One theory I saw argued the punch card size was the reason for 80x24. But why were punch cards that size? They were designed off of the cards used for the census. Why were the census cards that size? Because they were modeled after the dollar bill size.

I do love thought experiments like this but do believe they’re insatiably unresolvable.

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staplung 2 hours ago | parent | next [-]

And the reason they were modeled after the dollar bill size is because there were already many types of systems for storing and organizing them. That came in handy for the census.

The old BBC Connections series has a segment with James Burke using the old census tabulators.

https://www.youtube.com/watch?v=z6yL0_sDnX0&t=2640s

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ronsor 7 hours ago | parent | prev [-]

In the end, all reasons resolve to either "it's what we had at the time" or "someone thought it looked good."

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theamk 5 hours ago | parent [-]

Not always, for example original CD disks had capacity of 74 minutes to accommodate Beethoven's Ninth Symphony.

	▲	rasz 42 minutes ago \| parent [-]
		That one also turned out a myth :) CD size was determined by Cassette tape dimensions (diagonal, human can still hold one in one hand) and that combined with conservative pits/lands/track pitch choice drove the play time. thus CD runtime was derived from something "what we had at the time".