Collapse OS
I don't think just developing a Z80 operating system is enough. The whole ecosystem needs to be preserved.In agriculture, we have the doomsday seed vault [0] just for this purpose. If we anticipate collapse of the current economic system or society, I think we should build a doomsday computer vault, that keeps everything we need to rebuild the computing industry in a underground bunker. It keeps everything we need in a controlled environment, such as 8080, Z80, m68k, motherboards, logic chips, I/O controllers, ROM/RAM, generic electronic parts, soldering irons, oscilloscopes, logic analyzers, schematics, documentation, textbooks, software. We also keep some complete, standalone computer systems such as desktops and laptops, and all the parts that need to service them. We also need to preserve the old semiconductor production lines around the world, although probably not in the same bunker. Even if we fail to build better systems, 8080s are already useful enough!Meanwhile in peace time, we need to form a team of experts that makes a roadmap to rebootstrap the computing technology for the future using parts from the bunker, with a step-by-step plan, that can be easily followed and executed.[0] https://en.wikipedia.org/wiki/Svalbard_Global_Seed_Vault