Many thanks to all of you for the excellent suggestions! The rollers were pristine, but the ball was slick. I ended up cleaning the ball with Rubbing Alcohol to get it clean, then scrubbing it with a scouring pad (since i couldn't find sandpaper) to give it a little more bite. It works perfectly now! Thanks again to y'all!
For what it's worth, I'm getting my Amiga 1000 + Genlock set up for Barcamp Rochester, this Saturday, so that people can draw over live video of themselves, then have it automatically post screenshots (via my DV Camcorder + eyefi sd card) to a tumblr blog... here's some test output from it:
http://amigapics.tumblr.com/ I'll probably write up a full blog post about it when it's done. It's a smörgåsbord of old tech mashed together for fun!
