Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!ucsd!ames!hc!lll-winken!uunet!datapg!com50!kksys!gk
From: gk@kksys.mn.org (Greg Kemnitz)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Booting off 1 hard drive and not the other
Message-ID: <1210@kksys.mn.org>
Date: 23 May 89 05:11:11 GMT
References: <8275@pyr.gatech.EDU> <8938@xanth.cs.odu.edu>
Reply-To: gk@kksys.UUCP (Greg Kemnitz)
Organization: K and K Systems, Minneapolis MN
Lines: 36

In article <8938@xanth.cs.odu.edu> rlb@cs.odu.edu (Robert Lee Bailey) writes:
>In article <8275@pyr.gatech.EDU> ccastgw@pyr.gatech.edu (GREG WILLIAMS) writes:
>>I have two hard disks on my PC/XT clone.  One is an ST-238R and the other
>>is an ST-251N (SCSI).  Currently my PC boots off the 238.  I would like to
>>fix it so that I boot off the 251.  I looked at the addresses for the 2
>>drives using debug.  The 238 is at C800 and the 251 is at CA00.  I am
>>assuming that whichever drive is at C800 is the one booted from.  Is
>>this true?  If so, how do I switch the 2 addresses to boot from the 251?
>
>Sure, just swap the cables between the two drives!
>
>	Bob Bailey

This suggestion will *NOT* work.  The drives he has are on *separate*
controllers -- the ST-238R is a ST-506 interface RLL drive, while the
ST-251N is a SCSI interface drive.  The controllers are NOT the same!

Although I have not encountered the above situation before, the
original theory presented by Mr. Williams sounds plausible (switch the
controller rom addresses).  Unfortunately, without information on
which controllers he is using it will be difficult to provide him with
the needed information.

Another possible approach would be to format the ST-238R without a dos
system image.  Theoretically, at boot it would scan the ST-238R, find
no boot image, and then scan the ST-251N (it is likely the first drive
on its controller, and thus would be scanned for boot).  If the
ST-251N *did* have a boot image, the system would boot from it.

Disclaimer:  The above has not been tested, however I have seen at
least one bios which booted in this manner.  Your mileage may vary.

-- 
Greg Kemnitz / K and K Systems / PO Box 41804 / Plymouth, MN 55441-0804
Domain: gk@kksys.mn.org / UUCP: ...!{amdahl,hpda}!bungia!kksys!gk
Voice:  +1 612 475 1527 / Fax:  +1 612 475 1979 - touch '1' at second ring