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.
ADD is a simple addition drill program. You enter the sum one digit at a time from right to left, entering any carries as you go. This program is a solid way to brush up on addition, and the visual indicator for each carried digit is useful. You can specify the size and number of the addends, all the way up to problems where you have to add nine random nine-digit numbers, which becomes much easier with the one digit at a time input.