Famicom World

Family Computer => Famicom / Disk System => Topic started by: user34 on September 17, 2008, 01:10:54 pm

Title: Famicom 100Hz LCD Light Gun
Post by: user34 on September 17, 2008, 01:10:54 pm
There is something so that to can I play again Duck Hunt on the LCD / plasma?

Sorry 4 my Bad English :D
Title: Re: Famicom 100Hz LCD Light Gun
Post by: UglyJoe on September 17, 2008, 01:42:33 pm
Won't work, I'm afraid.  The way the Famicom and Zapper talk to each has a dependency on a TV's 60Hz refresh rate.
Title: Re: Famicom 100Hz LCD Light Gun
Post by: michaelthegreat on September 17, 2008, 11:48:57 pm
Actually that while that is true for the snes, the nes/famicom lightguns can work with plasma/lcd screens. The issue isn't the technology, it's the timing and/or ghosting. A good screen with little/no ghosting or lag will work fine with a nes/famicom lightgun.
Title: Re: Famicom 100Hz LCD Light Gun
Post by: 133MHz on September 18, 2008, 12:09:03 am
You're right, but even a very very small decoder/scaler delay and your shots won't register.
Title: Re: Famicom 100Hz LCD Light Gun
Post by: michaelthegreat on September 18, 2008, 01:28:05 am
True, won't work with everything. If your tv gives you the option to leave the picture small, try that. Try through your receiver and straight to the tv.
Title: Re: Famicom 100Hz LCD Light Gun
Post by: Jero32 on September 19, 2008, 07:42:08 am
Pretty sure the lightgun is made to work only with 60 hrtz. I know a guy (kevin horton) he made the so called "kevtendo" nintendo on an fpga anyway he told me once he had to modify his lightgun to work with the refresh rate of his vga monitor :-/
Title: Re: Famicom 100Hz LCD Light Gun
Post by: michaelthegreat on September 21, 2008, 02:01:03 am
I'll try to take a video for you sometime, but the nes lightgun has no kind of scanline counter. There are timing issues in that most games will make the screen's targets go white then black. They go white so that the gun registers "white" where you aimed. Then they go black, so you can't cheat by shooting at a turned on lightbulb. If there's any kind of lag in your tv's upscaling, you won't be able to register hits because the picture will be behind when the nes expects the white then black.

This is the same reason that some people had trouble with Guitar Hero and their large tv's. If there's lag, the picture gets behind the music. This is why Guitar Hero 2 has a calibration option.

It could be that kevtris had to do some work to get the timing to work right. I dunno.

Now the snes light gun does scanline counting and will only work with a CRT.
Title: Re: Famicom 100Hz LCD Light Gun
Post by: Jero32 on September 21, 2008, 02:03:17 am
the mod doesn't work for lcd's but the lightgun DOES work at a certain refresh frequency. (and yes I know how it works)
Title: Re: Famicom 100Hz LCD Light Gun
Post by: 133MHz on September 21, 2008, 10:58:25 am
The Nintendo Light Gun has a simple low-pass filter capped at around 16 kHz (standard TVs work at 15.7 kHz), presumably to make it more immune to stray interference from fluorescent lights and such. Kevin Horton just replaced a resistor with one that bumped the filter to ~32 kHz, allowing the gun to work with his 31.5 kHz VGA monitor.
Title: Re: Famicom 100Hz LCD Light Gun
Post by: Jero32 on September 21, 2008, 02:12:25 pm
See? I was right.....just didn't remember the exact details
Title: Re: Famicom 100Hz LCD Light Gun
Post by: 133MHz on September 21, 2008, 02:22:25 pm
Both of you are right, it's just that you're talking about different things :P.
Title: Re: Famicom 100Hz LCD Light Gun
Post by: PatMan33 on September 25, 2008, 06:59:00 am
So that means it can be done? ???
Title: Re: Famicom 100Hz LCD Light Gun
Post by: Jero32 on September 25, 2008, 08:28:26 am
Not for lcd's or plasma's but for crt's yes.
Title: Re: Famicom 100Hz LCD Light Gun
Post by: 133MHz on September 25, 2008, 03:14:50 pm
Yup, you can make the Zapper work with CRT VGA monitors by replacing a single resistor, but then you'd have to build the right interface to connect it to the computer, write the software/drivers to make it work, etc.
Title: Re: Famicom 100Hz LCD Light Gun
Post by: user34 on September 26, 2008, 09:14:55 am
So is the Famicom Light Gun not compatibel with LCD / plasma TV? Shame: (
Title: Re: Famicom 100Hz LCD Light Gun
Post by: Jero32 on September 26, 2008, 10:56:02 am
ya it was because lcd'' s always have some lag I think.
Title: Re: Famicom 100Hz LCD Light Gun
Post by: 133MHz on September 26, 2008, 01:49:24 pm
It's not only the lag (besides, CRT based HDTVs also have lag which breaks target detection), but also LCD screens don't refresh like CRT screens do (no strobe effect) and also they don't emit light like a CRT does, so if you point the light gun to a flatscreen, it won't 'see' anything.

AFAIK, the NES light gun also depends on the CRT screen strobing effect to tell that it's really pointing to a TV screen.
Title: Re: Famicom 100Hz LCD Light Gun
Post by: UglyJoe on September 26, 2008, 02:01:34 pm
Quote from: 133MHz on September 26, 2008, 01:49:24 pm
and also they don't emit light like a CRT does, so if you point the light gun to a flatscreen, it won't 'see' anything.


Flatscreen LCD, you mean?  I've tried using the zapper with my LCD and it does occasionally register shots (that is to say, it hits the target I was aiming for).  Maybe it can't see as well as it needs to, but I think it can still see.
Title: Re: Famicom 100Hz LCD Light Gun
Post by: 133MHz on September 26, 2008, 02:18:35 pm
Whoa, cool! Judging by the ~16kHz low pass filter inside the Zapper I've thought that it used the CRT refresh as a way to ensure that the gun is pointing to the TV screen, since it won't work on a VGA monitor even if it's CRT unless you modify it.