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.