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From: david@kessner.denver.co.us (David Kessner)
Newsgroups: comp.sys.ibm.pc.hardware,comp.multimedia,comp.misc,connect.audit
Subject: Re: Diffs between DD & HD disks
Message-ID: <1991Apr10.075541.638@kessner.denver.co.us>
Date: 10 Apr 91 07:55:41 GMT
References: <1991Apr9.075828.2135@ibmpcug.co.uk>
Organization: Kessner, Inc.
Lines: 29

In article <1991Apr9.075828.2135@ibmpcug.co.uk> hdrw@ibmpcug.co.uk (Howard Winter) writes:
>BTW I understand the medium used in DD vs HD disks IS different,
>and that the coercivity (the ease with which magnetism becomes
>permanent) is the variable.  I have certainly never been able to
>reformat an HD 3.5" to 1.44 once it has been formatted at 720,
>and I believe that the switching of strength of magnetism used
>is the reason  -  the weaker HD field cannot overcome the 720.
>
>But I may be wrong...
>
>Howard.

The HD disks are different from the DD disks...  I dont know why this is really
a question.  I mean, just look at them!  HD disks are darker and more highly
"polished".  DD disks are rather dull...

I have always had a problem reformatting disks at a different density, I 
dont know why.  Using a big magnet or a bulk eraser will fix the problem,
however...

I for one will never use disks beyond their rating (ie, using DD as HD, or
SS as DS).  While it may work for the most part, you do get more errors
than normal-- perhapse only one critical error every 10-20 disks but you never
know WHEN that error will pop up.  I'd rather have some piece of mind, rather
than play Russian Roulette...
-- 
David Kessner - david@kessner.denver.co.us            | do {
1135 Fairfax, Denver CO  80220  (303) 377-1801 (p.m.) |    . . .
If you cant flame MS-DOS, who can you flame?          |    } while( jones);