The only (and strictly legal) way to obtain this file is through a process called "bios dumping." You take a physical SCPH-70012 console, use a homebrew tool like BIOS Dump Utility run via Free MCBoot, and copy the ROM to a USB drive.
The BIOS file originates from one of the earliest "Slimline" PS2 revisions. Key characteristics of this hardware include: Integrated Modem SCPH-70012 is one of the few slim models to include a built-in 56k modem port alongside the standard Ethernet port. Chipset Architecture : Contains the original MIPS-based PS1 CPU scph-70012-bios-v12-usa-200.bin