"Hello and welcome!
This is the official project page for PetSynth - the only program for rocking the Commodore PET that the cool kids use.
I've been sitting on this for a year, and I decided that it was finally time to unleash this puppy upon the world!
It features a two-octave keyboard layout, selectable note length, many selectable octaves, selectable pulse-width, vibrato, distortion, and noise or "drum mode" depending on how you use it." See http://petsynth.org/ for more.
"I've written software that turns an old Commodore PET into a playable synth. I've created the above website and have released it as open-source software, so anyone can download it, use it, and modify it if they're interested."
Update: "Just an FYI - I updated the site - it now has a FLAC version of the program for audio tapes, so people with a datassette can download and record the program to tape - without having to download the disk version and convert it."