Both work, but if you have not started, I would recommend to use the latest V3.0 listing. The v3.0 mouse version is actually a little bit shorter than the v2.1 listing because of some optimizations and it makes sure you have enough BASIC memory left in case you would like to experiment and/or add your own optimizations. And for the mouse version you can omitt the joystick replacement code on page 5. The Joystick part is not additional but replacing parts of the program. I hope that helps.