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From: mull@sparc26.hri.com (Chris Mullendore)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: XT RLL HD cntlr doesn't work on AT clone?
Message-ID: <1991Feb25.232212.15139@hri.com>
Date: 25 Feb 91 23:22:12 GMT
Sender: news@hri.com (News Admin)
Reply-To: mull@hri.com
Organization: Horizon Research, Inc.
Lines: 19

I'm in the middle of upgrading my XT clone with a 286/20 NEAT
motherboard with Phoenix BIOS.  But, my XT RLL HD controller (Adaptec
ACB-2072) doesn't seem to work.  I admit I put it in a 16 bit slot, but
that shouldn't matter, should it?

Then I started looking at some documentation, and noticed that the AT
Bus has the hard disk interrupt request at IRQ14 where it was IRQ5 on
the XT bus.  Is there any chance that hacking my HD controller board to
use IRQ14 might work?  If so, could somebody please tell me how to
locate IRQ5 and IRQ14 on the AT I/O card connector?

Or are there other changes in the way an AT handles an HD controller
such as trying to do 16 bit transfers that would screw me up?  I really
don't care about performance.  8 bit transfers would be fine for now. 
My M/C's at the limit and a new AT RLL controller doesn't seem cheap.

Any help would be greatly appreciated.

Chris Mullendore (mull@hri.com)