From: Iggy Drougge <optimus(a)canit.se> What makes PCs complex is the standards creep, since most PC standards were ignored or poorly implemented things that should work often didn't or did only after a fashon. For vaxen especally the Qbus models the ruls were very narrow and it was enforced internal to DEC and Protocals like MSCP were patented if a third party wanted to do it it's implementation was generally good. Now the likely thing is you either did an ESD hit to something or while pushing/pulling something you may have altered a switch, jumper or maybe puped a chip loose. Allison