How the pistol works in the Dandy console

"Don't shoot the screen, or you'll ruin the TV!" - remember this phrase from our parents? They were sure that Dandy's pistol was shooting with light or an invisible laser. This is a fundamentally wrong statement. Then how does it work and how are target hits recorded in the game? Let's figure it out.

To begin with, this pistol in the west is called the Zapper. So, the Zapper has a photocell that receives light. Thanks to the design of the pistol, the photocell was only able to capture a narrowly focused beam of light. Thus, we come to the conclusion that Dandy's pistol does not shoot light, but, on the contrary, accepts it.

But how is the hit recorded? Back in the 90s, the author of these lines, playing in "Duck Hunt", noticed that at the moment of a shot the entire screen turned black for a split second. So, in this blackness lies the answer to the question. At the moment of pressing the trigger, the entire screen for a split second (one frame) becomes absolutely black. In the next fraction of a second (second frame), a white rectangle is displayed on the black screen in the place where the target was. It all lasts 1/25 of a second. The human eye is unable to capture the transition from a completely black image to an image with a white rectangle. But this can be done by our photocell in the pistol. If at the moment of pressing the trigger you pointed exactly to the target, then the photocell fixes the transition from black to white at the target location. The defeat of the target is counted. If you were not accurate and did not hit the target, then the photocell does not see the transition from white to black, but sees only 2 frames with black. A miss was recorded.

In the case of multiple targets, in a nutshell, hit detection occurs as follows. At the moment of the shot, the screen, again, completely blackens, and in the next frame, only one of the targets is illuminated, through the frame - the second target, and so on. The photocell registers the transition from black to white, as well as the time after how many frames this transition took place. The target itself is determined based on the transition time.

It so happens that many gamers after a decade find their attachment with a pistol safe and sound and decide to "shake up the old days." They hook it up to a brand new LCD TV, turn on "Duck Hunt" and start shooting. They just can't kill a single duck. At first it seems to you that you are just smearing, but after 5 minutes, holding the gun to the TV, you realize that you cannot hit the target even from a distance of 1-2 mm. In this case, the sound of a shot is heard. "Apparently the photocell has broken" - you decide and you decide to throw out the Zapper. But don't rush to the conclusion! The gun might be all right. The problem lies in the LCD TV, or rather, in the delay that occurs when processing an analog image into a digital one. Yes, yes, in LCD TVs we have a small and insignificant latency. And again, our eye is not able to notice it, but the prefix is ​​capable. At the moment of your shot, the screen does not darken, and the above-described output of the white rectangle also occurs with a delay. At the moment when the photocell is triggered by a transition from black to white, there is no trace of this transition on the TV screen. This is precisely why you cannot hit the target. Alas, LCD TVs are not suitable for Dandy's games with a light gun. True, in rare cases, there are still exceptions.