Rebuilding Civilization from Scratch?

To have computers that are anything close to what you'd recognize as a computer today, you'd need to have an electronics industry that's capable of manufacturing semiconductors, disk drives, CRTs, etc. These rely on many different raw materials which take complex industrial processes to produce. You will probably have to rebuild most of modern civilization (power plants, mines, factories, vehicles, roads, etc.) before you can even think of building computers.

Yes, you could build computers out of relays or vacuum tubes, but their computational power would be very limited. You're not going to be able to run Unix on hardware like that. That technology was very slow and had to be repaired frequently (if you have thousands of vacuum tubes, one would burn out every few hours).

I'm interested in what anyone else finds. These are projects i'm aware of that are periphery to your request and valuable in their own right.

https://www.opensourceecology.org/gvcs/ http://digitarworld.uw.hu/ttlcpu.html https://monster6502.com/

This is an interesting question. As another poster said, to do this we would probably have to rebuild most of modern civilization. Leaving instructions to do that seem almost impossible.

I honestly think though that leaving behind a detailed record of what is possible and how things used to be would be very valuable in this situation though. Just letting people know computers did exist and did require electricity and what electricity was and that we used to burn something called coal to make it would for sure speed up a future civilizations research dramatically.