@NanoRaptor It's been a few years ago, now, but there was a famous job ad floating around. It was from General Electric, recruiting PDP-11 programmers.
It was cheaper to hire such a person, than to retrofit a more modern processor to their *checks notes* nuclear power plants.
Outside of that, I'd guess it might be the flight management computer in an early-1980s aircraft, that's never been upgraded. The pilot has to remember to look under "Yugoslavia" if they want to fly to Belgrade, or "East Germany" if they want to fly to Berlin.