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.
DOTS is a computer version of the pencil-and-paper game of the same name. You and the computer alternate turns connecting adjacent dots. Every time you surround a square, you earn a point and take another turn. The computer opponent is not too bad—it's strong enough to punish careless mistakes but a thoughtful human player should be able to beat the computer if they play well.
The computer takes a while to take its turn but displays a cool PETSCII wave animation while it is thinking. If you're playing on an emulator, warp mode is your friend. If you don't mind the computer taking extra time, you can configure the size of the board with larger dimensions.
It seems that 8x8 is the largest board that the 8K PET can handle without throwing an ?OUT OF MEMORY ERROR.