Subject: MMC/Mt Fuji: Clarification about R and RW/Rewritable profiles
Date: Fri, 13 Oct 2006 22:05:28 -0700
From: David Burg <daviburg@windows.microsoft.com>
To: <t10@t10.org>, <mtfuji5@avc-pioneer.com>
CC: Bhanu Gogineni <bhanu.gogineni@microsoft.com>,
   Ahmed Tolba
	<ahmed.tolba@microsoft.com>
X-Message-Number: 7320
Formatted message: HTML-formatted message

Hello,
During validation of DVD-ROM devices conformance to the MMC command set
through the Windows Vista Logo program and MMCTest tool, we were
signaled the possible flaw in either our tool or the specification. Our
tool query from the drive the list of profiles supported by the drive,
and then exercises each of the profiles. Some ROM drives will also
report R and/or RW profiles. Thus our tool attempts to validate these
profiles, and as part of the validation attempts to validate that the
drive recognize blank media properly.
Yes, blank media. I understand that hardware manufacturers may very well
be reluctant to guarantee this capability on ROM drives. The value of
recognizing blank media in a ROM drive that won't be able to write it is
also questionable. However there are also positives aspects: a ROM drive
able to recognize the blank media will not spin un-definitively in
attempt to find a track, it will further be capable to report that the
media is blank to the host so that the host software may report the
issue to the user and help him to correct his mistake.
Clearly some ROM drives do not support recognizing blank recordable or
rewritable media, even sometimes do not recognize recorded recordable or
rewritable media.
So the question is: Does reporting R and/or RW/Rewritable profile by a
drive mandate that it is capable of recognizing the matching blank R
and/or RW/Rewritable profile?
Best regards,
David Burg,
Microsoft Corporation.