Look at the referenced IBM docs: They included the actual schematics of the adapters. I don't know if they are 100% complete, but even so, that level of technical detail is almost unimaginable now.
(I hope the link works, otherwise, see e.g. page 19=28).
When I joined my church choir in 2006, we had an unnecessarily elaborate sound system, including "rock star" solo mics for every individual chorister and a 24-channel mixer that nobody knew how to use.
By 2010 we'd updated it to a correctly sized system with a more modest mixer that nobody knew how to use, either.
Therefore, I took it upon myself to search by model number, print out a pair of copies of the comprehensive user manual, and then I tucked one of them snugly into the rack mount for reference by any current and future directors.
The fact that the public could get these at all. I have another one of these with the BIOS source code. I don't think e.g. HP would publish a schematic or BIOS source for one of their laptops today(I'd love it if you prove me wrong, of course) . Otoh, I have an old 1960's tube radio, and the full circuit is attached to the backplate, in the expectation that you might want to replace a resistor some day.
Tandy's machines came with similarly detailed information and schematics as a part of the purchase. Same for many of the rinky-dink 8-bit home computers like the Commodore 64. Today's machines, if their parts have tech specs at all, they're at the bottom of a locked filing cabinet in a disused lavatory with a sign on the door saying "Beware of the leopard".
To be fair, to fully document a modern computer would require more paper than what a managed forest that covers an average rocky planet would be able to provide in a decade.
I was gonna say, "or tube", but then again, I think the tubes were standard models so you'd just bring your tubes in to the department store, test them in the tube tester⁰ and get your replacement.
author = {Ronald G. Minnich and James Hendricks and Dale Webster},
title = {The Linux {BIOS}},
coreboot:
Werner Zeh, David Hendricks, and Matt DeVillier.
Felix Held
Jay Talbott
Patrick Georgi
Stefan Reinauer
Ron Minnich
Martin Roth
Tim Crawford
Felix Singer
Marshall Dawson
Christian Walter
Julius Werner
Michał Żygowsk
Piotr Krol
Arthur Heymans
Angel Pons
Eric Peers
It's typical for a datasheet, but when was the last time you were able to get a proper datasheet for the electronic components and devices you use every day?
Square pixel 360×240 was sane, but 360×480 always felt dirty.
IIRC, Mode X video mode set routines boiled down to an exhaustive table of VGA register control values. (See SDL or older FreeBSD for examples.) Then, the fun was pixel addressing, bitblting, and page flipping.
Then "succeeded" by "Area 5150" past year: https://news.ycombinator.com/item?id=32394195