The controls were two knobs. There were no other controls. No start button. No open-door button. Both knobs felt Very Serious. There was no spinny platter thing, but it didn't seem to really do any worse than the new ones with it—but it was easier to clean. It was pretty big for a microwave.
One knob was power. One knob was a timer. You turn the timer knob to start it. It physically ticks down until it dings (real bell, not a speaker) and stops. You pull the (heavy) handle on the door to open it. It's secured with (I suppose) one or more of those mechanisms where a flared tab goes between a pair of little wheels, so it's secure unless you pull fairly hard, no need for a release button.
It was still mounted in the exact same place and working just as well as it did in the 80s and 90s, when my grandma moved out to live with my parents in the 2010s.
I've seen a few kinda similar models on offer, but they're expensive and without feeling one in person I really doubt they're actually as good.
(A bunch of the finishes on their very-modest poor-rural-town house—outlet and switch cover plates, some of the trim, the front door, the storm doors of all things, and the doorbell, were all luxury-tier by modern standards—some of those, I've never seen anything as good on any house built since 1970 or so, and I've been in some "nice" ones; some stuff's simply gotten worse, and I tell you what, the solid feel and butter-smooth action of some of those things really did make life better)