Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!cs.utexas.edu!samsung!usc!snorkelwacker!mit-eddie!uw-beaver!ubc-cs!fornax!chapman
From: chapman@fornax.UUCP (John Chapman)
Newsgroups: comp.sys.ibm.pc
Subject: Re: MFM as an RLL drive?
Summary: mine works
Message-ID: <272@fornax.UUCP>
Date: 4 Feb 90 06:36:19 GMT
References: <90011904272373@masnet.uucp< <MLM.90Jan21115353@hector.cs.brown.edu<
Distribution: na
Organization: School of Computing Science, SFU, Burnaby, B.C. Canada
Lines: 38

In article <MLM.90Jan21115353@hector.cs.brown.edu<, mlm@cs.brown.edu (Moises Lejter) writes:
< In article <90011904272373@masnet.uucp< jf.messier@canremote.uucp (JF MESSIER) writes:
< 
< <  From: jf.messier@canremote.uucp (JF MESSIER)
< <  Newsgroups: comp.sys.ibm.pc
< <  Date: 15 Jan 90 07:45:00 GMT
< <  Organization: Canada Remote Systems Limited, Mississauga, ON, Canada
< <
< <  <<       Is it possible to use a MFM hard disk drive with an RLL
< <  <<       controller? Are there particular MFM drives that will do it?
< <  <<       How would I tell?
< <  <The basic problem is that the coating on the disk is not designed to
< <  <handle the density of data used by the RLL format, and it WILL
< <  <'forget' what you have stored there.
< <
< <      I had a really bad experience with such controllers. At Revenue 
< <  Canada, we have a lot of Epson Equiti I+, each with a 30M hard disk 
< <  (in fact, a 20M and a RLL controller). BUT, the drives used were 
< <  Miniscribe, NOT APPROVED for RLL, so MFM-ONLY. We had problems, mainly 
< <  new bad sectors appearing and destroying information. ...
< 
< I recently bought a FlashCard-30 from CompuAdd, built from an RLL
< controller and a MiniScribe 8438.  The disk would format properly, but
< a couple of days after being formatted it would start failing the
< PC-TOOLS verify test (new bad sectors, and eventually hard seek
< errors).  I'll be calling CompuAdd this week, but my problem certainly
< seems to be explained by the article above.  Does anyone know if
< in fact the MiniScribes are *NOT* reliable RLL drives, in general?




In contrast to the previous posters' experiences I have been
running two miniscribe 6850 70mb mfm drives with an rll controller
24hrs a day for 7 months now with no problems except that if I power
the system down for some reason and let it get cold (~60F) I get
errors when I reboot - I just let the machie run for ten minutes
and then no more problems once it is warmed up)