Many users chase the latest BIOS (e.g., from a SCPH-90000 slim) believing it works with “more games.” However, experienced emulation veterans know that newer BIOS versions sometimes introduce that break:
Because it is the oldest and most basic revision, the SCPH-10000 BIOS is known to be missing some software libraries (or "libaries" as they are often misspelled in forums) that many games require to load properly. The PCSX2 community has long recommended avoiding this BIOS for maximum compatibility, citing potential problems with memory card emulation and overall stability. sony playstation 2 bios file name scph10000zip top