Issues with the Act Labs TV lightgun

[SuperBoB2Turbo]

I got my Act Labs TV light gun a couple of days ago.  I tried it out with mixed results.  This is the first lightgun I've tried with MAME, so I don't know how much of this is already known.

First, on calibration.  The 'instructions' tell you to move the gun vertically and horizontally across the screen.  Well, I was having the same issues some other people on here were having with HORRIBLE calibration.  Finally, I figured out that you must go right up to the edge of the screen, but NOT PAST THE EDGE.  When I go past the edge, that's when i get the shots off by three inches, like others have mentioned.  Do you guys agree with this.  If so, Act Labs should really update their instructions.  The arrows on the diagram clearly go beyond the edge of the screen, and the written instruction don't clarify one way or another.

Secondly, once I have the gun calibrated properly.  A disappointingly high number of shots 'misfire'.  If I aim off-center, say, 1/3 down and 1/3 over, then i can shoot 20 or 30 shots and they almost all register accurately give or take a quarter inch. BUT, if I aim at the middle of the screen and start firing, I would say as high as 1 in 4 shots register WAY off target, sometimes at the EDGE of the screen. Has anyone else seen this.  Is there a way to fix this (I hope)?

I didn't expect these guns to be perfect, but firing correctly only 3 out of 4 shots makes most gun games of any skill not worth playing.

On a side note, I noticed in the old nintendo gun games like duck hunt and hogans ally, even when the shots would hit as aimed the game seemed to not always register them.  Anyone know anything about that?

[Bill_S]

I haven't seen that behavior.
What TV are you using?
I'm running a Toshiba 27A33 I think it's called.

My main issue is getting 2 guns to work in MAME.

[SuperBoB2Turbo]

I have a pretty nice TV--a 25" Sony WEGA Trinitron using the S-Video input.  So, I would hope it's not a compatability issue with the TV.

[u_rebelscum]

First, on calibration.  The 'instructions' tell you to move the gun vertically and horizontally across the screen.  Well, I was having the same issues some other people on here were having with HORRIBLE calibration.  Finally, I figured out that you must go right up to the edge of the screen, but NOT PAST THE EDGE.  When I go past the edge, that's when i get the shots off by three inches, like others have mentioned.  Do you guys agree with this.  If so, Act Labs should really update their instructions.  The arrows on the diagram clearly go beyond the edge of the screen, and the written instruction don't clarify one way or another.

I go beyond the edge of the screen while calibrating and my gun calibrates fine.  (cheap daewoo w/ composite in TV)

I can see problems happening if your TV is shiny chrome or silver, or with strong lighting on it (especially from behind), maybe.  (Aren't wega's often silver?)

Secondly, once I have the gun calibrated properly.  A disappointingly high number of shots 'misfire'.  If I aim off-center, say, 1/3 down and 1/3 over, then i can shoot 20 or 30 shots and they almost all register accurately give or take a quarter inch. BUT, if I aim at the middle of the screen and start firing, I would say as high as 1 in 4 shots register WAY off target, sometimes at the EDGE of the screen. Has anyone else seen this.  Is there a way to fix this (I hope)?

There is a minor bug that if you shoot exact center, the shots are off.  But it only happens if you shoot the exact middle (either up/down or left/right).  If you shoot the exact middle of left/right, for example, the shoot is off by a very small, but random, amount.  If you shoot the exact middle of the screen both horizontally and vertically, the shot is off by much more, sometimes to the edge.  It shouldn't happen too often, though, because by "exact" I mean the middle 1/257th area.

If you want to compile your own, I can tell you what to do to fix this problem.  However, I'll also tell you problems introduced with it, too.

On a side note, I noticed in the old nintendo gun games like duck hunt and hogans ally, even when the shots would hit as aimed the game seemed to not always register them.  Anyone know anything about that?

I'll test it out.

[SuperBoB2Turbo]

My Sony is silver, so that's probably what's happening with the calibration.  Guess it's time to install a bezel  

You're right about the exact center thing.  When I'm shooting at the center I'm aiming at the default reticle that MAME puts on which is in the exact center.  And since I'm such a good shot   I probably am hitting the center a lot  

I would be interested in hearing about the bug fix.

Thanks for the help!

[1UP]

Also, try shooting in bursts of 2-3 shots, and reloading every time.  Most gun games are too fast paced to be sharpshooting every time, so I always just aim and fire 3 shots, one of which will always hit.  This should help since you're saying that the shots only misfire some of the time.

I don't have the guns yet, so can't help more than that...

[night]

ive had my guns for a week and im just now getting around to trying it.

it works fine as the mouse. and registers in mame. but it wont give the shoot sound or actually shoot  
all i know to try right now is area 51. cant remember any other games. i have HOTD2 but it crashes on loading in win98  

[u_rebelscum]

You're right about the exact center thing.  When I'm shooting at the center I'm aiming at the default reticle that MAME puts on which is in the exact center.  And since I'm such a good shot   I probably am hitting the center a lot  

I would be interested in hearing about the bug fix.

Thanks for the help!

Okay, the fix I was thinking of doesn't make the jump go totally away on my system, but seems to reduce the jump.  Might be different on your system.  What it does is override any analog sensitivity setting, thus making playing anything besides a lightgun more difficult.

Okay, outline: mame is coded so that if no lightgun is installed and the -lightgun option is enabled anyway, you can still use the keyboard for input.  This is done by starting the crosshairs in the center; mame calls this (0,0) internally.  Then mame checks if lightgun X <> 0, use the lightgun X axis data to locate the X axis of the crosshairs, else use last X value of "normal" inputs to do so; repeat for the Y axis.  The normal inputs are the keyboard, mouse, and joysticks.  Now, since the lightgun is also a mouse, albeit with irregular data, and the mame reads the "mouse" differently than a lightgun, the lightgun data read as a mouse is way wacko.  Moving a mouse from the left side to the right side of the screen 1024 width usually totals a delta reported to mame as 1024; with the lightgun the delta is 65535 no matter the screen width, at least in winME/9x.  (And on a 1024 wide screen, a one pixel sideways move is 65535/1024, or 64, which mame treats as 64 pixels)

The easiest fix would be to remove that if lightgun <> 0 check.  

With mame 0.76, comment out (ie: add two slashes "//" at the begining) the four lines 2114, 2119, 2123, 2128 in src/inptport.c.  It will look something like this:

Code: [Select]

   if (axis == X_AXIS) {
//      if (lightgun_delta_axis[player][X_AXIS] || lightgun_delta_axis[player][Y_AXIS]) {
         analog_previous_axis[player][X_AXIS]=0;
         analog_current_axis[player][X_AXIS]=lightgun_delta_axis[player][X_AXIS];
         input_analog_scale[port]=0;
         sensitivity=100;
//      }
   }
   else
   {
//      if (lightgun_delta_axis[player][X_AXIS] || lightgun_delta_axis[player][Y_AXIS]) {
         analog_previous_axis[player][Y_AXIS]=0;
         analog_current_axis[player][Y_AXIS]=lightgun_delta_axis[player][Y_AXIS];
         input_analog_scale[port]=0;
         sensitivity=100;
//      }
   }
It might act differently on different versions of mame than on my system (winME): I can use the keyboard until I use the lightgun/mouse/trackball, then I can't use the keyboard for any player.  WinXP might let you control player 1 with a lightgun and player 2 with the keyboard at the same time, or never let you use the keyboard.

[Smack]

I'm gonna give that a whirl later today myself.

Just curious, do you plan on adding that little fix to your port of analog mame+?

Smack

[Howard_Casto]

About the hogans alley/duckhunt issues......  On the old nes (and i'm assuming the arcades as well) the lightgun was a "half gun" that didn't calculate the screen rather it replaced the characters with large bright squares when you fired.  If your gun was pointing at one the hit would register.  What this means is large, inaccurate targets that were farily easy to hit.  

As these guns don't work this way, you have smaller (particularly in duck hunt) more precise targets.  They do work with the gun, you just have to be REALLY accurate.  In other words line up your shot with both sites.  

[StickyC]

This may or may not be a factor, but I remember reading somewhere on the packaging for my Playstation 2 GunCon that it doesn't work with Wega sets, something to do with the scan rate. Sorry I dont have any more info, but that might be something to look into.

[SuperBoB2Turbo]

About the hogans alley/duckhunt issues.....

HowardC,
I agree with you on how the old nintendo games work.  But, I'm not really sure how MAME is emulating them.  It seems possible that MAME could register a hit if you shot when the position is anywhere within the square that the game flashes.  Again, I have no idea how MAME actually handles it.  But it's too bad if it can't handle it that way.  Those old nintendo games are still some of the best gun games, IMO.  And it really sucks when you can barely make it past level 1 of Duck Hunt when you know you use to be able to get to level 7 or 8 no problem.

I remember reading somewhere on the packaging for my Playstation 2 GunCon that it doesn't work with Wega sets

StickyC,

I looked into this a little. My sony has a feature called Velocity Scan Modulation (VSM).  It supposedly changes the scan rate at points of transition of light to dark or vice versa, but speeds up in other places so that the overall scan rate is the same.  This sounds like it could very well have an effect on a lightgun.  However, when the gun actually takes a reading, the whole screen flashes white, and with no light/dark edges, the VSM might not kick in.  I am able to turn this feature off, so i will try it, and see if it makes a difference.