This "swap trick" made the Gameshark a piece of physical hardware and software combined. Over time, updated versions (Gameshark 2, Gameshark 2 Version 2) improved code storage and compatibility.
If you want to experience Gameshark functionality without original hardware, is the gold-standard PS2 emulator. Here is the step-by-step process. Gameshark Ps2 Rom
You would need:
Instead of a GameShark ROM, many users prefer the Cheat Device homebrew. You can download the .ELF file from GitHub, copy it to a USB drive or memory card, and launch it to enable cheats for games loaded via Open PS2 Loader (OPL). This "swap trick" made the Gameshark a piece