It looks like backup copies of games can now be booted on the Xbox 360. Maxconsole has the video. This hack is similar to the final firmware hack of the original Xbox. The response to the challenge code is written directly in the firmware. So instead of checking the disc, the firmware responds to the challenge directly. Here are the technical details. This hack doesn’t allow you to run unsigned code or ignore region codes. All it lets you do is play direct one-to-one copies of game discs.