Lets say your region becomes isolated for some reason: How'd you build computers in that situation?

If I understand correctly there's plenty of factories around the world capable of manufacturing 1980s-era microchips. And if your region doesn't have one, projectors can with some effort be repurposed to write microscopic circuits onto photosensitive silicon.

You'd still need to find somewhere to get the materials... And purify them... I don't feel qualified to comment on that!

1/3?

Perhaps the main thing we do with our computers is to store data on them, so what's a relatively low-tech way to store non-trivial amounts of data?

Fragile wires is an attractive way to create write-once (PROM) microchips. Though in some way or other we'd probably use magnetism again to store data. A grid of wires, with the columns using thicker wires & being wrapped around the rows is an attractive approach that was quickly overshadowed in our history.

2/3?

For human-interaction...

Modern cost-reduced keyboards require little more than molds & silkscreens. Though we can't have modern "optical" mice with 1980s-era compute, so it seems reasonable to go back to ball-mice.

For output... I think we should be able to manage speakers & (even if incandescent) lights. Black & white CRT-monitors may well become a value-add. I'm assuming that if we can manufacture microchips we can draw a vacuum.

Any further thoughts?

3/3 Fin!

@alcinnz

Oh boy, oh boy!

I happened to watch a documentary on the difficulties of purifying silicon.

It's not an easy feat. At all!

It took the industry years of experimentation and trial-and-error to reach the capability of creating silicon crystals pure enough to build nicrochips.

Creating the chips might seem easy, but there are like three factories in the entire world that provide all the industry with semiconductor grade silicon.

@yuki2501 O.K., maybe we'd have to go back to raw transistors & non-integrated circuits... As @vidak said, gallium-arsenide transistors can be handmade.

Certainly it'd be tempting to use whatever wafers we have on hand to massproduce the more tedious components, like decoders...

@alcinnz Digital data on wax cylinder/platter feels like something that would be fun to play with.

@LovesTha @alcinnz in my musings on mechanical digital computers long ago I imagined read-only storage consisting of pressed vinyl records with pits and lands much like an optical disc

@alcinnz plenty of fabs able for 2000s era chips

@ColmDonoghue Hmmmmm, for my tastes that sounds like plenty capable!

@alilly @alcinnz I'm guessing that some form of more complex AM or FM encoding of the data is probably going to work well, let alone something actually good that the boffins could think up.

@LovesTha @alcinnz yeah I imagine reality would be more complex; even analog audio records are two-dimensional (they use the depth as well as lateral wobble to store the two stereo channels, and I think it's a bit more complex than just one is left and the other is right) and we have coding schemes like QAM and TCM available to us

@alilly @alcinnz Yamaha implies it isn't much more complex:

@LovesTha @alilly Here's @TechConnectify 's video on the subject: https://inv.nadeko.net/watch?v=3DdUvoc7tJ4

@alcinnz @vidak Pump it up a little, and we might end up having to make Vacuum tubes.

Which are totally valid, BTW, but still require 20th century technology.

@alcinnz I bet we could do something with all the microplastics in our body! 3D print the cases for the chips or something.