Questions tagged [relay-computer]

Questions about computers that use electromagnetic relays as logic elements. Do not use for relays that merely switch an output (such as a cassette motor).

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34
votes
8answers
6k views

Why were relays prevalent in early 1940s computers when vacuum tubes were also available?

Many of of the computers built in the 1940s used relays for logic (see here and here): Bell Labs Model I, 1940 Bletchley Park Bombe, 1940 Zuse Z2, 1940 Zuse Z3, 1941 Bell Labs Model II, 1943 Bell ...
7
votes
4answers
659 views

Have there been any studies comparing the reliability of relay versus vacuum tube computers?

Computers of the first half of the 20th century generally used relays or vacuum tubes as their logic elements. Each of these components has there own methods of failure, but relays and tubes have a ...
9
votes
0answers
464 views

What was the specific function of the relay which captured Grace Hopper's famous "bug"?

Computer pioneer Grace Hopper often recounted the story of her team finding the first physical computer bug: While she was working on a Mark II Computer at Harvard University in 1947, her associates ...
3
votes
4answers
454 views

What is the first (say early) use of switches (mechanical or electromechanical) for sake of processing (like automatic motor control)simple data?

Switches are intended for just turning ON or OFF the power supply by either closing or opening the circuit. I often wonder how does mankind got idea to use these switch for sake of processing (simple ...
6
votes
2answers
648 views

Floating Point on Konrad Zuse's computers

From what I understand, with floating point arithmetic, shifting values up and down is important, since a floating point value essentially is an equation like 2e×m. This supposition may be supported ...
11
votes
4answers
2k views

Smallest/Simplest, modern pure relay computer with at least 4-bits data words

There are a lot of designs out there of modern home made relay computers (not just ALUs but real computers -let's call them Turing complete, although Turing complete is not enough for having an ...
17
votes
5answers
805 views

Did any computers use automatically-operated mechanical storage as electronically-read-addressable memory

From what I understand of ENIAC, it had a very large number of manually-operated rotary switches which behaved as ROM. While programming ENIAC in the early days required a plugboard, the machine was ...