The story of the is not just a story about a computer chip; it is the final chapter of one of the greatest eras in gaming history. It represents the moment Sony killed the emulator, perfected the hardware, and bid farewell to the console that defined the 2000s.
The SCPH-90001 revision introduced a major motherboard redesign (codenamed ):
The BIOS is the core software that initializes the PS2 hardware and allows emulators like PCSX2 to function on a PC. For the SCPH-90001, the BIOS version is typically (or sometimes v2.20 in very early launch units).
Sony had finally patched the "Datecode" exploits that allowed users to install custom firmware via a memory card. For a long time, the SCPH-90001 was considered "unhackable" via software. It was the ultimate cat-and-mouse game. Sony had won the BIOS war right at the very end. If you wanted homebrew on a 90001, you had to physically modify the console with a modchip, a risky and difficult process compared to the easy software hacks of the past.
Below is an article covering the technical importance of its BIOS, how it differs from earlier models, and the legalities of using it for emulation.
The PS2 BIOS ROM (usually 4 MB) includes: