I'll add to the other suggestions with any of the Acorn Risc OS line[1]. They're the original Arm based computers (not counting the development processor for t

I'll add to the other suggestions with any of the Acorn Risc OS line[1]. They're the original Arm based computers (not counting the development processor for the BBC Micro) and some of the earliest system on a chip computers. Might be fun if you fancy playing with Arm assembly language. https://en.wikipedia.org/wiki/RISC_OS https://en.wikipedia.org/wiki/RISC_OS https://en.wikipedia.org/wiki/Acorn_Archimedes#Later_A-series_models https://en.wikipedia.org/wiki/Acorn_Archimedes#Later_A-serie... https://en.wikipedia.org/wiki/Risc_PC https://en.wikipedia.org/wiki/Risc_PC [1] I say Risc OS but they actually also supported a Unix like called Risc ix.