▲IBM, sonic delay lines, and the history of the 80×24 display (2019)(righto.com)
65 points by rbanffy 9 hours ago | 8 comments
▲Animats 1 hour ago
The PARC crowd thought displays should have the form factor of a sheet of paper. Hence the Alto display.[1] That never caught on.

[1] https://www.righto.com/2018/01/xerox-alto-zero-day-cracking-...

▲locallost 24 minutes ago
I see people doing that today.
▲II2II 6 hours ago
Tangentially related: is there a history covering IBM's development of microcomputers? It is clear that the traditional story of the development of the IBM PC leaves out many important details. There the 5100/5110/5120, which goes back to the mid-1970's and reflects the stereotype of IBM. There is also the System/23 DataMaster, where the hardware seems to be the basis of the IBM PC. This seems to go against the traditional story that the IBM PC was some sort of renegade project. (If anything, they appear to be companion projects. The main difference being the DataMaster's focus upon IBM firmware/software.)
▲ 1 hour ago
▲kens 3 hours ago
Like I need another big project :-)

The IBM Datamaster is an interesting system, but it was doomed. It had an 8-bit Intel 8085 processor, cost $9000, and came out in July 1981. The IBM PC had a 16-bit 8088 processor, cost $1565, and came out a month later. So there was no reason to buy a Datamaster

There's a good description of Datamaster in "A Personal History of the IBM PC" by Dave Bradley (one of the PC's designers). Unfortunately, it's paywalled.[1]

[1] https://doi.ieeecomputersociety.org/10.1109/MC.2011.163

▲veltas 6 hours ago
From a linked article on shift registers:

> To avoid these astronomical prices, some computers used the cheaper alternative of shift register memory.

Might be a direction for 2026 too?

▲BirAdam 5 hours ago
Man. I love the design of old terminals, computers, and such.

I am, also, extremely glad that these form factors were abandoned. Having an old terminal, it is possibly the least ergonomic machine I have ever used.

▲thakoppno 5 hours ago
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.

▲staplung 1 hour ago
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

▲ronsor 5 hours ago
In the end, all reasons resolve to either "it's what we had at the time" or "someone thought it looked good."
▲theamk 4 hours ago
Not always, for example original CD disks had capacity of 74 minutes to accommodate Beethoven's Ninth Symphony.
▲thangalin 44 minutes ago
The linage can be traced back to Basile Bouchon's paper tape invention in 1725. The article doesn't mention the role of punched cards in The Holocaust, though, which my blog post goes into:

https://dave.autonoma.ca/blog/2019/06/06/web-of-knowledge/

▲lysace 7 hours ago
No idea if this was a factor, but 80x25 on the IBM PC allows for showing 80x24 plus that extra line of function key labels:

https://en.wikipedia.org/wiki/IBM_BASIC#/media/File%3AIBM_Ca... (IBM BASIC screenshot)

▲bluedino 6 hours ago
Imagine when edit.com came out and QBASIC used it for the editor. You lost two more lines of valuable code space!

https://en.wikipedia.org/wiki/MS-DOS_Editor#/media/File%3AMS...

▲jtarrio 6 hours ago
You know, this is funny because QBasic did not use EDIT.COM. Instead, QBasic was the editor and EDIT.COM was a simple program that called "QBASIC /EDIT" :-)
▲bluedino 2 hours ago
It was basically the same thing. That's my point.
▲lysace 2 hours ago
I recently went back to my 1993 Turbo Pascal code (mostly 2D VGA and Sound Blaster game engine experiments) on period correct hardware.

I was surprised by how claustrophobic it felt to only see 21 lines of code in e.g. Turbo Pascal 7.0. Still didn’t like the squashed 80x43 mode.

https://winworldpc.com/screenshot/c38a28c3-84c3-ba28-1011-c3...

Then I remembered how larger displays and xterm felt like such a liberation a few years later.

▲hanfoo 6 hours ago
Deeply fascinated by these historical threads. It is precisely the various design choices made throughout history that have shaped the computer systems we use today.