How does Duck Hunt for NES work exactly?

Question

I'm trying to figure out how Duck Hunt knows where you aim when you fire the lightgun. I recall being younger and holding the gun to the tv and shooting the ducks/clay directly and the screen would flash where I shot. How does the game know where you aim?

Answer 1

on wikipedia:

When the trigger was pulled, the game blanked out the screen with a black background for one frame, then, for one additional frame, drew a solid white rectangle around the sprite the user was supposed to be shooting at. The photodiode at the back of the Zapper would detect these changes in intensity and send a signal to the NES to indicate whether it was over a lit pixel or not. A drop followed by a spike in intensity signaled a hit. Multiple sprites were supported by flashing a solid white rectangle around each potential sprite, one per frame.
============


another interesting feature of yahoo answers is that not only can you ask questions, but you can see if someone else asked the same question you did.

in your case, depending on what words you decide to use, at least 45 people have already asked the same question

you can find a good amount of them through this link - http://answers.yahoo.com/search/search_result;_ylt=Ag4Pa2IMhulADdiA0Zxi_lMjzKIX?p=how+Nintendo+Gun

i copy pasted some from - http://answers.yahoo.com/question/index;_ylt=Aj5iImBMNjNmTemePq8_gWYjzKIX?qid=20060703173942AAoFcRs

Answer 2

This is what some techy guy explained to me once - i believe its how it works. As you may or may not know TVs refresh the image on screen at very fast speeds so give the illusion of movement - just like a cartoon. When you pull the trigger the NES sends a unique coloured pixel (or group of pixels) across the screen one row at a time i.e. row one left to right, then row 2 left to right and so on all the way down the screen. Inside the gun is basically a magnifying glass so that its only focusing on a tiny part of the screen. Eventually the pixel will come into the line of site of the Gun and the NES knows then thats where the gun is pointing on the screen. Of course this happens stupidly fast - the NES has got into the line of site before youve released the trigger.

Answer 3

The gun s photosensitive. That flash you see is the screen blinking many times per second/ per second...the targets however are illuminated (square) while the rest of the screen flashes to black. The gun will pick up the white box, if it is in the line of sight --meaning you aimed correctly, you score a hit. if the gun does not read the bright square, you aimed poorly and the duck flies away.

That is as simple as I can get it.