Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!pdn!boake2!jc3b21!larry
From: larry@jc3b21.UUCP (Lawrence F. Strickland)
Newsgroups: comp.sys.ibm.pc
Subject: Re: RLL controllers with MFM drives
Message-ID: <781@jc3b21.UUCP>
Date: 23 Oct 89 14:19:29 GMT
References: <35883@srcsip.UUCP>
Organization: St. Petersburg Jr. College, FL
Lines: 47

From article <35883@srcsip.UUCP>, by rogers@SRC.Honeywell.COM (Brynn Rogers):
> In article <4265@ncsuvx.ncsu.edu> unkydave@shumv1.ncsu.edu (David Bank) writes:
>>   Sure, Ken. Go for it. Hook that MFM (i.e. NOT RLL-Rated) drive up to
>>that RLL controller, format it, and instant 50% more drive room. You
>>CAN do it. It'll even format.
> 
>>   If you're lucky, it might even hold data for a month before it starts
>>developing amnesia.
> 
> I think that this is a little overboard. (or Dave sells drives)
> 
>    One Manufacturer in particular (Maxtor) does not rate many of it's drives
> RLL and yet I have had one running for over a month at almost double its 
...
> Some MFM drives will work RLL, some won't. About the only way to be sure
> is to try it (But keep everthing backed up, and keep your MFM controller)


This particular question seems to pop up over and over again, but there are
rarely any real solutions to it.  Much of the problem seems to be related to
the drives used, not whether MFM drives will work as RLL in general.

Yes, the RLL encoding scheme is more intensive on the disk.  Yes, formatting
an MFM drive as RLL may or may not work.  About that question of it working
for a month or so and forgetting, well...

I thought for a considerable period of time before attempting to reformat
my 72 Meg Miniscribe drive as RLL.  However, the 70 Megs was too small for my
application and I really didn't have the money to upgrade to a bigger drive and
several people said they didn't _think_ there would be any problem, so I went
ahead and reformatted.

It has been running for most of a year now with no data loss.  The controller
card I used was the Adaptec which has been beaten up on the net but which has
worked well and, because of its on-board ROM, has allowed me to use both XENIX
and DOS together on the same drive.

My experience has been very positive and I recommend the Miniscribe line for
other reasons as well.  So, if you have a Miniscribe, it seems likely that it
will work (at least the full-height 72 Meg drive :-)

-l
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