This message is from the T13 list server.
Larry
I may not be understanding your issue, but I think I disagree with
you. ATA/ATAPI-7 does provide a clean mechanism for indicating the sector
size on the media and the sector size that the host is to use. This also
provides the necessary information on alignment. I am advocating that the
host continue to use 512 byte sectors and that the drive provide the
alignment information to the host when it has a larger physical sector. I
have a white paper on the subject that is ready for public consumption if
you are interested. It documents what is placed in IDENTIFY DEVICE, and
some of the issues associated with going to a larger sector size.
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Curtis E. Stevens
20511 Lake Forest Drive #C-214D
Lake Forest, California 92630
Phone: 949-672-7933
Cell: 949-307-5050
E-Mail: [EMAIL PROTECTED]
Ambition is a poor excuse for not having enough sense to be lazy.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Larry
Barras
Sent: Wednesday, March 30, 2005 5:32 PM
To: [email protected]
Subject: [t13] Larger sector size foibles
This message is from the T13 list server.
I've been made aware of an interesting wrinkle with regard to hard
disk drives which have native sector sizes greater than 512 bytes.
The problem is that someone is proposing to implement the sectors in
such a manner that asking for a 1024 bytes at block 0 actually causes
a mis-aligned operation. To compound the issue, the drive has no
means of indicating whether it is an "odd" drive or an "even" drive.
I propose that all ambiguity be eliminated and that it be prohibited
to implement a drive in such a manner that the natural blocks be
formatted in such a way that a read or write operation in the natural
size of the sectors at any natural multiple of the natural sector
size from block zero ALWAYS be in alignment with the physical
implementation of the drive. So-called "odd alignments" should be
prohibited.
--
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I make stuff go.
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Larry Barras
Apple Computer Inc.
1 Infinite Loop
MS: 306-2TC
Cupertino, CA 95014
(408) 974-3220
