Software archaeology: I wrote most of this program ~1970 in S/360 assembly language, using w24-bit addressing (&I used the high 8-bits for flags), ~45 years later, it was still getting occasional use. https://en.wikipedia.org/wiki/ASSIST_(computing)

UNIX really got going on 16-bit PDP-11/20s with <64KB memory.

Software far outlasts hardware.