I got a singing card a few days ago and when I finally tore it open i noticed 9 contacts I assume are for programming. They are labeled: a1, a2, a3, d1, pi, vss, vppx, d0, vpd. Does anyone know what they do and how I could use them to reprogram the music on the card? I'll try to post a pic as soon as I can find my camera. The PCB has opt4 v4 written on it, I can't find any info online.