More Act-Labs Lightgun / ArcadeVGA woes

[GamingGreg]

My pair of Act-Labs PC USB lightguns arrived the other day, and I been having a problem getting them to work with my standard resolution monitor (old Wells Gardner K4600).  When I hook up my lightgun the display goes "screwy", as if the horizontal hold went crazy.  However I can't adjust the horizontal hold far enough to correct this, and it was adjusted fine before I hooked a lightgun up.  When I flip the calibration switch, the screen does go mostly white (still flickering wildly, and I am seeing flashes somewhat when I pull the trigger.  So it appears I'm getting close to getting this working.  (I'm using Windows XP, with my desktop being 640x480 16bit color at 60Hz refresh rate).

First I hooked the lightguns up to my standard Pc with a standard PC monitor, just to make sure they worked. And they did.  I also separated the H sync and V sync signals on the video amp, as Andy (of Ultimarc) stated in this thread, that they need to be separate to function.

Also, I saw a note on the act-labs support site that said the monitor needed to be in non-interlaced mode in order to function.  Does anyone know if this is true, as I believe 640x480 via the Arcade VGA is a interlaced mode.

Anyone have any Ideas on how to make this combination work?  It seems that some of you might have.

[Lilwolf]

Try getting frontend and mame to work in a noninterlace refresh... MultiRes is a good program to switch resolutions in XP... I don't know if it working on the arcadeVGA but worth a try.  Then let it stretch for you.   Then you don't change refreshes that is a little faster...   Later you can try to optimize the settings when you get everyting working.  I think that 640x288 or something is non-interlaced highest resolution for that card.

Next... (take this with a BIG grain of salt... because I am going by old hearsay)... I believe that it is a vertical and horizontal sync issue.  Having them both connected to sync compared to only one.  Search and see if you can find it on the board somewhere.

[AndyWarne]

Have you definitely connected both sync signals to the negative inputs on the monitor? If so..
You could try removing the amp. The W-G monitors don't generally need it. Just wire the signals from the card through to the monitor, with H and V sync separate, connected to the negative sync inputs on the monitor. Then try connecting up the gun.

Andy

[GamingGreg]

None of this thus far has involved MAME or MameWah (my front end).  It's all been just the desktop.  I'll might run into some issues with Analog+ MAME and two lightguns, but I haven't gotten that far yet.

I also did try setting my desktop to 640x288 last night, and it was somewhat better.  Instead of "wild horizontal scrolling" it would scroll slowly, but I still couldn't get to "hold still".  In both cases (640x480 interlaced and 640x288 non-interlaced), I could get a still picture without the gun connected, but never with the gun connected.

Also, I'm 99.9% sure that I've separated the H and V syncs to the monitor.  I cut the little connection on Ultimarc's video amp board (as per Andy's instructions) and now have two sync wires going to the arcade monitor.  I used a voltmeter (or rather ohmeter) to check the two syncs on the screw block, and it doesn't read zero  (I didn't read infinity either; it read 800 something ohms witch it probably some resistance in the circuitry)

I thought there were some people who had this kind of setup (act-labs gun, ArcadeVGA card, and standard resolution monitor) and had gotten it working.  Is that true?  Any more ideas as to what I might be missing?

Do these guns not work with the 15Hz refresh of the monitor?

[GamingGreg]

Have you definitely connected both sync signals to the negative inputs on the monitor? If so..
You could try removing the amp. The W-G monitors don't generally need it. Just wire the signals from the card through to the monitor, with H and V sync separate, connected to the negative sync inputs on the monitor. Then try connecting up the gun.

Andy

I've connected the vertical sync (one marked "sync" on the amp) to the negative vsync on the monitor, and I've connected the horizontal sync (unmarked  on the amp) to the negative hsync on the monitor.  Nothing is connected to the possitive H or V syncs on the monitor.  I suppose I could try removing the Vsync temporarily, just to see if they are indeed separated.   I'll also try looking for an old monitor cable that I can cut up and then bypass the amp.

So Andy, I take it you've gotten a similar setup working on your end?  Did it work in 640x480 or just 640x288?  Is there something with the refresh rates that I need to tweek with?

[jerryjanis]

My Act Labs PC USB Light Gun worked on my WGK7191 monitor after I separated the hsync and vsync.  I'm using an ArcadeVGA with a vga cable hack.  I'm pretty sure that worked fine in Windows in 640x480 interlaced mode.  I'm certain that 640x480 mode displays normally when the gun is plugged in.

When I plug in my lightgun, for some reason I typically don't plug the VGA cables tightly enough, and I get crazy screen weirdness until I turn it off and plug them in properly.  Other than that, I haven't encountered anything like the problems you are talking about, so I'm sorry that I can't be much of a help.

[jerryjanis]

It sounds to me like you've got the right idea with the wiring.  Here is a picture of the wiring on mine:

http://jstookey.com/arcade/WG_25k7191/WG_25K7191_output.JPG

And here's a diagram that points out which wires are which:

http://jstookey.com/arcade/WG_25k7191/WG_25k7191_diagram.JPG

[GamingGreg]

Okay, I've gotten things working a bit better.  I found an old VGA cord off of an old dead monitor, and I hacked it into a cable for my monitor (with separate h and v syncs).  Once I did this I bypassed the video amp with this cord.  Then I was able to get both guns hooked up, without the screen "wigging out" on me.  Thanks for all of your suggestions.

However, the guns still aren't working great.  After calibrating the guns, I found that the cursor was moving quite far from where I was aiming, making it impossible to hit anything.  It was almost a random point on the screen (not VERY accurate).  Sometimes the mouse cursor would move consistentally to the far upper right of the screen, after calibrating (a failed calibration?).

Any ideas?

*Edit*
I should also mention I tried calibrating in 640x480 60Hz.  I played around some with 640x288 & 640x240 with no luck as well, but I might not have had the refresh set properly on those.  For some reason, every time I change resolutions using that tool that came on the Ultimarc CD, it sets the refresh rate to 200Hz.  I don't know if that even matters as the ArcadeVGA limits this to 15Hz anyway from what I understand.

[JoeB]

It sounds to me like you've got the right idea with the wiring.  Here is a picture of the wiring on mine:

http://jstookey.com/arcade/WG_25k7191/WG_25K7191_output.JPG

And here's a diagram that points out which wires are which:

http://jstookey.com/arcade/WG_25k7191/WG_25k7191_diagram.JPG

I have this exact monitor.  When I got it, it had a CPS2 game inside of it, and I noticed that both the H & V synchs were connected together (same wire, looped twice) before it went to the JAMMA board.

Are we required to do this for the light gun, run just one of the wires, or run 2 seperate sync cables back to the J-PAC

[GamingGreg]

It's been determined (by Andy and others) that the act-labs VGA lightguns need a separated sync to work right.  Since the Jamma standard calls for a composite sync, I don't think you're going to get a lightgun working with a J-Pac.  There might be a way to modify the J-Pac to do this, but I doubt it.  You might want to ask Andy about that.  

Also you could bypass the J-Pac with your own VGA hack, but you'll need to insure your card (if not an ArcadeVGA) is outputing 15Hz refresh rate or you could burn the monitor out. (see the monitors section of the website for more details)

[GamingGreg]

I'm still at my witt's end on this one.    I know the guns work, as I've hooked them up to my computer with a standard VGA monitor, and they worked without a hitch the first time.

However when hooked up to my ArcadeVGA and arcade monitor, they aren't working well.  Usually after callibration, if I fire a shot, the cursor moves to the upper right hand corner of the screen.  Also I noticed that in 640x480 the white callibration screen doesn't appear pure white.  It seems to have a gradient in the horizontal axis (It goes from black to bright white by 1/4 way across the screen, and then from bright white to average white the rest of the way).  In 640X240 it appears correctly with the entire screen showing average white, however the gun still doesn't work in this mode either.

I'm starting to think my monitor has some issues (It is after all nearly 25 years old).  I'm starting to think of replacing my arcade monitor with a standard VGA monitor or TV.    Ugh!

[StephenH]

Try running at a non-interlaced (Games Native Resolution).  Additionally, amke sure the syncs are completly separated (no connection BEFORE or AFTER the gun decoder).

[GamingGreg]

I think I've found the last item that's causing my problems.  This time it appears to be the lexan (or plexiglass?) that sits between the monitor screen and the gun.  After removing this for some testing, I was able to get the gun working in a mostly playable state.  It's still not perfectly accurate, but a least the crosshair ends up within an inch of the sight after the trigger is pulled. However, accuracy gets worse when I put the lexan back on.

I'm not sure if my original issue was because the gun was not calibrated close enough to the screen (because of the gap between the lexan and the screen), or because of the many scratches on the surface of the lexan that are interfering somehow.  Maybe both.

My cabinet is a conversion of an old Defender cabinet (which had already been badly converted a few times over before I got it), so that piece of 1/4" lexan has been used many years.  You don't normally notice the scratches unless you look close.

Any ideas what I should do?  Should I get a new piece of lexan or plexi? Should I just polish the lexan with that Novus plastic polish stuff? Should i get a piece of tempered glass instead?  Smoked glass?  Opinions please.