Changing the size of memory or changing the ROM version forces a reset of the PET.
The emulator has an IEEE-488 device at address 8. It can be used load and save (.prg) files.
Some programs don't run on ROM1 and some require more memory than the default 8K.
PIEGRAM is not a pie chart graphing program; it is a hide and seek game where you and the PET take turns taking shots at each other as you move around a 10x10 grid. For each shot you take, the computer reports the distance to the target of your three most recent shots. If you have a good handle on the Pythagorean theorem, you should be able to zero in on your quarry efficiently. The computer isn't especially smart either. I was sure it had me cornered at one point—two shots in a row landed 1 square diagonally adjacent to my position but the PET failed to take advantage of that information.