With the introduction of the latest and greatest video game systems being introduced, I took notice of the new Nintendo "Wii" system. What makes this different is that you use the motion-sensing controller and physically make the movements that you are trying to do in the game. For example, if you are playing a Baseball video game, instead of pushing a button to swing the bat, you would actually stand up swing the "Wii" controller itself. While I am not a big video gamer at all, nor do I even own a system, I really liked this idea. If not anything else, I requires children (and adults too, I suppose) to get up and move their bodies instead of just sitting on the couch.
However, seeing this system in action reminded me of a somewhat similar interactive video game system of my childhood, the Nintendo "Duck Hunt gun." As a child, my cousin and I would sit for hours aiming the gun at the television screen, lining the flying ducks in the sights, and then firing the trigger, shooting the ducks dead. At the time, the game was very fun in a simple sort of way. As a child, I never gave it much thought how it worked... I just thought that the TV was somehow receiving a signal from the gun, and registering where on the screen it received it, and then either registered a hit and miss. However, I was was watching the commercial for the new "Wii" system, it hit me... there is no way a TV can receive anything through the screen. So, how they heck did the 'Duck Hunt gun" work? How does the game know where the gun in aiming on the TV screen?
My research tells me that the gun actually worked the exact opposite of that of my childhood understanding. Stripped of the high-tech accoutrements (by 1980s standards, anyway), it's the oldest trick in the book. You think you're using the gun to shoot at the TV, right? But really the TV is shooting the gun.
Here's what happens. You shoot at a duck, which appears on an ordinary TV screen. The gun is connected to the game console; pressing the trigger blackens the screen, then causes a duck-shaped white target to appear momentarily. If your aim is true, a photo sensor in the gun detects the shift from dark to light, and bingo--dead duck. In short, the TV emits the light pulse and the gun detects it, not the other way around.
For technical details, see www.howstuffworks.com/question273. htm, which includes a link to Nintendo's 1989 patent on the technology. The patent explains how the dark-to-light shift prevents you from cheating by pointing the gun at a steadily shining light source, a weakness of earlier light guns. You'll also learn how multiple targets can appear on the screen at the same time and how more advanced systems can indicate on the screen exactly where your shot "hit."
Take that, "Wii."
