C/P from ABGX
"One of the ways Microsoft can detect you being a dirty, filthy pirate is to scan this video to make sure it matches with what is supposed to be on the disk, so to protect you, the firmware itself does a quick checksum of it and if it doesn't match with known video data, it wont boot. Every now and then, this video changed, with each change being called a "wave"."
End of C/P
If M$ can "check" the video partition for validity, why the hell not can't they detect what firmware is on any DVD drive? All M$ has to do is check the "checksums" on any given line of the code (firmware). Running modified firmware would generate a different checksum for the modified areas in the firmware. All they need to do is look at one checksum value - stock firmware has one value while modified ones will have a different value. All it takes is one line of code in the firmware changed, and that line will have a different checksum.
When you turn on a 360, it runs through a self dignostic check. It would be very simple to write 360 firmware (dashboard code) that checks the DVD rom when you turn on the 360. Currently our 360 checks the DVD drive during bootup. This would be the best time to check DVD rom firmware.
With all the bans over the years, and nobody has even the slightest clue what M$ is detecting to trigger a ban. I believe it's as simple as the 360 checking certain sectors (blocks) of the DVD rom f/w. With all the xbox360 can do (speed, graphics, etc), are you gonna tell me that they can't check firmware on the DVD rom drive? M$ has complete control over the DVD rom drive, they have to - otherwise nothing would boot PERIOD.