To emulate legally, you must dump your own PS2 BIOS from a console you own and create ROMs from your physical game discs. Downloading ROMs from random websites is copyright infringement and carries malware risks.
Before diving into the "how-to," it is important to clarify what these terms mean in a modern context: Gameshark Ps2 Rom
The term "Gameshark PS2 ROM" is slowly becoming obsolete. Modern emulation tools have surpassed the original hardware: To emulate legally, you must dump your own
That said, nostalgia keeps the Gameshark alive. The distinctive user interface—blue and yellow menus, the chime sound—is a potent time capsule. For many, running the original Gameshark ROM in an emulator is as much about reliving 2002 as it is about gaining invincibility. That said, nostalgia keeps the Gameshark alive
Solution: Check region codes. A GameShark code for the USA version of Kingdom Hearts will not work on the EU (PAL) ROM. Also, ensure you are using the correct code type (Master codes must be enabled).