Begin by reaching the menu where you can opt to enter Cyberspace or the Arena. Head to the Options menu and opt to change your name. Do so and change it to "CONFIG_SYS", without the quotes. Press Start and you'll reach a debug menu where you can choose any of the 75 levels to start on, your armor, Auto-Mag count, speed, lives, and rate. Press Start and you'll then start the game under the conditions chosen.