Redream uses a high-level emulation (HLE) BIOS reimplementation. This is less accurate. Flycast uses low-level emulation (LLE) and demands the real BIOS. Stick with Flycast for compatibility.

Here is exactly how to fix the missing Dreamcast BIOS error and get your library running in Flycast. 1. Identify the Correct BIOS Files

: Make sure your EmuDeck is up to date. Sometimes, updates fix known issues or improve compatibility with certain games or BIOS versions.

On your Steam Deck’s desktop mode, open Dolphin (the file explorer). Navigate to: Emulation/bios/

For Dreamcast, you generally have two options for placement within that bios folder: