I’m just going to keep guessing; it’s much easier than digging up actual, empirical data. I’m starting to come to grips with the idea that the number of valid sectors contained on a DVD disc is something that’s interpreted by the optical drive firmware and enforced by the same (as is the case for RPC-2 DVD region encoding). If that’s true, there is no point in using direct SCSI access to beg for sectors beyond the magic 6,992 limit on a standard Xbox disc. Ways around this? There’s the Xbox-Linux FTP trick alluded to in my cursory post on the matter…
But it could be that it’s the firmware in the Xbox’s optical drive can properly interpret an Xbox DVD’s header structure. If that’s true, then it should be possible to take the DVD-ROM drive out of Xbox (since the drive is just an ATAPI device), hook it up to a computer, and start reading away. Used Xboxes start at $125 on Amazon.com. On a whim, I searched for “broken xbox” on eBay and met with quite a few results. Most of the merchandise consists of boxes that emit some error code on boot up. These problems are solvable with a Google search and the broken units are hotly contested auctions that sell for well under the usual used price. There’s another route– there are replacement drives available from Samsung, Philips, and Thomson. These units go for $30-$60. However, careful inspection of some drive pictures reveals that they do not use the standard Molex power connector that one would typically expect from an optical drive. The space for the power connector is closer to that of a 3.5″ floppy drive power connector. Some image searches reveal that this adaptor is probably proprietary, which makes sense– if you’re going to make anything about this proprietary, the power cable is probably the easiest and cheapest thing to modify.
In other news, I stopped at a video game shop last night to see if enough time has elapsed that I could pick up a used Xbox 360 game — probably a stale sports title — for reasonably cheap (remember that new Xbox 360 titles normally go for $60). Sure enough, there were used copies of Madden NFL 06 for $12 (the store receipt helpfully noted that I saved $18 buying used). It seems that, when played as DVD video, these have an even shorter intro video before showing the above message is displayed in more languages than I can even name. Only 3,519 sectors are used on this disc. It is apparently possible to get replacement optical drives for the Xbox 360, but in the neighborhood of $80. These have SATA interfaces. However, according to some pictures on AnandTech, it looks like the drive has something other than the usual SATA power connector.
Oh, and I also tried the direct SCSI access trick with a GameCube title. No dice. But I think I’m starting to understand a little more about how these discs operate, or at least I’m formulating some plausible-sounding theories.