Actions
Forum Thread Details
  • Replies 16 replies
  • Subscribers 37 subscribers
  • Views 10195 views
  • Users 0 members are here
Related

An NES Zapper for modern LCD TVs?

Former Member

This is a post i made previously on another thread, but i'm now posting it as its own discussion to hopefully get some response from Ben or anyone else who can figure out how to do this build.

 

Dear Ben (or anyone else with the technical skill to solve this problem),

 

For a while now I've been looking for a way to modify an NES Zapper to work on modern televisions. After a lot of research, i think i have figured out exactly why it doesn't work. Unfortunately, however, i am just a computer science student with only very basic experience in working with electronics, so i do not know how to even begin implementing a solution. I was hoping you would be able to help.

 

As you probably know, the Zapper works by having the entire screen go black save for the targets, at which point a photo diode senses whether or not it is pointing into the light. However, this is actually accomplished by a multistage process which i will outline below:

 

1) The NES redraws the screen completely black for one frame. The Zapper checks to make sure no light is detected before proceeding, preventing any accidental readings from other light sources (this is why pointing it at a light bulb doesn't work).

2) The NES redraws the screen with only target #1 illuminated for one frame. The Zapper checks for light, and the Nintendo determines if the player has hit target #1.

3) The NES redraws the screen with only target #2 illuminated for one frame. The Zapper checks for light, and the Nintendo determines if the player has hit target #2.

4) This process repeats for all targets on screen.

 

The obvious issue with modern televisions is that they tend to upscale the image, resulting in a slight delay that messes up the precise timing required for this sequence to work. Another potential issue i have read about is the nature of the photo diode itself. I have heard that Nintendo opted to use cheap photo diodes that only detect the infrared light coming from the CRT, thus preventing it from working on modern televisions, however i can not verify this.

 

I was hoping that you would be able to come up with a creative solution to this problem that even someone as inexperienced as me would be able to follow (maybe even make an episode out of it ).

 

-Andrew

 

Sources:

https://www.youtube.com/watch?v=c3tBk-LYyzo

nes monitor - Why doesn't Duck Hunt work on plasma or LCD screens? - Arqade

 

EDIT: Someone on youtube has been working on a solution to this problem, but it has been a year since they last updated so i have no idea if they ever finished it. If you have any doubt that this is possible, here is a video where he shows his working prototype: https://www.youtube.com/watch?v=8D624JADDOw

 

EDIT 2: A possible solution i have considered would be to connect to the expansion port on the bottom of the nintendo using an ENIO board to allow the gun to directly interface with the 2A03, but i have no idea how i would implement this or how it would actually work. It would probably need to tell the game to flash the targets on screen, then wait until the gun can determine whether or not it is pointing at a target before advancing to the next bit of code.

 

EDIT 3: I have recently tested an NES zapper on an old projection tv. This proves that the issue is caused by input lag and not the lcd screen itself, because it shows that the zapper CAN indeed work on a non-CRT television.

  • in reply to beacon_dave

    Hi Dave,

     

    That's a good idea. I was thinking of non-lightgun ways to identify the position and then trick the lightgun input at the correct time, but I couldn't think of a simple solution like the Wii 'mote. Very cool : )

  • in reply to Former Member

    I'm not clear on why modifying the zapper would not work. As long as the delay is constant, shouldn't you be able to simply introduce the same delay to the output of the trigger? You would need to make a custom cartridge with a calibration program to set the length of the delay, but that would not be that difficult.

  • in reply to cgibbons

    The problem is you're seeing it backwards.  By the time the screen draws the duck in X location, you should have ALREADY pulled the trigger.  Because there's so much delay in the display.  You can't modify the gun to get around this, it would have to be the games code so it isn't looking for an instant reaction but a delayed one.  This is why rhythm games like Guitar Hero built in delay calibration.  With the notes on screen set to 0 delay compared to the song, you can hardly play the game on an LCD but on a CRT you can play it fine.  It has to be on the software side.  It should be theoretically possible, but modifications to the NES hardware and Zapper gun it's self shouldn't be needed in my opinion.

  • in reply to beacon_dave

    Slightly Sorry for the thread bump.  This has me pondering if you couldn't take it a step further and remove the zapper completely from the equation, and just use a wiimote for the games.  Instead of outputting to an LED, use a serial output to send the signal to the console itself.  It would mean extra work per system to mimic the controller, and a serial interface, but boy would that be clean.

  • in reply to r4builder

    Subbing in a wiimote for the zapper to play Duck hunt seems the best solution I have heard yet to be able to play the game on a modern television. However, at that point, it's so much work, and likely impossible, to make the wiimote work with the original hardware that the ideal solution is probably just to emulate the game and work the emulation to work with the wiimote. Do you agree?

  • Hi,

     

    I know theme is old, but still actual!

     

    I've made two ROM modifications. Duck Hunt and Wild Gunman. With auto delay algorithm. http://neslcdmod.com

     

    It works on Famicom and Famiclones, but with chinese guns. Not sure about Zapper. I have negative reports with it.

    The problem is in demodulator in its circuitry. It prevents to react to LCD screens. So software way not helped here, I think.

    But I'm searching for simple Zapper mod solution.