I've stumbled on this operating system that is meant to run on cheap inexpensive chips (Z80). Not so sure if it will be real-world scenario to use that OS even on the event of civilization collapse. However, I leave here the link: https://collapseos.org/
Winter is coming and Collapse OS aims to soften the blow. It is a z80 kernel and a collection of programs, tools and documentation that allows you to assemble an OS that can:
- Run on minimal and improvised machines.
- Interface through improvised means (serial, keyboard, display).
- Edit text files.
- Compile assembler source files for a wide range of MCUs and CPUs.
- Read and write from a wide range of storage devices.
- Replicate itself.
Additionally, the goal of this project is to be as self-contained as possible. With a copy of this project, a capable and creative person should be able to manage to build and install Collapse OS without external resources (i.e. internet) on a machine of her design, built from scavenged parts with low-tech tools.