The term stands for Basic Input/Output System. In the context of the PlayStation 2 console, the BIOS is a small chip embedded in the motherboard that contains the essential firmware required to boot the system. It initializes the hardware, loads the operating system, and manages the security checks that verify a legitimate game disc has been inserted.
Use BIOS v2.20 (USA or Japan) for PCSX2 1.7.0. Earlier versions (1.10) lack DVD player code, causing crashes in games that call rom0:OSDSYS during video playback. pcsx2 1.7.0 bios