I get a free mag called PT Motion that deals with, what else, motion and motion control. They have some interesting articles, and also have a web site that covers some of the same material. On article of interest this month was called "Twenty Minute Tune Up". This deals with PID and the theory behind it and some tips on how to use it. They have a free program to download that lets you play with PID system and tune for proper operation. The web site is free and you can subscribe to the magazine there as well. Last month had an article "taking a bite out of backlash" The web site is http://www.penton.com/ptd/index.html . Check it out if you deal with motion control systems. David V. Fansler Network Administrator AutoCyte, Inc. 800-426-2176 Ext. 261 dfansler@autocyte.com Now Showing! http://www.mindspring.com/~dfansler Last Updated On March 29,1999 Opinions Expressed Within Are Mine And May Not Reflect Those Of My Employer