Not sure what you're looking for here, hardware or software? Seems to me any S/W not using CB2 would require _some_ kind of special hardware, however trivial. At least 2 come to mind, the Petunia, and the MTU 4 voice/16 harmonics systems for both PETs and KIM/SYM/AIMs; is one of these what you're thinking of? The cheap & dirty method was just a resistor ladder across the parallel interface as a D/A converter; might still have one of these & some S/W, but don't hold your breath, haven't looked at the CBM pile in ages. Hmmm... just ran across an old ad for an accounting package for a KIM/SYM; wouldn't you have enjoyed being the data entry operator for that? Think I'd prefer even a Windows package... -------------Original Message---------------- From: Ethan Dicks &lt;erd_6502(a)yahoo.com&gt; <snip> ObClassic: Does anyone have any software for making music on the PET with *other* than CB2 sound? I had a buddy with a clip-on user port music card - it was an 8-bit D-to-A like a Disney Sound Source. The PET shoved bytes out the user port and they appoximated music. I can't remember what it was called.