Mailing Lists: Apple Mailing Lists
Image of Mac OS face in stamp
 
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Identifying CD drives across reboots

Stephen F. Booth wrote:
I need to identify the drive in order to determine (and store) the drive's read offset. To preempt your next question: I need to do this to accurately access CDDA in a device-independent manner. :)
Consider spinning up the media in the drive and ask for the media ISRC, or whatever media-level identification is present on the particular flavor of CD you're working with. Compare this against the expected and known values in your database, and jump to the right sector.

Remember that drives won't get insulted if the application chats using a command subset, but the drives do throw a snit if they don't understand what the application has asked, or don't offer the particular command or feature. Worse, some drives can and do become catatonic when they get confused, and some become solidly confused quite easily.

I'd not bother looking for a unique drive serial number or trying to aggregate and synthesize such based on model and vendor. What happens if you're dealing with a tower of identical drives, for instance? The ISRC is probably your best bet here, based on your stated goal.

Do you have access to the Red, Yellow and Orange books? These and the T10 and T13 documents are soon to be your friends. (And for anyone just getting their tootsies wet in this area, find and start with the INF-8020/SFF-8020 document. 8020 is long retired and long superseded, but it's one of the few good classic introductions to CD operations around.) Drives also tend to be creative about the parts of and the revisions of T10 and T13 implemented.

_______________________________________________
Do not post admin requests to the list. They will be ignored.
Darwin-dev mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/darwin-dev/email@hidden

This email sent to email@hidden
References: 
 >Re: Identifying CD drives across reboots (From: "Stephen F. Booth" <email@hidden>)



Visit the Apple Store online or at retail locations.
1-800-MY-APPLE

Contact Apple | Terms of Use | Privacy Policy

Copyright © 2007 Apple Inc. All rights reserved.