Do jamma gun games work on a supergun?

[ASSEMbler]

If I get a jamma game that uses a gun, will it work on a tv using a supergun?

[Calpis]

It depends on the game (the gun) and your display device.

[retro]

Kyuusaku's right - there are a lot of factors. A JAMMA standard gun game would have to be pretty old. Virtua Cop was Model 1, house of the Dead Model 2 and Time Crisis was its own standard.

The other factor of course is having the gun for it! You can hack some console guns, as most light guns work in the same way, but it isn't really the same!

[ASSEMbler]

Konami games

[retro]

Up to Lethal Enforcers, maybe. Lethal Enforcers II was custom.

[Calpis]

I assume he's using the original guns, the thing is some guns (games) need to synch to specific specific displays.

[Zilog Jones]

Would the Lethal Enforcers gun work on a normal TV? IIRC, the cabinet was weird - the monitor screen was placed horizontally under a mirror at 45 degrees. What the hell was that about?

And would a light gun designed for a rear projector display (like the House of the Dead games) work on a normal CRT?

Actually, how the hell do light guns work?! It always confused me. I remember if you pointed them at other lights it sometimes worked...

[Alchy]

Most of them work like this: the screen goes black for 1 frame when you fire, and the object that is shootable becomes white. The gun detects whether it's pointed at a light or dark object and tells the game either that you hit white or you hit black. So point your gun at the lightbulb and you'll (probably) get a hit every time, since it thinks you hit the white bit.

[Zilog Jones]

Oh yeah, I noticed that when playing some old NES gun games... but what about modern stuff? I used to finish House of the Dead frequently in the arcade with my brother (so many 50p's wasted...), and I never noticed any flickering when shooting stuff. And I usually notice that kind of stuff - I can tell if a VGA monitor is running at 60Hz or lower just by looking at it.

[Alchy]

Yeah, me too. The same principle would apply if the game was running at a much higher frequency though, and at 100Hz or something you might not notice a single frame flicker. I'm not sure what frequency recent arcade games/monitors are capable of, but it seems likely they'd up them if possible.

[Zilog Jones]

AFAIK they all still use around 60Hz, but the flicker is much less noticeable on TV-type interlaced monitors. It would be too hard/expensive to try and get a game running faster than 60fps anyway - it's a pretty good (not to mention common) value to work with for graphics rendering. They could use 120Hz prog. scan monitors but it'd probably double the cost of the display system, and if the actual game's still only outputting 60Hz interlaced it'll look like shit when there's fast movement or anything. Then again, it would probably be easier to make the game systems output progressive video than interlaced these days...

[retro]

Original HOTD? Standard medium resolution monitor (25kHz, 60Hz vertical scan). They should all be medium res.

[Zilog Jones]

What resolution are medium resolution monitors? I take it standard resolution ones are 480 lines just like NTSC TVs, but after that I'm lost...

[retro]

STANDARD RESOLUTION

HORIZONTAL___________________VERTICAL
Scan Frequency: 15.72 KHz____Scan Frequency: 60.0 Hz
Scan Period: 63.6 µSec_______Scan Period: 16.7 mSec
Active Video: 46.9 µSec______Active Video: 15.3 mSec
Video Delay: 11.9 µSec_______Video Delay: 1.2 mSec
Sync Pulse: 4.7 µSec_________Sync Pulse: 0.2 mSec
Scan Line: 456 Pixels________Screen: 262 Lines
Resolution: 336 Pixels_______Resolution: 240 Lines
Clock Freq: 7.16 MHz



MEDIUM RESOLUTION

HORIZONTAL___________________VERTICAL
Scan Frequency: 25.00 KHz____Scan Frequency: 60.0 Hz
Scan Period: 40.0 µSec_______Scan Period: 16.7 mSec
Active Video: 32.0 µSec______Active Video: 15.4 mSec
Video Delay: 7.2 µSec________Video Delay: 1.2 mSec
Sync Pulse: 4.0 µSec_________Sync Pulse: 0.2 mSec
Scan Line: 640 Pixels________Screen: 416 Lines
Resolution: 512 Pixels_______Resolution: 384 Lines
Clock Freq: 16.00 MHz



Left off Extended and VGA20 ;)

[AntiPasta]

Goddamn Model 2 board and it's 24khz (or 25, whatever) - it won't work on a TV :angry

[Calpis]

Yea.. too many games won't just work on a TV :( Everyone needs a video transcoder/updown scanner so that your display is up for any video.

[Zilog Jones]

That's the exact same table I was looking at when I posted last, retro. It doesn't make sense though - standard 15kHz/60Hz monitors can do 480 (or 486 or whatever it really is) horizontal lines - I don't know where that table is getting those numbers from...

[Calpis]

Yeah those numbers don't look quite right but it might be correct. Most game's internal res is ~320x240 (240p) displayed as 480i

[retro]

In case you didn't know.....

CGA 640 x 200
EGA 640 x 400
VGA 640 x 480

(SVGA 1024 x 768, XVGA 1024 x 768 etc.)

Hope you're not going on cruddy MAME to compare your screen resolutions ;)

What is your definition of "standard"? I gave you the definition of standard resolution. And that isn't the resolution if you see what I mean - you can get standard resolution CGA or EGA, or medium resolution CGA or EGA. Your "standard" monitor is a Standard resolution VGA monitor if it does 15kHz at 640x480.

[tom61]

Would the Lethal Enforcers gun work on a normal TV? IIRC, the cabinet was weird - the monitor screen was placed horizontally under a mirror at 45 degrees. What the hell was that about?

That way the curvature of the monitor is canceled out, which means you can shoot the sides and corners easily. If it wasn't reflected off a mirror, hitting things on the sides and especially the corners would be harder.

Light guns work in one of three ways;
1. The NES-like make screen go black and highlight targets as white and see if the gun can see white.
2. Painting the screen white until the pixel group the gun is looking at turns white, most games use this type from what I can tell
3. The freaky light-pen like guns that are capable of measuring the pixel decay (how long since the electron beam has hit that pixel) to determine where it's pointed at. No painting the screen or target white at all. These guns are capable of tracking constantly, and some games have a target reticle that moves with the guns. If you look in the gun and see a red light shinning back at you, then most likely it is one fo these guns. Naturally, you can't have any black where you can shoot, so most games using these are colorful.

I actually have a home console that works using the third method:


Once you get the TV calibrated, it's rather interesting to watch the target symbol track where the guns are pointing in the menus. Seems to flash the screens anyway in game though, for some reason. Basically, this is Point Blank in a box. If it wasn't such a PITA to get the TV calibrated for this game, I'd play it more often.