Two replies to things Larry said:
ARM or one of the smaller RISC-V flavor-sets (RISC-V is super-modular)
would be a perfectly reasonable architecture to learn these days. After
the PDP-11 but before ARM I'd'a suggested 68000. Definitely NOT x86 and
its betentacled descendants. Even so, you'd still want to treat it (if
you're learning "how do computers work?") as if it were not superscalar,
even though it obviously is. Which I guess is pushing me into "please let
me just pretend it's a PDP-11 and keep all the scary pipelining and
speculative execution and all the things that are hard to reason about
below the layer where I need to care" territory.
And yeah, if you need me to sweep the floors, I'll sweep the floors, but if
I'm needed to sweep the floors often, there's a management problem here, in
that you can hire people who are much better at sweeping floors than I am
for much less money than you hired me to do software engineering for.
Adam