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From: Dan Espen <dan1espen@gmail.com>
Newsgroups: comp.misc
Subject: Re: IBM, sonic delay lines, and the history of the 80x24 display
Date: Mon, 29 Apr 2024 21:42:49 -0400
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Ben Collver <bencollver@tilde.pink> writes:

> Some theories about the 80x24 and 80x25 sizes
> =============================================
> Arguments about terminal sizes go back decades, [5] but the article
> 80x25 presented a detailed and interesting theory. To summarize, it
> argued that the 80x25 display was used because it was compatible with
> IBM's 80-column punch cards, [1] fits nicely on a TV screen with a
> 4:3 aspect ratio, and just fit into 2K of RAM. This led to the 80x25
> size on terminals such as the DEC VT100 terminal (1978). The VT100's
> massive popularity led to it becoming a standard, leading to the
> ubiquity of 80x25 terminals. At least that's the theory.


It's always be obvious to me that the PC was 80x25 so that it could
accurately emulate a 3270 24 line display.

A 3270 HAS a 25th line where is displays some additional information
like whether the keyboard is locked.  There were 24 lines of data and a
25th line for status information.

-- 
Dan Espen