Maybe I was unclear on what I meant by "jumpering across": you put a wire between pin 1 and pin 3 of the regulator. With such a jumper, it's impossible for the input to drop below output at the regulator. Of course, you've got to remember to remove the jumper before putting the resulting card back into a system with unregulated power busses! Like I said, regulated S-100 power busses were done by several manufacturers in the early and mid-80's with great success. It's a non-issue. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927