This indicates the region. BIOS files are region-locked, meaning a USA BIOS is required to play North American NTSC-U games natively.
However, the preservation argument is strong. The SCPH-90001 consoles are dying. Their capacitors leak, lasers fail. Dumping one’s own BIOS using a legitimate tool (like PSX_Dumper or a Teensy 4.0 with a SOIC8 clip) is legal under "fair use" for backup and emulation purposes in many countries (DMCA exemptions for abandoned platforms allow this, though consult local laws). scph90001biosv18usa230rom0 top
The string SCPH-90001 BIOS v1.8 USA 230 ROM0 refers to the system firmware for the final "Slim" revision of the PlayStation 2 (PS2). This indicates the region