Instructions
Insert the disc into your PS3. The device should automatically recognize the disc and start your console.
Boot the GameShark disc by navigating to the "Games" column and pressing the "X" button on the disc. The GameShark menu will load, the same as it would if you were to load it on an original PlayStation.
Press the "X" button on the game to which you would like to add codes. A list of already-listed codes will appear.
Press the "X" button on "Enter New Code" at the top of the menu. An input screen will appear.
Enter the code you want to use and press the "Start" button to save your code. The code will automatically be added to your list of the specified game.