Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!microsoft!brianw
From: brianw@microsoft.UUCP (Brian WILLOUGHBY)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Drilling holes in DS/DD -> DS/HD
Message-ID: <10043@microsoft.UUCP>
Date: 22 Dec 89 02:15:04 GMT
References: <16918215MES@MSU> <5912@mentor.cc.purdue.edu>
Reply-To: brianw@microsoft.UUCP (Brian Willoughby)
Followup-To: comp.sys.mac.hardware
Organization: Microsoft Corp., Redmond WA
Lines: 24

ar4@mentor.cc.purdue.edu (Piper Keairnes) writes:
>The people using the 800k disks buy them from MEI Micro and have found that
>the disks that won't format to 1.4 meg will also not format at any other level.
>That is, if the disk is good to begin with, it will work at all formats. Now,
>I have bought about 100 disks from MEI Micro and have not had one failure. Must
>be my clean environment or maybe they had drive problems to begin with.

I understand that the high density pattern placed on an HD disk interferes with
subsequent attempts to re-format at a lower density.  Wouldn't you need to wipe
the old formatting off (with an electromagnet, perhaps) before assuming that
the disk REALLY can't be formatted at 800K either?

On another note, our Compaqs don't appear to check the HD hole before
formatting, anyway.  So I started out using DD disks at 1.44M HD format.  The
problem is that I was making backups, and when I finally returned to examine
the data on these over-formatted disks, there were a few sector failures.  Not
many, but you only need to lose one sector in the FAT or Root directory before
you pay the price for skimping on disk costs.

Brian Willoughby
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