Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!ucsd!ucsdhub!loral!jcb
From: jcb@loral.UUCP (Jay Bowden)
Newsgroups: comp.sys.ibm.pc
Subject: SCSI hard card will boot in AT, but not in XT
Keywords: MDI WARP DRIVE HARDCARD
Message-ID: <2454@loral.UUCP>
Date: 15 Mar 90 16:21:53 GMT
Organization: Loral Instrumentation, San Diego
Lines: 43

Help!  I have an old (1986?) Hard disk card.  Sort of a strange one, it
is an Micro Design International "WARP DRIVE" 21 MB SCSI-interfaced
hard disk on a card.  I originally used it in an XT I am sure, but then
I moved it to an AT, and was quite pleased when I got an AT, and was
able to plug it right in and it booted.  I realize that I do not have
the advantage of 16 bit transfers, and the hardcard always was
relatively slow, so I have now put an AT-class drive and controller in
the AT.

I want to plug the hardcard into an XT, and give it away to a friend.
But it don't boot!  Infact, it hangs up in the cold boot process, and
after the RAM test, it never comes back, not even with a disk error!

Plug it back into the AT, and it boots fine!

Plug it into a different XT (but w/the same motherboard mfgr),
and it hangs up.

Plug it back into the AT, and it boots fine!

Plug it into the XT, with a different BIOS chip, and it hangs
up.


I've tried each of the DMA channels, including the "pseudo DMA" option
(program controlled port IO, I suppose) the card supports, but it still
locks up.  I've tried moving the disk ROM from D800:0 (its default) to
C800:0.  Either way, it boots fine in the AT, but hangs up in the XT.


What am I missing?  Anyone have a clue? Solve this and you
will have my eternal gratitude, as well as that of the person
I want to give the PC to!

Thanks!

- Jay

-- 
------------------------------------------------------------------
Jay Bowden, EE/Consultant; see also Bowden Engineering
Currently contracted at Loral Instrumentation, San Diego
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