Hi,
this is cut from wikipedia:
Contrary to popular belief, all Dreamcasts recognize and play CD-R's, however, Mil-CD support was removed from later revisions of the Dreamcast hardware. The manufacturing and distribution of these revisions were extremely limited, none being shipped and sold by Sega outside of Japan, with the first and one of the few models of the revised Dreamcasts being the limited Sakura Taisen model.
Just imported a DC from the US. After placing the order I found this thread.
When I recived the DC I discovered that it was labeled '2'.
I tried booting with a cdr and that failed. But these were just some cheap cdr i had laying around.
According to the wikipedia my DC should be able to boot backup games so I'm not giving up just yet
I will keep you posted, if I am able to get this to work.