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Main => Monitor/Video Forum => Topic started by: Ummon on May 06, 2008, 05:20:11 pm

Title: RGB to VGA connector
Post by: Ummon on May 06, 2008, 05:20:11 pm
I have this RGB to VGA connector that came with my Billabs. Not sure why, as it already has one on it, but I was thinking of wiring this to the monitor in my Japanese cab instead of hacking a cable. I'm not sure of the notation on the board, though. You can see on the left it says  R G B E V H/C . Difficult to see but between the header and the vga connector it says R G B E H/C V .  Does anyone know which I'm supposed to go by? And what is C? Also, I guessing I'm supposed to connect the monitor ground to where it says 'ground'?
Title: Re: RGB to VGA connector
Post by: grantspain on May 06, 2008, 05:49:16 pm
red/green/blue/earth(ground)/vertical sync/horizontal-composite sync
Title: Re: RGB to VGA connector
Post by: Ummon on May 09, 2008, 01:41:21 am
Thank you. The E threw me.
Title: Re: RGB to VGA connector
Post by: Ummon on May 11, 2008, 08:35:44 pm
Oh, just to make sure. I don't have to connect any ground to the 'ground' marked to the left on the board?
Title: Re: RGB to VGA connector
Post by: grantspain on May 12, 2008, 03:16:56 am
Oh, just to make sure. I don't have to connect any ground to the 'ground' marked to the left on the board?
i doubt that ground needs connecting,if you check it is probably linked the "E" anyway
Title: Re: RGB to VGA connector
Post by: Ummon on May 12, 2008, 03:52:39 pm
Cool, thanks.
Title: Re: RGB to VGA connector
Post by: grantspain on May 12, 2008, 04:13:31 pm
so judging soley on the vga-rgb interface you actually have a wei ya m31 chassis,does this auto sync to frequency or are there 2 switches to change frequency and signal input voltage??
Title: Re: RGB to VGA connector
Post by: Ummon on May 14, 2008, 03:44:39 pm
I have a Billabs monitor, so yeah I guess it was a Wei-Ya. However, I'm using this for connecting to what I'm guessing is a Nanao or something in my Capcom Impress, as shown in this thread (http://forum.arcadecontrols.com/index.php?topic=80118.msg836479#msg836479).
Title: Re: RGB to VGA connector
Post by: grantspain on May 14, 2008, 06:24:38 pm
i would need to know the other chassis model for sure but have you tried linking the v and h sync yet?
Title: Re: RGB to VGA connector
Post by: Ummon on May 14, 2008, 09:50:48 pm
I tried both V and H/C. I also stuck in a little wire to bridge the two but that just made a different flavor of squirrelly. Here are some pictures of the tube and neck board and chassis. Though, if it's in a JAMMA cab and it did display with the board that came with it, wouldn't that mean the sync is composite?
Title: Re: RGB to VGA connector
Post by: grantspain on May 15, 2008, 02:57:37 am
all jamma are composite sync,
i have seen stated that the impress cab have a toei chassis
i think your issue is related to the soft 15k/card setup
Title: Re: RGB to VGA connector
Post by: Ummon on May 16, 2008, 01:57:54 am
I've used Mame32 with soft15; and without soft15 installed I've used Advancemame. Here are some pictures of the latter. The game is 88games. The first one is with the composite lead off. The second one is with it on V. The third is on H/C. The fourth is on both. However, the image on these different connections varies from game to game. They're all squirrelly, though. At least in Advancemame, the doc says if doing composite video, then to indicate it in the rc file - except I can't for the life of me find the parameter related to it.
Title: Re: RGB to VGA connector
Post by: Ummon on May 16, 2008, 02:47:54 am
Hey, good news. As you'll see below, something is different. I'm not sure what changed from yesterday, but the images below are using soft15 with the sync lead from the jamma harness connected to both V and H/C pins on the connector. (Now if I can just get Advancemame sorted out, I can get them all sized for the screen - although it's probly that polarity parameter I have to find.)

The only thing is the monitor is not quite as bright as I thought it was with the jamma board connected, but I could be wrong. I did turn with the color and brightness, but they seemed to be adjusted for the best already and I had to hunt a little to get it back to where it seemed it was. The last image is pretty good, but I turned up the brigtness in mame to 1.15 .
Title: Re: RGB to VGA connector
Post by: grantspain on May 16, 2008, 03:57:16 am
you will more than likely need a video amplifier as the vga card will sending a 0.7-1v signal to the monitor whereas the monitor(if its a cga/ega type)will be expecting a 2.5-5v video signal
Title: Re: RGB to VGA connector
Post by: Ummon on May 16, 2008, 05:11:30 pm
I remember reading somewhere that modern (anything I think 95 or newer) arcade monitors don't need amps. I think Ken said that. In any case, compared to the images I've seen of monitors that did need amps, these aren't even dim. I just thought maybe the connection wasn't quite right and perhaps there was, say, a 10% dimming. With the brightness up a little in mame, it's just fine. Anyways, thank you for your help.
Title: Re: RGB to VGA connector
Post by: grantspain on May 16, 2008, 07:37:25 pm
glad you got it sorted :cheers:
Title: Re: RGB to VGA connector
Post by: Ummon on May 17, 2008, 01:40:20 am
Not to belabor this, but now I see why these seemed so dim. There was no ambient light. However, the flash just saturated it. I don't remember if I turned on a light or even thought to. It was a long night.