Not sure if there is a Dreamcast the Xbox but the DC can be run using a boot disc and backups can then be played. If you don't have a DC then I bet you could get a cheap one on fleabay.
i seem to remember the chankast was being ported at one point,but was getting shitty framerates so it was canned,as spikeman says dc is cheap and you dont even need the boot disc for the majority of games