Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B UNSW 1.0 3/14/84; site qfdts.oz Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!genrad!panda!talcott!harvard!seismo!munnari!basser!uqcspe!qfdts!phil From: phil@qfdts.oz (Phil Chadwick) Newsgroups: net.unix-wizards Subject: Re: System V is Crashing Message-ID: <53@qfdts.oz> Date: Thu, 22-Aug-85 21:41:26 EDT Article-I.D.: qfdts.53 Posted: Thu Aug 22 21:41:26 1985 Date-Received: Mon, 26-Aug-85 01:31:34 EDT References: <666@brl-tgr.ARPA> Organization: Department of Forestry, Brisbane, Australia Lines: 31 In article <666@brl-tgr.ARPA> mlip@nadc.ARPA (Michael Lipczynski) says: >A colleague of mine is trying to bring up AT&T's UNIX System V on a VAX >11/780. Periodically, the system will crash and halt the CPU with the >following message: > >Machine software error: Protection violation on interrupt stack. Our VAX 750 runs System V release 2 version 2. I installed a new serial printer and the system crashed (with a protection violation as above) every time something was spooled to it. I was experimenting with the spooler interface program for this printer and changing the tty line paramaters with ioctl to some unusual settings. They were from memory: tio.c_iflag = IXON; tio.c_oflag = OPOST|ONLCR|NL1|CR3|TAB3|BS1|VT1|FF1; tio.c_cflag = B9600|CS8|CREAD; tio.c_lflag = 0; By using crash(1m) I discovered zillions of entries in the callout array which were to restart the printer's tty driver. I can't remember the exact circumstances, but I know that the callouts looked suspect and the use of fill characters (add OFILL to tio.c_oflag above) for delays rather than callouts cured the problem immediately. ---- Phil Chadwick Australia: (07) 2296500 Department of Forestry International: +61 7 2296500 PO Box 5 ACSnet: phil@qfdts.oz Brisbane, Roma Street ARPA: decvax!mulga!qfdts.oz!phil@UCB-VAX.ARPA AUSTRALIA 4001 UUCP: {decvax,vax135,eagle,pesnta}!mulga!qfdts.oz!phil