Most 8-bit and 16-bit consoles (NES, SNES, Genesis) work without BIOS files. However, the following systems files to function legally and correctly:
Batocera.linux is a free, open-source operating system designed for retrogaming and emulation. A "Batocera ISO" typically refers to a disk image of Batocera packaged in ISO format for burning to optical media or for creating bootable USB/DVD installs. More commonly, Batocera is distributed as compressed archives (ZIP) or as raw disk images (.img) for flashing to SD cards/USB drives; ISO builds exist primarily for ISO/legacy-boot scenarios or custom builds. batocera iso
For devices like the Odroid N2+ or Rock Pi 4. These are powerful ARM SBCs. Most 8-bit and 16-bit consoles (NES, SNES, Genesis)