https://www.reddit.com/r/Roms/comments/1007vjm/safe_websites_for_ps2_bios/
Jan 1, 2023 · PCSX2 requires a BIOS to work, the BIOS can be provided as a single 4MB .bin file or with additional files (usually .erom, .nvm, .rom1 and .rom2)." ¹ ps2-0100j-2000