In order to use these cheats, you must first do some file editing. Please keep in mind that this is done at your own risk. Your file/computer can become messed up as a result. Head to your game's Configuration folder and open the file Turokinput.ini as a text file. Once there, you'll see a line that says ConsoleKey=None. Change "None" so that it reads "Tilde" instead, and save your file. This will let the tilde (~) key open up the cheats console. Then, enter the cheats as listed below.
* allammo - Gives you maximum ammo
* allweapons - Unlocks all weapons
* fly - Allows your character to fly
* ghost - Allows your character to pass through objects
* god - God Mode
* loaded - Unlocks all standard weapons
* walk - Deactivation code (for "fly" and "ghost")