When I was serving the military back in 2002-2003, in one of the classrooms they had a couple of Pravetz-82's (Apple II clones) that were still functioning.
The schools and the military are very conservative and they use 20-30 years old technology without any trouble if they work well. They don't have problem with the spare parts as they have a load of these machines. Too bad the Amiga back in the Commodore days didn't went for that market and it was taken over by Apples and cheap IBM PC XT/AT clones. I know some C64 were used in classrooms as well.