After you have written the .cht file, you have to enable the cheats individually in the game menu. Go to the Cheats/Misc menu, and you will see the cheats; turn them on here. You may turn them on and off as you please, but note that some cheats may still hold after you turn them off, due to the nature of the system. Restart to completely get rid of them.
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Not all of gameshark's features are supported, especially for v3. Only basic cheats will work, more or less. Cheats may be unstable and may crash your game. If you're having problems turn the cheats off.
