For gamers who grew up during the NES and Master System era, light guns were probably commonplace in the home, but have you ever wondered how they worked? Well, the Zapper and Light Phaser guns work by receiving light through a photodiode on (or inside) the barrel and then using that light to calculate where you’re aiming at on the television screen. After pulling the trigger, the NES blacks out the screen, and the Zapper diode begins reception. The computer flashes a solid white block around the targets you’re supposed to be shooting at, and the diode’s reception of light (changes in intensity), combined with the sequence of the drawing of the targets, lets the computer know that you hit a target and which one it was. You don’t notice this while playing because it happens in a fraction of a second. Continue reading for more.