Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!cs.utexas.edu!samsung!usc!apple!vsi1!octopus!pete
From: pete@Octopus.COM (Pete Holzmann)
Newsgroups: comp.sys.ibm.pc
Subject: Re: RLL controllers with MFM drives
Message-ID: <1989Nov2.221948.5629@Octopus.COM>
Date: 2 Nov 89 22:19:48 GMT
References: <89102911043898@masnet.uucp> <1514@crdos1.crd.ge.COM> <1989Oct31.224410.272@rand.org>
Reply-To: pete@octopus.UUCP (Pete Holzmann)
Organization: Octopus Enterprises, Cupertino CA
Lines: 29

In article <1989Oct31.224410.272@rand.org> edhall@rand.org (Ed Hall) writes:
>Well, when I tried to reformat my year-old ST-4096 with a WD-1006V-SR2
>controller (a 1:1 RLL controller), just about *half* (50%) of the
>tracks came up bad, according to WD's ROM-based formatter....
>So, I popped back in the old WD MFM controller and reformated.  ZERO
>bad tracks!...
>Perhaps I should post to alt.conspiracy.  I've certainly read of
>ST-4096's running RLL.  I might just be unlucky.

These symptoms are very similar to what I saw the one time I had a drive
that simply refused to 'take' RLL. In my case, it was certified for RLL,
so I just yelled until I got a replacement. (It was actually pretty tough-
the distributor had an MFM tester, not an RLL tester. The drive worked 
perfectly under MFM; I had a time convincing them it was bad!)

I never got a truly satisfactory answer out of the manufacturer's field
engineer. Supposedly it had something to do with a portion of the mechanical
assembly not being tightened down quite enough; the drive would eventually
have failed under MFM also. By the way, it had a huge pile of defects listed
on its RLL defect map also. I suppose I should have been suspicious from the
start!

Pete
-- 
Peter Holzmann, Octopus Enterprises   |(if you're a techie Christian & are
19611 La Mar Ct., Cupertino, CA 95014 |interested in helping w/ the Great
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