Yes I would build a device for that cheap. I failed to make my specifications detailed enough as you point out, Robert. I want a speed of 10 Hz and a depth of one. Thus I can single step my process or halt it and see what is going on. I was not looking for a trigger or anything like that. AGSC At what speed, with what memory depth? There are a few free PC based programs that use the parallel port, but I doubt you'll find ANYTHING hardware based for $50.00. Would YOU build and sell such a device for that cheap? R From: Robert Rolf -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist