Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!samsung!uunet!crdgw1!crdos1!davidsen
From: davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Two Hard Disk Controllers in One Machine
Message-ID: <1539@crdos1.crd.ge.COM>
Date: 3 Nov 89 15:33:34 GMT
References: <1092.25455B8D@busker.FIDONET.ORG> <4333@ncsuvx.ncsu.edu> <[2769.4]comp.ibmpc;1@point.UUCP>
Reply-To: davidsen@crdos1.UUCP (bill davidsen)
Organization: GE Corp R&D Center
Lines: 23

In article <[2769.4]comp.ibmpc;1@point.UUCP>, wek@point.UUCP (Bill Kuykendall) writes:

|  Have you actually done this, or is this conjecture?  I have serious doubts
|  that any flavor of MS-DOS will bother to look for a second controller.

  I haven't looked at this recently, but MS-DOS doesn't look for a 1st
controller. The ROM BIOS looks for a magic byte pattern in the space
from (roughly) A000:0 up. If it find the pattern it jumps to the ROM at
that location. This is how video cards, disk controllers, etc, are
located. If a 2nd controller can relocate it's BIOS so it doesn't
interfere with the first, and is in the right place, then it should
work.

  This has nothing at all to do with DOS, note that an IBM PC will come
up in BASIC with no disk. Obviously it found the video adaptor... If
your system doesn't have ROM BASIC it will do something else, like tell
you to insert a disk.

-- 
bill davidsen	(davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen)
"The world is filled with fools. They blindly follow their so-called
'reason' in the face of the church and common sense. Any fool can see
that the world is flat!" - anon