Hello and welcome!
This is the official project page for PetSynth - the only program for rocking the Commodore PET that the cool kids use.
Update: I've added an audio file in .FLAC format that you can download and record to a tape file and use on a real PET. See the guide for details.
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.
All this without adding or hacking the Commodore PET in any way. Plus, it's compiling from C, so it's FAST - with very low latency.
This computer does not use a SID 6581 music chip at all! This program was designed, tested, and refined on a real life fully working stock Commodore PET 4032 computer, and the sound is heard coming out of the built-in piezoelectric on the PET 4032 . It does not involve hacking the computer in any way, or adding any extra sound cards. It does not involve taking sound from the tape port. It also does not implement a DAC to create sounds.
It's also GNU GPL v2 open source software - so if you like it, you can go hack it yourself. Or pay someone to make it the way you want it. Like me ;)
There's nothing that sounds quite like it. It's got a huge sound, and no noise. Really, when I plug it into my mixer, there's no noise at all! I can hardly find any no matter how high I turn it up!
The drum sounds are also crazy weird. You can also set the vibrato so high it sounds more like a laser gun or alien telephone.
All this from the finest in 1-bit sound on the Commodore PET.
I hope you have as much fun playing it as I do!