If the emulator runs from a CD you may be out of luck. CDs will only work with MIL-CD compatible Dreamcasts manufactured before October, 2000. Check the date on the bottom of you Dreamcast to see when it was manufactured. I know this because some of the later versions of the Dreamcast wouldn’t run the Bleem! for Dreamcast which allowed you to play certain Playstation 1 games (Gran Turismo 2, Tekken 3, and Metal Gear Solid) on a Dreamcast. My Dreamcast was manufactured on August, 1999.
Are you sure? I thougth that was a myth they debunked some time ago. It may matter for Bleem!, but as for other CDs I thought any DC was capable of running them.