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From: purkers@jacobs.CS.ORST.EDU (Scott Purkerson)
Newsgroups: comp.os.coherent
Subject: Re: ST1144A or CP30104
Message-ID: <1991Apr30.223206.10229@lynx.CS.ORST.EDU>
Date: 30 Apr 91 22:32:06 GMT
References: <1991Apr24.201053.12622@lynx.CS.ORST.EDU>
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Distribution: comp.os.coherent
Organization: Oregon State University, CS Dept.
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In article <1991Apr24.201053.12622@lynx.CS.ORST.EDU> I wrote:
>
>Earlier there was discussion about the Seagate ST1144A
>hard drive; I'd like to get mail from people who have actually
>installed Coherent on one...[stuff deleted]
>
>I'm also thinking of buying a Conner CP30104 (instead of the 1144)...
>[stuff deleted]
>
>Last of all (but perhaps most important), I've heard that using IDE
>drives may be a little trouble...
>[stuff deleted]
>...I will post a follow-up article with info that I receive.
>

[special thanks to Robert K. Hamilton, David Baldwin, Michael L. VanLoon
and John Winans for the following information. :-)]

There were three replies about the Seagate ST-1144A and one about the
Conner CP30104.

Evidently,  MWC has special instructions for installing Coherent
with the ST-1144 that you can request.  It sounds
like there are two requirements for installation and maybe a third:

	1. You need Coherent 3.1.0 or later.
	2. You need a user configurable BIOS
	[ 3. You may need to have AMI BIOS {4/9/90 or later}, but
		I know that Award has a user configurable BIOS
		{version 3.10 or later} that may or may not work.
		There are probably others.]
		(Maybe someone can give more exact information about this!)

The drive parameters used for AMI BIOS are:
	Drive Type:	47 (user defined)
	Cylinders:	1001
	Sectors/Track:	17
	Write precompression cylinder:	1002 (disables)
	Control Byte:	0

Therefore, it shouldn't be too difficult to install Coherent
on the ST-1144A as long as you have a user definable AMI BIOS.


The Conner CP30104 drive sounds like it has a good probability of 
working with Coherent.  [A note of general info: the CP30104 is a 
small, thin 120MB drive that must have just recently been released
by Conner. Like the ST-1144A, it has a 19ms av seek time.  The CP3104
is a 25ms, 100MB drive which is also small, quiet and fast.]  Although
the reply to me was about the CP3104, the person states he was able to run
DOS, Coherent, and SCO Unix without any hardware or software problems.
He mentioned that his BIOS is user definable, but didn't give the
brand name (AMI? Award?...).

A couple people discussed IDE drives in general to answer my question
about being able to delete Coherent if I didn't want to use it 
anymore ;-).  I see now that you can reformat your IDE hard drive
any way you like using the high-level format, but you must not
use the low-level format.  A recent article about the IDE interface
is in the May 14, 1991 issue of PC Magazine (Vol. 10, No. 9, p. 379)
by Winn L. Rosch.  This seems to be a very good reference for
understanding the IDE standard in general because it answers many of
the confusing questions people have brought up in the past (i.e. self-
adjustment to BIOS config; IDE versus ESDI, RLL, MFM, SCSI in speed;
etc...).

As to which HD I chose to buy -- I chose the Seagate 1144 because
my distributor told me very few ever come back for repair.  Although
the Conner CP3104 seems to have a good record, the CP30104 seems to
be relatively new on the market.  I wanted proven reliability; the 
Seagate cost slightly more, but had slightly less $/MB ratio.

I hope this follows up my previous request for information well
enough.  I'm definitely not an expert, but I will answer any questions
if you want to email me.

Thanks to all the people who replied! :-)
--
"You cannot build character and courage by taking away man's
   initiative and independence." --Abraham Lincoln

purkers@jacobs.cs.orst.edu