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From: jca@pnet01.cts.com (John C. Archambeau)
Newsgroups: comp.sys.ibm.pc
Subject: Re: RLL controllers with MFM drives
Message-ID: <646@crash.cts.com>
Date: 5 Nov 89 05:16:08 GMT
Sender: root@crash.cts.com
Organization: People-Net [pnet01], El Cajon CA
Lines: 31

perry@ccssrv.UUCP (Perry Hutchison) writes:
>I asked this once before, but now that we have someone with direct Seagate
>knowledge maybe we can get a semi-authoritative answer.  It's pretty clear
>from previous postings that using RLL on a drive not designed for it is
>not always going to work, and one can therefore not expect a manufacturer
>to warrant the results.
>
>What I don't see is why Seagate objects to MFM formatting of an RLL-rated
>drive.  Obviously it reduces the capacity by 1/3, but if someone wanted to
>do it, would it really impair the reliability so as to justify voiding the
>warranty?
 
I don't know the exact reason why.  I do know that somebody posted here that
he formatted an RLL drive MFM and it didn't quite work the way it was supposed
to.  I do know Seagate's warranty policy well and I follow it to the letter. 
It might deal with the fact that an RLL drive is designed to do a 7.5 Mbit/sec
transfer and an MFM drive is only 5.0 Mbit/sec.  But I do know that it is
documented on page 6 of the Seagate Universal Installation Guide.  The
copyright date on it is '87, but we have been getting this installation
booklet with every drive we have ordered.

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