: Used by the majority of "Fat" models (SCPH-30000 to 50000) and early "Slim" models (SCPH-70000 series). These are highly stable and widely considered the best for homebrew and general compatibility. v2.3 (Late Slim models)
: This BIOS version is famously known for a critical internal change: it removed the ability to boot Free McBoot (FMCB) from a memory card. Hardware Integration all ps2 bios files including the new scph90006 exclusive
Known as "v1.0" or "proto kernels." Can have glitches in memory card emulation. SCPH-3000x to 5000x : Used by the majority of "Fat" models