is the BIOS version it carries. Early 9000x models (often marked with date code ) still utilized BIOS versions like v2.20 , which were compatible with traditional softmodding.
You can use a tool like "BIOS Dumper" on a chipped or hacked PS2 to copy your 90006's firmware onto a USB drive. scph90006+bios+new
Open your PCSX2 installation directory and find the bios folder. is the BIOS version it carries