While I was building my companies, I had a project to create a little microcontroller-based trainer that was programmed in a combination of LISP and raw assembler. It has possibilities, but I couldn't convince the money people that it had "legs" as a mass-market product. I agree that it's a better way to teach math and logic and the underlying basis of language than the gut-rotting conditioning that goes on in public schools!

A 6502 is pretty low on the totem pole, although with a whole Apple you have some capability. See if you can get an Atmel Butterfly (~ $20).