via bigmech.com where you'll find the instructions.
"Since the C64 is an 8-Bit system, and the SID is controlled by 8-bit values generated by the C64, it has gained popularity among a community of musicians who utilize 8-bit technology in order to create modern music containing sounds reminiscent of 1980's video games (8-Bit Music). However, the sound of the SID chip is far from limited to bleeps and blips.
In early June, 2006 Prophet64 made the bold move of releasing its SID music software on C64 cartridges. This completed the transition of the C64 from a computer system dependant on floppy and/or tape drives, to an independent piece of pro audio studio equipment. Could the union of Prophet64 with the C64 as a musical instrument be further improved upon? I thought so. The following pages explain what I have done.If you decide to perform these mods to your C64, I recommend that you do so one at a time, stopping to test each mod as you progress. It’s also a good idea to do them in order. You don’t want to create a difficult situation such as removing the original video connector before you have the S-video mod working."
via AlphA in the comments of this post.
