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From: ckaye@hemel.bull.co.uk (Chris Kaye)
Newsgroups: comp.os.msdos.programmer
Subject: Re: rebooting by a command, not by Ctrl-Alt-del or power off/on
Keywords: Reboot, clones
Message-ID: <1991Jan26.122142.9747@hemel.bull.co.uk>
Date: 26 Jan 91 12:21:42 GMT
References: <1991Jan10.013850.3506@cubmol.bio.columbia.edu> <1991Jan18.234616.18063@ncsuvx.ncsu.edu> <12503@ccicpg.UUCP> <1991Jan24.183619.11120@warwick.ac.uk>
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bsrdp@warwick.ac.uk (Hylton Boothroyd) writes:

>In article <12503@ccicpg.UUCP> mhr@ccicpg.UUCP (MHR {who?}) writes:
>> > > I want to know how to reboot an IBM pc not by Ctrl-Alt-del, power
>> > > off/on, or pressing the reset button methods. In other words, is
>> > > there a command I can issue to reboot the machine
>> > > -ping   ping@cubmol.bio.columbia.edu (128.59.128.3)
>> >
>> > bank@lea.csc.ncsu.edu
>>
>> Here is the assembly language code for both warm and cold boot
>> simulators.
>>
>> warm boot:
>> 	MOV	AX,0040
>> 	MOV	DS,AX
>> 	MOV	AX,1234
>> 	MOV	[0072],AX
>> 	JMP	FFFF:0000
>>
>> cold boot:
>> 	JMP	FFFF:0000

>Note that this advice depends on having:
>        * a true blue IBM PC,
>	* a clone in which the manufacturer's implementatation of BIOS
>	  code has emulated the true blue behaviour at FFFF:0000 .
>There appears to have been a period when some manufacturers felt it
>wiser not to emulate IBM warm boot too closely for fear of copyright
>action. The clone I use falls into that category.
>--
>Hylton Boothroyd        Janet: h.boothroyd@uk.ac.warwick.cu
>Warwick Business School Darpa: h.boothroyd%cu.warwick.ac.uk@relay-nsfnet.ac.uk
>University of Warwick   Uucp:  h.boothroyd@warwick.uucp
>COVENTRY, England       Earn/Bitnet: h.boothroyd%uk.ac.warwick.cu@UKACRL

Here is a 'C' version of a reboot program.
#! /bin/sh
# This is a shell archive.  Remove anything before this line, then unpack
# it by saving it into a file and typing "sh file".  To overwrite existing
# files, type "sh file -c".  You can also feed this as standard input via
# unshar, or by typing "sh <file", e.g..  If this archive is complete, you
# will see the following message at the end:
#		"End of shell archive."
# Contents:  rb.c
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f 'rb.c' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'rb.c'\"
else
echo shar: Extracting \"'rb.c'\" \(384 characters\)
sed "s/^X//" <<'END_OF_FILE' | ascbin >'rb.c'
X/*
X * Program to reboot PC.
X *
X * Arguments: nothing for cold reboot
X *            anything for warm reboot
X */
Xint far *loc = (int far *)0x472;
X
Xvoid (far *reboot)() = { (void (far *)()) 0xffff0000 };
X
Xvoid main(argc,argv)
Xchar **argv;
Xint argc;
X{
X	if (argc>1)
X		*loc = 0x1234; /* warm boot */
X	else
X		*loc = 0x0000; /* cold boot */
X	reboot();
X	/* Should not get here */
X	exit(0);
X}
END_OF_FILE
if test 384 -ne `wc -c <'rb.c'`; then
    echo shar: \"'rb.c'\" unpacked with wrong size!
fi
# end of 'rb.c'
fi
echo shar: End of shell archive.
exit 0
--
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Chris.Kaye@hemel.bull.co.uk  |
Bull HN Ltd., Maxted Road,   |
Hemel Hempstead, HP2 7DZ, UK |
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