[dcminter]

I'm 99% sure the original kernel and thus the boot&root disk Linux (the original "distribution" I guess) only ran on the 386 & up as it required & used the memory management capabilities.

There were some forks that could run without the mmu (micro-Linux I think?) but as I recall it they came quite a bit later.

Edit: Ah, close, this: https://en.m.wikipedia.org/wiki/%CE%9CClinux

[ghaerr]

We dropped all support for 286 or 386+ protected mode/paging etc, as well as produce only 8088/8086 instructions so it'll run on any x86 (including the PCjr with its peculiarities, remember that?) running in real mode only without MMU. Of course, that means any program can write anywhere, so more care is taken towards program correctness, which is kind of fun.