Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!cbmvax!brim
From: brim@cbmvax.commodore.com (Mike Brim - Product Assurance)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Can you RLL format the Seagate ST251 drive?
Message-ID: <14309@cbmvax.commodore.com>
Date: 10 Sep 90 12:23:28 GMT
References: <4285@trantor.harris-atd.com>
Reply-To: brim@cbmvax.commodore.com (Mike Brim - Product Assurance)
Distribution: na
Organization: Commodore, West Chester, PA
Lines: 32

In article <4285@trantor.harris-atd.com> sonny@trantor.harris-atd.com (Bob Davis) writes:
> 
> 	Have you ever RLL formatted an ST251 42Mb MFM drive? Can you
> get it to go 63Mb that way? I have an Adaptec 2372 RLL controller. If RLL
> is possible, then by the DEBUG g=c800:5 jazz, do I declare 820 cylinders
> and 6 heads? What are the details of what I must do to try RLL formatting?

I've been running a ST251 on an Adaptec 2372 for about 2 years with no problem.
You only have to declare the 820 cylinders and 6 heads.  The only problem you
may have are defects.  You cannot enter the ones on the defect list and expect
them to be marked correctly.  Since the Adaptec does a nice low level with 
verify this MAY not be a problem.  I would also run Spin Rite II on it.  Before 
using the drive, test it out.  Run any type of hard drive banging program you 
can find.  At least make a batch file to copy files and compare them.  Run it
for a few days non-stop.
> 
> 	Does the 50% increase in drive capacity under RLL formatting
> compared to MFM *always* come because there are 26 sectors/track for RLL, 
> and only 17 sectors/track for MFM? And therefore does one always use
> the SAME number of cylinders and heads for RLL as for MFM?
> 

If I understand your question correctly, The only (high level at least) diff.
between RLL and MFM is the 26 vs. 17 sectors.  
-- 
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Disclaimer: My company knows not what I say (or do).

Mike Brim			     |	Commodore Electronics Limited
PC Analyst - System Evaluation Group | 	West Chester, PA 19380
Product Assurance		     |	InterNet: brim@cbmvax.commodore.com
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