Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!samsung!uunet!crdgw1!sixhub!davidsen
From: davidsen@sixhub.UUCP (Wm E. Davidsen Jr)
Newsgroups: comp.sys.ibm.pc
Subject: Re: MFM on RLL?
Message-ID: <645@sixhub.UUCP>
Date: 17 Mar 90 21:51:53 GMT
References: <2881@uwm.edu> <148@cms2.UUCP>
Reply-To: davidsen@sixhub.UUCP (bill davidsen)
Distribution: all
Organization: *IX Public Access UNIX, Schenectady NY
Lines: 23

In article <148@cms2.UUCP> tomf@cms2.UUCP (PUT YOUR NAME HERE) writes:

| Mark,
| An MFM controller formats to 17 sectors per cylinder. An RLL formats to 34
| sectors per cylinder. It also increases the number of cylinders per platter.

  MFM is 17 sectors per track, RLL is 26 sectors, ARLL is 31, ERLL is
34. As far as I know only Perstor is selling commercial controllers
which do more than 26. This is why you went from 21MB to 32MB instead
of 42MB. I have never seen any claim of added cylinders, not any sign of
it in terms of capacity. Please state a source for this enlightening
information.
  
|                I have formatted a Seagate ST-225 (MFM, 21MB) with an RLL
| card to 32MB. It stored data without error and still runs today. But I keep
| it all backed up, understanding the risks involved.

  Your information seems to confirm what I said.
-- 
bill davidsen - davidsen@sixhub.uucp (uunet!crdgw1!sixhub!davidsen)
    sysop *IX BBS and Public Access UNIX
    moderator of comp.binaries.ibm.pc
"Getting old is bad, but it beats the hell out of the alternative" -anon