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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.ecn.uoknor.edu!feed1.news.erols.com!howland.erols.net!rill.news.pipex.net!pipex!server1.netnews.ja.net!warwick!bham!aston!not-for-mail From: dimmicmj@aston.ac.uk (Michael Dimmick) Newsgroups: comp.unix.advocacy,comp.unix.bsd.freebsd.misc,comp.os.linux.advocacy,comp.os.linux.misc Subject: Re: ( FreeBSD > root < Linux ) > /dev/flame Date: 24 Apr 1997 12:14:07 GMT Organization: Aston University Lines: 27 Message-ID: <5jniqf$432$2@whatsit.aston.ac.uk> References: <33513993.167EB0E7@sarenet.es> <5iruhb$rde@idiom.com> <slrn5l673t.4k.c_chaos@chaosnet.wahnapitae.on.ca> <5j2n3u$54p@idiom.com> <5j4c4b$sjc$4@easystreet03> NNTP-Posting-Host: rwanda.aston.ac.uk X-Newsreader: knews 0.9.6 Xref: euryale.cc.adfa.oz.au comp.unix.advocacy:39748 comp.unix.bsd.freebsd.misc:39670 comp.os.linux.advocacy:94575 comp.os.linux.misc:171717 In article <5j4c4b$sjc$4@easystreet03>, tedm@portsoft.com writes: >In <5j2n3u$54p@idiom.com>, jsi@idiom.com (Michael Craft) writes: >>It goes into 286 protected mode, I guess? The real mode is just no >>good. >Not necessairly, the '286 had the secret loadall instruction, used by >the DOS 3.3 version of ramdisk, the IBM version of vdisk, and the DOS >version of himem.sys. Since the '286 could only return from >protected mode by resetting the CPU, and real mode could only address >the bottom 1 meg, didn't you ever wonder how you could access "XMS" >memory on a 286 under DOS? ;-) ISTR there's a kludge in the keyboard controller, or something, that could be called with an I/O port addressing which would crash the processor, whose watchdog timer would then reset it, with a special recall routine in the BIOS that would then jump back to the right real-mode section. Ouch. I also recall that it was bloody slow! I used to have a 286 with MS-Windows on it (v3, then v3.1) and closing down a Windows session would take a couple of minutes... -- Michael Dimmick | dimmicmj@aston.ac.uk | http://www.aston.ac.uk/~dimmicmj ".sig, .sig, wherefore art thou .sig?"