I first learned assembly language on a computer similar to this: http://www.computercloset.org/SmokeSignalChieftain.htm though it had a 6809 processor. School had a lab full of them. Completely stand-alone of course, to print you had to take a floppy disk over to the one machine that had an attached printer. Spent many late evenings there.
[0] https://en.wikipedia.org/wiki/MOS_Technology_6502