"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. "
DEMO TUNE: http://petsynth.org/music/petsynth_demo_1.mp3
WEBSITE: http://petsynth.org/