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.
CURVES uses the quarter-square PETSCII graphics characters to plot mathematical functions expressed in polar coordinates. The program draws two kinds of graphs: hypocycloid curves (the kind that you'd get by playing around with a Sprirograph toy), and trigonometric curves. The calculations are slow in BASIC but if you're patient, the end results are quite pretty.