Dear Quinn, That was an especially encouraging note with lots of good info and a really good suggestion. Unfortunately, I have yet to overcome the basic hurdle of getting my KEXT to be active in the IORegistry stack without sustaining a reboot. The object I am over-riding is 'IOSCSIPeripheralDeviceType05' which is contained in the 'IOSCSIMultimediaCommandsDevice' family bundle. By putting the kext in the /System/Library/Extensions folder and then performing an 'open() - read() - close()' sequence for the BSD path of "/dev/rdisk4' - which was the CD-ROM of interest in this case - I found (via kextstat and ioreg commands) that the kext did not get loaded into the place where it appears if one reboots the computer. Do you have any other ideas or paths that seem like something I might pursue? In any event, thanks very much for your input. Best Regards, Lance Drake _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.