Will Light Guns work with RGB to VGA connector on a CRT Monitor?

[captaincatalyst]

I've experimented with the AimTrak and just can't get it to the point were I'm satisfied enough to want to keep playing a game, so I'm looking into buying an actual game pcb with gun, such as one of the Sammy hunting games.  If I use a CRT computer monitor and an RGB to VGA adapter to get the video onto the monitor, will light gun games work?

Thanks!

[bimm25e]

I've been in your shoes and you're going to have a tough time finding a lightgun that is CRT based AND has a PC interface.


google it cause I don't have a link but I believe people have had success with the "WARZAID" lightgun kit - but that kit is $450 If memory serves

[captaincatalyst]

I've been in your shoes and you're going to have a tough time finding a lightgun that is CRT based AND has a PC interface.


google it cause I don't have a link but I believe people have had success with the "WARZAID" lightgun kit - but that kit is $450 If memory serves

Thanks for the reply.  I'll look into that, but my main goal right now is to get an actual arcade PCB and hook it up to a computer monitor.  For example, if I buy a Big Buck Hunter PCB and gun, can I get the light gun to work on a CRT computer monitor if I use an RGB to VGA adapter?

[bimm25e]

Ohhh cool, well the key is going to be making sure the refresh rate is not inhibited - I know computer CRTs typically support much higher refresh rates than old CRT monitors so it will be important that the CRT doesn't "upconvert" ie. make your 15Khz signal a 60Khz signal that would effectively hose the way the lightgun sensor works.

I think it will be important to avoid any type of "signal converter" they way I understand it VGA carries an RGB signal - the more "inline" your adapter is the more likely you'll succeed.

You'll definitely want someone else's opinon, im a still a newb... but I think you'll be looking for a very specific configuration to make everything work right. It might be tricky to hit all your marks on the first try.

[lilshawn]

the way a light gun works is going to be inhibited by any kind of digital processing you may introduce.

the way it works:


the light gun has a sensor that produces a pulse when the light entering it reaches a predetermined threshold.

when you are playing the game, the sensor  board outputs nothing. when you pull the trigger, 2 things happen... the computer starts counting...and the computer sends a frame of white to the monitor.

monitor begins overwriting the image with white...the time it takes for the beam to scan, starting from the top left...until the sensor picks up the light from the screen turning white is where the position is. this is usually done ~10-12 times to get an average of position to account for noise or voltage fluctuations. (at least on the big buck hunter games it is)

the time for a single frame to be "written" to the screen is 16.67 milliseconds.

can you see where the problem is?

any kind of convertor is going to introduce frame processing time and introduce lag to the image. While this wouldn't be a problem with say a fighting game or space game where a delay of 10 milliseconds to display a frame is no big deal... but 10 milliseconds in the scope of 16.67 milliseconds...the computer is expecting the screen to have been 3/4 drawn by now.

thus you end up with a gun whose aim is nackered in the corner no matter where you shoot.

that said, lots of CRT monitors support the resolutions these gun games run in. If you can manage to run it in it's native resolution, it will work no problem. most Sammy games (extreme hunter etc) that run on the Atomiswave platform will run at 640x480 with a couple flips of some dip switches...and they also have a VGA output on them which is perfect for just plugging in a VGA monitor.

[MonMotha]

BBH runs VGA 640x480p (or at least can and does in the dedicated cabinets), so you don't need any converters.  Just plug 'er in.  The monitor in the cabinet in fact has the typical "VGA" HD15 connector on it and expects PC compatible signal levels.

BTW, VGA *is* RGB.  The only difference between the output of a classic arcade game and a PC is the video resolution (240p/480i 15kHz for standard arcade res vs. 480p 31kHz for PC VGA) and signal levels (0.7Vpp for PCs but ~3.5Vpp for arcade games).  The latter is easily fixed with a few well selected resistors.  The former can require scalers which will break light guns, but many of the late-model games had selectable 15k/31k video modes via e.g. SIP switch.

[captaincatalyst]

Thanks for the info!  I'll see what I can come up with.  I've got a Sammy "TROPHY HUNTING Bear&Moose" and gun on order, but don't currently know what the options are for native video output.  I'd love got get an Atomiswave with Extreme Hunting going at some point.