Cheat codes in video games used to be rare. Now they're a given. Push a magical combination of buttons and you'll advance to a hidden level. Or press the right sequence to execute undefeatable fighting moves. But the cheat codes for the Atari 2600 were different. Sometimes they were a way to defeat a seemingly unbeatable arcade game. Other times, they were nothing more than hidden graffiti-signatures left by programmers who had to fight to get even the slightest bit of recognition for their work. Here is a sampling of some of the more memorable hidden codes in Atari's library of classic games.

		Breakout To play with an unlimited number of balls, play one of the catch games. On the last ball, press "select" to catch the ball, then release it. You will switch to a demo mode where you can't tally points, but you can play with an unlimited reserve of balls.
		Dig Dug If you allow a few rocks to fall before you chase your enemies, vegetables will eventually appear in the center of the screen. Scoop up those vegetables for extra points.
		Galaga Destroy all the ships except for the two in the lower left corner of the formation. Avoid the ships as they dive and fire at you until they no longer fire. The enemy will not shoot at you for the rest of the game.
		Galaxian Hold reset when you turn on the game for quicker shooting.
		Missile Command If you fire three missiles at the top of the screen when the game starts and press reset before the missiles explode, you will score extra points when they do explode. Also, if you fire all of your missiles without scoring points and let the incoming missiles destroy your cities, the city on the right will turn into an "RF," the initials of Rob Fulop, the Atari employee who converted the arcade game.
		Pac-Man Eat one ghost on maze 1, two ghosts on maze 2, three ghosts on maze 3 and finally, four ghosts on maze 4. Move the controller up, down, up, then intentionally lose a life. You will have unlimited lives in the game. Also, when you enter the tunnel, quickly move the controller up and down several times, making down your last move. Pac Man should be able to move up and down through walls of the maze when he emerges from the tunnel.
		Raiders of the Lost Ark If you take the Chai and a parachute to the flying saucer area, leap off the mesa and drop the Chai, Yar from Yar's Revenge will appear. Subsequently, if you score the high score, the initials "HSW2" will appear, which belong to Howard Scott Warshaw. The 2 signifies that it was the second game he designed for Atari.
		Robotron 2084 On the tank level, try to avoid the tank fire. They can fire themselves out, making them easy to pick off.
		Space Invaders Hold down the reset button while powering up the game. When you select "game one," you will receive a double shooter.
		Chess In games 6 and 7, the CPU will move pieces as it calculates its next move.
		Combat Hold reset and fire to shoot toward the other side of the screen.
		Decathlon To vault higher on the pole vault, continually press fire as the pole is released.
		Defender On wave 25, collect a humanoid and then position your ship where it begins each wave. The remaining enemies on the screen will change to "BP," the initials of Bob Polaro, the programmer who converted the game for Atari.
		Pete Rose Baseball Hold the fire button down as your team leaves the field to bat. The opposing pitcher will automatically throw a strike on the first pitch.