Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!cs.dal.ca!ug.cs.dal.ca!walker
From: walker@ug.cs.dal.ca (Paul D. Walker)
Newsgroups: comp.sys.ibm.pc
Subject: Help needed for MFM drive with RLL controller
Keywords: can ST251 be used as RLL?
Message-ID: <1989Nov29.074452.9386@ug.cs.dal.ca>
Date: 29 Nov 89 07:44:52 GMT
Reply-To: walker@ug.cs.dal.ca (Paul D. Walker)
Organization: Math, Stats & CS, Dalhousie University, Halifax, NS, Canada
Lines: 48


     Recently, there was a lot of discussion in this news group of formatting 
an MFM drive to RLL capacity using an RLL controller.  From my understanding
of the resultant debate was that it was safe to format (in general) the MFM as
RLL, and that with the higher quality drives and drive controllers, that this 
would not be a problem with the hardware.

	My question is, can a Segate-251 MFM drive be used as an RLL drive?  For
those that don't know, the ST-251 is a 28ms access, 40 meg hard drive with 
820 cylinders and 6 heads (type 40).

	The RLL card that I am trying to use with this drive is a Data Technology
Corporation (DTC) 7287 RLL Controller card.  

	I have tried using the cards on board firmware to format the drive 26
sectors per track instead of 17.  If I used the standard types table, it is 
also a type 40 drive.  After the type has been set, my machine is rebooted 
and the low level format program is run.  Immediately, an error is returned
and nothing happens.  It seems that the drive does not like any of the 
commands that the controller sends to it.

	I tried to use a program called 'Speedstore which is a 'hard disk
preparation and maintenance program'.  For a drive type, I tried changing the
number of sectors from 17 to 26.  When this program tries to format the disk, 
it comes back with a '01h bad command to bios' message, and then stops.

	I also tried to select the ST-277R type (820 cyl, 6 heads, 26 sectors) and
received the same error message.

	Can anyone tell me if the drive can be used as RLL or not?  Is the ST251's
bios limiting the us of the drive to MFM only?  Does anyone know how to make
this work together?  Any help or pointers would be greatly appreciated.

	Oh, there is no need to tell me that Seagate will not honor the warranty
of on of their MFM drives used as RLL.  I am aware of this, and the warranty 
has expired anyway.

Thanks in advance for any help that anyone can give me.

- Paul D. Walker                 -       _   /|            - Dalhousie U. 
 - walker @ dalcsug               -      \'o.O'    Ackpth!  - Comp Science
  - walker @ ug.cs.dal.ca          -     =(___)=  /_Thptpth! - fourth year! 
   - {utai | uunet}!dalcs!ug!walker -       U                 - Gonna graduate 
    - 01WALKER @ DALAC.BITNET        - Bill for President!     - soon...