Originally Posted by Mark Fontana
My suspicion is that the entire xfs video data partition on each disk is encrypted using the unit serial number, drive serial number, and probably some shared secret. This would certainly prevent drives from being moved between units as well as prevent drives from being replaced by end users.
It was a while ago, but I did manage to get a second drive to show up in the system menu of my HDD250 by hotplugging the drive (!) after the unit was already up. (It would not boot with the drive connected.) If someone gutsy feels like picking up on those tests, you might try reproducing that result and then doing a disk format from the service menu while the drive is shown. (So basically take advantage of the unit's own ability to prep a drive.) This experiment is above my risk threshold for now.
Are the drives set up as master slave, and in the HDD500 are there files beside the encrypted video (ie the sony files) on the second drive? You're probably correct on the generation of the CPRM ID. The orignal spec came from IBM. Here's an excerpt from a presentation.
"The proposal makes use of around a megabyte of read-only storage on each hard drive that isn't usually accessed by the end user for a "Media Key Block".
According to research scientist Jeffrey Lotspiech of IBM's Almaden Research Lab,
this is a matrix of 16 columns and some 3000 rows. A static "Media Unique Key" in
a separate, hidden area of the drive, identifies the individual drive. "
"Recall that there are two areas that CPRM can be said to
reside - and here, use page 10 of the presentation above. The Media
Key Block (which is most of that megabyte) is in a read-only area, and
the Media Unique Key (which uniquely identifies the disk) is in a
"hidden area". Both are what is called "vendor space" - the part that
handles out of bounds sector"