950's managed with a few thousand tubes. It wasn't a big deal. Two tubes made a "flip-flop", or a single binary digit ("bit") of very fast short-term memory. Twelve tubes could make a "full adder" with two bits and a carry bit input, and one bit and a carry bit output. Twelve transistors can do the same.

A very popular tube was a "double triode" which was two independently-usable tube arrangements inside a single glass bulb, so some early computer "tube" counts could need to be nearly doubled to get the transistor equivalent.

Answer 3

Each transistor (valve, switch) requires at least one vacuum tube. An Intel Core 2 Duo processor CPU contains 291 million transistors. If a tiny vacuum tube masses 20 grams and needs one watt of power, how much does the resulting computer minimaly weigh and consume power?

Do you plan on having some RAM in there? The preceding is only the CPU.

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