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Questions tagged [early-computer]

Early computers and their design, from before the standards set by the IBM S/360 (of 1964) became canon.

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17 votes
1 answer
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How were Zuse Z22 Instructions Encoded?

The title says it all: How to En-/Decode Z22/Z23 Instructions? (History and Linkage: The question was raised by Wilson in a comment on my answer to his question "Why are PDP-7-style microprogrammed ...
Raffzahn's user avatar
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52 votes
4 answers
6k views

Why did the IBM 650 use bi-quinary?

The IBM 650, announced in 1953, was the world's first mass-produced computer. It represented numbers in decimal, which is understandable, both because it needed to work with exact money amounts, and ...
rwallace's user avatar
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15 votes
4 answers
6k views

How could early computers perform data operations before John von Neumann proposed the concept of ALU?

According to Wikipedia, John von Neumann proposed the Arithmetic and Logic Unit concept in 1945. Mathematician John von Neumann proposed the ALU concept in 1945 in a report on the foundations for a ...
Noob_Guy's user avatar
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29 votes
3 answers
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Why does an instruction include the address of the next instruction on the IBM 650?

The IBM 650 seems to be a load-store machine. One advantage of a load-store machine is that the instruction can be shorter because there's less pressure to pack more information into it. But the IBM ...
Omar and Lorraine's user avatar
12 votes
3 answers
1k views

What is the instruction set of the Z4?

I am able to find a few instructions, such as: Fin (presumably "Fine", as in the end of a musical score, ends a program), Fin', (a conditional Fin), St (possibly "Start" -- the need for this is ...
Omar and Lorraine's user avatar
2 votes
2 answers
498 views

What early computers were only able to print numbers?

According to this paper (translation), one of the early soviet machines, M-1, was only able to print decimal, and not alphabetical numbers. Which other early electronic stored program computers (i.e. ...
lvd's user avatar
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