Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!blake!djo7613
From: djo7613@blake.acs.washington.edu (Dick O'Connor)
Newsgroups: comp.sys.ibm.pc
Subject: Adding a second hard disk to an AT
Keywords: Second hard disk, AT, two controllers
Message-ID: <2609@blake.acs.washington.edu>
Date: 30 Jun 89 15:01:51 GMT
Distribution: na
Organization: Univ of Washington, Seattle
Lines: 40


Apparently a consultant who used to work here left one of our divisions
with a hard disk he promised to add to an AT with an existing HD.  Details
are scanty, cables seem to be missing, and I have a couple of questions
maybe some of you HW types can answer why I scramble to make something
of this mess.

I'm familiar with my own setup: one hard disk, one controller board, two
cables (one wide, one narrow, one called "data", other called "signal" I
*think*).  The controller in the AT right now is the same as mine: an
RLL board driving a Seagate ST238R, 30MB, 65ms.  The hard drive they want 
to add is a Micropolis model of uncertain lineage (I can take another look
for a model number).  The new controller apparently can handle two drives
(two narrow connectors, one wide; why is that all that's needed, BTW?), but
I can't find any identifying marks on it and I wouldn't know an MFM board 
from an RLL board if it bit me in the foot.

If we discover that it's an RLL board, can we run two drives off it in an
AT even if the drives themselves have differing rated access times?  If it's
an MFM board, can two such boards (MFM and RLL) coexist in the same AT
(actually clone I should say) and drive two different HD's?  That doesn't
sound possible.  And finally, could we low-level reformat the Seagate with
the new controller (if it's MFM), take the drop to 20 MB, and run the
two drives?

Gee, just when you think you start to know something about this wacky
business, someone comes up with something *new*!

P.S. We can't find any cables with the new drive (sigh).  What's needed to
make things work here, another narrow cable?  Are identical cables used
for MFM and RLL and ??? hard disks?  

"Moby" Dick O'Connor
Washington Department of Fisheries
Olympia, Washington  98504
Internet Mail: djo7613@blake.acs.washington.edu
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DISCLAIMER:  I speak only for myself, not for the Department.  Here, anyway!
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               So long, and thanks *from* all the fish...