The userland DoS I remember: main() { while(1) fork(); } And in fact I tried it once on the 11/45 I had access to. Not pretty. It can be made less disastrous by judicious addition of a wait(); call. --Milo, wondering how contemporary UNIX will deal with such pathological behavior.... -- Milo Velimirović University of Wisconsin - La Crosse La Crosse, Wisconsin 54601 USA 43 48 48 N 91 13 53 W -- There's a reason Dennis Ritchie and Ken Thompson have been awarded the U.S. National Medal of Technology (1998) and are fellows of the Computer History Museum Online. Dave Cutler hasn't and isn't. "You are not expected to understand this."