Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site sdchema.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxl!ihnp4!zehntel!hplabs!sdcrdcf!sdcsvax!sdchema!sd From: sd@sdchema.UUCP (Steve Dempsey) Newsgroups: net.unix-wizards Subject: stray nexus (TR 00) interrupts on Vax 780 Message-ID: <220@sdchema.UUCP> Date: Tue, 21-Aug-84 16:06:07 EDT Article-I.D.: sdchema.220 Posted: Tue Aug 21 16:06:07 1984 Date-Received: Thu, 23-Aug-84 02:01:08 EDT Organization: U.C. San Diego Chemistry Dept Lines: 16 Here in the UCSD Chem. dept. we have recently brought up 4.2bsd on a VAX 11/780. With varying frequency we are seeing the following message on the console: nexus stray intr ipl16 Perusal of the kernel source code and the VAX HARDWARE HANDBOOK 1980-81 reveals that the CPU is detecting an SBI interrupt at level 16 from the nexus at TR 00. This same book also reveals that no nexus is ever assigned to level 00. It is reserved for a holding signal that is guaranteed to be at a higher priority than any other nexus. We have a Floating Point Systems AP-120b array processor on uba0 (TR 3) at the indicated level (ipl16, br6 to PDP UNIBUS fans). Any ideas as to who or what could be generating the phony interrupt?