Well, I finally got my hands on one of these tools, and opened it up in anticipation of a relatively simple system to make repros of. Argh...there are about sixty TTL chips and op amps in this sucker! Single sided circuit board with a bunch of parallel jumper wires for the top traces. Nasty. No schematic. No labels. Looks kinda cobbled together as they would have been rather low run production. Damn. I am NOT going to try to make any more of these things. Turning in Clay's direction...This thing has three speeds on in, 65ms, 130ms and 260ms (or close might have been us ...the thing is at the shop and it's two days later since I stared at it) and it has full screen, crosshatch and one other pattern, plus you can turn off individual guns. Perhaps someone could make a single chip do this job? Not me. I can get better info on timing etc if someone else wants to tackle the design... John :-#(# John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) http://www.flippers.com "Old pinballers never die, they just flip out."