Build Your Own Arcade Controls Forum
Main => Monitor/Video Forum => Topic started by: matz100 on January 08, 2004, 12:14:36 pm
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hello 8)
ive the following problem:
i bought a cabinet and want to use the arcade monitor with my pc in msdos mode. the monitor works with the buildin cardgame just fine. the game connects via a adp-adapter to the cabinet. the monitor has following inputs :ground r g b and sync. so i disconnected the adp-adapter and connected a vga-cable(with these coax connectors) with extra r g b and two sync cables to the monitor. i connected the 2 syncs to the 1 sync on the monitor and the rgb to the rgb on the monitor. all grounds i connected to the monitors ground.
the problem is that i just doesnt see anything on the monitor (its still working with the card-game and the power is also swiched on an i can "hear" the monitor)
i have a matrox mystique graphic card and i used the advcfg programm to test (i choose servral arcade settings 15-30khz)
i also tried powerstrip and a gforce2 with windows ...
and still i dont see ANYTHING on the monitor ....
i excpectet to see just some flickering or anything else
so id be very happy if anyone had some idea to get something visible ....
::)
(i just dont know the specs of the monitor ... its from 1984 :P)
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Arcade monitors expect a signal from the 0-5v range, Your vga card is outputting 0..1v, try turning up the brightness of the monitor and see if that helps.
-PMF
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thanks for the good idea :)
but where can i increase the brightness of my monitor?
is there a way to increase the volage out of my vga-card?
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brightness is controlled by an onboard dial in the back somewhere...
http://link.mywwwserver.com/~jstookey/arcade/WG_25k7191/WG_25k7191_diagram.JPG
Mine is in a different place... on a little remote control thingy...
To boost your voltage level.
http://www.ultimarc.com/vidamp.html
a possible problem: My monitor is blank if i accidently send it positive sync signals... you need both negative hsync and vsync...
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hey nice ideas :)
ok next thing i do is to check the voltage ...
i expected that every vga-card has negative output for both syncs ... at last my mystique which is often recommended
ok tomorrow ill try out ;D
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ok i made some mesurements ant the result ist :
the wireing is ok
the vga outputs only 1v
the original game about 4v
so i got to increase voltage ...
thanks for the help
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today i looked again and i found out that i realy have positive h and v-sync out of my vga-card ... how can i change this to negative output?
is there a way to do this by software or do i need some hardware solution?
another question: is there any guide to build the vga-amplifier by myself?
confused greetings ::)
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Your monitor should have H sync-, H sync+, V Sync-, V sync+. I hooked my hacked vga cable so that the horizontal sync went to the h sync- and the vertical sync went to the v sync- . This works fine. Some monitors may require you to combine the H sync and the V sync from the monitor cable to a single sync input on the monitor (this doesn't seem to be your case) To build your own vga amplifier look here: http://www.mameworld.net/pc2jamma/hardware.html
I built it but haven't tested it yet--its fairly cheap to build if you have access to electronic supplies (and radio shack won't cut it on this one)
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thanks for the guide ... ill try it
no my arcade monitor has only combined h and vsync ...
and it seems to respond only on negative values ...
ill try mon-arc plus with a vodoo3 video-adapter now ...
ill post the results soon ...
wish me some luck ;D
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It would be very helpful if we knew the make & model of your 'arcade' monitor as there are many different makes & models out there. Not all have positive and negative sync inputs. Some have positive only, some have negative sync only.
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unfortunately i dont know the model of my arcade monitor ...
it seems be be from 1984 and theres a card-game running
its labeled with "orion" and seems to be some rare? german custom machine with a adp connector ....
i just took some mesurements again and found out that i was wrong and that the monitor runs with positive sync ...
im quite sure that its the voltage level of the vga-rgb that ist to low for the monitor. the build-in game has about 5v and the vga rgb about 1v (as aready said here) ....
the sync of the vga-card seems to be nearly as strong as the sync of the build-in game
so im gonna build the vga-amplifier to get the monitor working :P
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I would guess that its more likely a sync problem than a voltage one... from what I've read, you should at least be getting a picture from your monitor (although dark) with a 1 volt signal... However, I've gotten the EXACT same thing you describe using positive syncs....
You might try powerstrip or advancemame.. I believe both allow you to specify the polarity of your sync signals.
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i did some mesurements again:
with the 2gaphic-cards i used the advcfg testscreen (CGA 15khz)
arcade_game vodoo3 matrox_mystique
r +3v +0,1v +0.1v
g +3v +1v +0.1v
b +3v +0.1v +0.1v
sync +4v +5v +3.5v
i cant really explain the +1v on green at the vodoo3 ???
and jet i cant get ANY image on the arcade monitor (only with the original arcade game)
strange :P