From: Juliusz Chroboczek Newsgroups: comp.os.linux.x,comp.os.linux.misc,comp.os.linux.development.apps,alt.folklore.computers Subject: Re: Magic SysRq (was Re: Linux has finally crashed) Followup-To: alt.folklore.computers Date: 01 Aug 1999 22:46:00 +0100 Organization: Division of Informatics, The University of Edinburgh Lines: 20 Message-ID: References: <7nn2o9$u13$1@nnrp1.deja.com> <37A07139.33ECC197@math.nwu.edu> <7nq6lb$ic1$1@lycaeus.calstatela.edu> NNTP-Posting-Host: muck.dcs.ed.ac.uk Mime-Version: 1.0 (generated by tm-edit 7.104) Content-Type: text/plain; charset=US-ASCII X-Trace: kane.dcs.ed.ac.uk 933543970 5354 129.215.160.15 (1 Aug 1999 21:46:10 GMT) X-Complaints-To: abuse@dcs.ed.ac.uk NNTP-Posting-Date: 1 Aug 1999 21:46:10 GMT X-Newsreader: Gnus v5.3/Emacs 19.34 Cache-Post-Path: muck.dcs.ed.ac.uk!jec@iolla.dcs.ed.ac.uk X-Cache: nntpcache 2.3.3 (see http://www.nntpcache.org/) Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.ifi.unizh.ch!news.rhein-neckar.de!news-fra.maz.net!newsfeed.tli.de!newsfeed.icl.net!nntp.news.xara.net!xara.net!server6.netnews.ja.net!newsfeed.ed.ac.uk!kane.dcs.ed.ac.uk!not-for-mail In article , pdarnows@qis.net (Philip W. Darnowsky) writes: PWD> This does sound pretty cool, but what I wanted to know was if anyone knew PWD> what the *original* use of SysRq was and how it got onto the keyboard on PWD> the first place. Even scroll lock I understand (and use), but SysRq? Who PWD> knows? What happens if, for instance, you hit SysRq on a Windoze box? Or PWD> on this O2 I'm on? Let's find out. Not much, apparently. I believe that on the original IBM PC/AT, the SysRq key would generate interrupt 0x14. Which would immediately return. I believe the feature was there for the exclusive use of IBM's proprietary synchronous-serial-line-cum-pagemode-terminal-emulator extension card, but I wouldn't swear about it. Followups to alt.folklore.computers. ###### From: cbh@REMOVE_THIS.teabag.demon.co.uk (Chris Hedley) Newsgroups: alt.folklore.computers Subject: Re: Magic SysRq (was Re: Linux has finally crashed) Date: 2 Aug 1999 10:35:27 GMT Organization: Honest Chris' Sysadmin Emporium Message-ID: <7o3s9f$33k$1@teabag.demon.co.uk> References: <7nn2o9$u13$1@nnrp1.deja.com> <37A07139.33ECC197@math.nwu.edu> <7nq6lb$ic1$1@lycaeus.calstatela.edu> NNTP-Posting-Host: localhost X-NNTP-Posting-Host: teabag.demon.co.uk:193.237.4.110 X-Trace: news.demon.co.uk 933591579 nnrp-14:16638 NO-IDENT teabag.demon.co.uk:193.237.4.110 X-Complaints-To: abuse@demon.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii NNTP-Posting-Date: 2 Aug 1999 10:35:27 GMT X-Newsreader: knews 1.0b.0 Lines: 14 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!news-fra1.dfn.de!news0.de.colt.net!colt.net!dispose.news.demon.net!demon!news.demon.co.uk!demon!teabag.demon.co.uk!localhost!not-for-mail In article , Juliusz Chroboczek writes: > I believe the feature was there for the exclusive use of IBM's > proprietary synchronous-serial-line-cum-pagemode-terminal-emulator > extension card, but I wouldn't swear about it. Not sure of its original purpose, possibly to aid terminal emulation, or maybe they had a use for it akin to whatever mainframes did with their sysreq key (the ones I used generally seemed to drop back to NETMON or whatever it was called temporarily when it was pressed; I can remember using this for several things, ISTR the most common was to disconnect "hung" sessions) Chris.