| Emulator | Requires BIOS? | Notes | |----------|----------------|-------| | | Not required (HLE BIOS built-in) | Free version works without BIOS; Premium adds save states, high res. | | Flycast (RetroArch / standalone) | Yes (optional but recommended) | Better compatibility with homebrew and some retail games. | | nullDC (obsolete) | Yes | No longer updated; use Flycast instead. | | DEmul | Yes | Requires full BIOS set for Dreamcast, NAOMI, Atomiswave. | | Reicast (old) | Yes | Discontinued; use Flycast. | Rule of thumb: Flycast + real BIOS = highest compatibility. Which BIOS Files Do You Need? The Dreamcast had several BIOS revisions across regions and hardware iterations. For full emulation, collect these MD5 hashes (common names in parentheses):