Simpson474 has ported the Nintendo 64 emulator DaedalusPSP to the Dreamcast. It sounds very exciting, but the emulator is very slow which does not make it useable for playing any games. Read the details over at DCemu – there is also a video available along with the downloads.
http://dcemu.co.uk/daedalusdc-released-n64-emulator-for-the-dreamcast-2-versions--83587.html