This sort of behavior by teachers is exactly what got me to write my first serious z80 assembly program to mimic all of the menus on the TI-83 circa 1996. Teachers had already caught on to the fact that there were programs that would display the "Mem Cleared" message on the calculators, so mandated they had to do it manually. I never used my program to cheat, I just didn't want to lose my games (had a really good zelda clone & penguins).
