Old PDPs also have their fanbase, and there is a ton of knowledge floating around about all these systems, sometimes more in the hobbyist sphere than there is left at the companies that built them (assuming they still exist). Of course you could emulate it all but the real hardware has its own kind of charm.
I see this one is here in NL, maybe I'll ask the owner one day if I can come by to have a look at the beast, it is definitely an interesting era to document in living hardware.
https://github.com/open-simh/simh
And some software to run on it:
Most minicomputers landed in companies/departments too small to afford a mainframe and where used for inventory, POS, bookkeeping, payroll, etc.
In the mid-90's, they replaced it with PCs.
I learned COBOL (a adapted heavily scripted version of that) on a AS/400 used to control automotive operations in a factory.