The biggest problem is displays. Building a simple CPU is not too hard if you have the components and schematics, but how do you build a CRT or LCD without a hu

The biggest problem is displays. Building a simple CPU is not too hard if you have the components and schematics, but how do you build a CRT or LCD without a huge industrial manufacturing backbone? We would be back to LEDs, maybe some handmade nixies, and entering code in hex or octal. Computing would just be OVER in a few years without modern supply chains and infrastructure. Also, what CAUSES the collapse? Solar flares could wipe out a large portion of tech on earth very quickly. World nuclear war as well. Those could set us back many decades or centuries in terms of technology, and that vulnerability will only get worse the further we advance. If you're expecting such an event, a safebox full of microcontrollers and equipment with a faraday cage might be a good investment.