Under copyright law, the BIOS is proprietary Sony firmware. The only legal way to obtain this file is to:
Because this is a Japanese BIOS, the system configuration menu (the "Internal Browser") will be in Japanese. Most games will still play in their native language (English, etc.), but the system clock and memory card management screens will reflect the BIOS region. Conclusion Scph10000.bin Ps2 Bios
Downloading the file from a random ROM site is piracy, plain and simple. Emulation isn't illegal; downloading copyrighted BIOS files without owning the original hardware is. Under copyright law, the BIOS is proprietary Sony firmware
When looking for a "complete" BIOS set for emulation, the scph10000.bin is often accompanied by: Extended Read-Only Memory. ROM1.bin: Additional system data. Under copyright law