Build Your Own Arcade Controls Forum
Main => Monitor/Video Forum => Topic started by: bobbyblank on January 30, 2008, 10:18:07 pm
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Hello, i have a WG 25k7401 which i hooked up to my computer today. Once i respliced all the wires which were cut, and finished my cable, this is what i saw. On starting the computer,i had diagonal lines which i forgot to take a pic of. I know the computer was at the login screen so i just pressed enter to log on and then they went horizontal. You can kind of make out some stuff on the screen very faintly, but it looks like there is two. I havent touched any ver, hor, or any other adjustments since it was taken out of the cab. I did disconnect the vertical, horizontal, and degauss, but i hooked them back up. I attached a pic of the monitor working before i removed it. Any suggestions would be great. Thanks again!
(http://i170.photobucket.com/albums/u261/bobbyblank/IMG_0720.jpg)
(http://i170.photobucket.com/albums/u261/bobbyblank/IMG_0718.jpg)
(http://i170.photobucket.com/albums/u261/bobbyblank/IMG_0622-1.jpg)
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they are actually VERTICAL bars ;D
likely caused by feeding a 31-35khz signal to a 15khz monitor.
vert appears locked and horiz is displayng 2 h blanking bars and trace video...
suggest drop comp resolution to cga/ega settings and retry - ?
qrz
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lol, yes, vertical! haha OOPS! I will try that tonight.
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well, i tried with resolution at 640 x 480 at 60hz and still getting much of the same results. pretty much nothing lol. I did not see anything which would let me go to CGA/EGA/VGA or any settings like that. Im not much with display settings and what-not though. I am useing a GeForce FX5200 if that helps any.
Still getting lots of this.....
(http://i170.photobucket.com/albums/u261/bobbyblank/IMG_0724.jpg)
(http://i170.photobucket.com/albums/u261/bobbyblank/IMG_0723.jpg)
(http://i170.photobucket.com/albums/u261/bobbyblank/IMG_0722.jpg)
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no h sync on later pics ...still leaning towards a signal issue .
have that "nomai", in which, to test this ??
qrz
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no h sync on later pics ...still leaning towards a signal issue .
have that "nomai", in which, to test this ??
qrz
going to have to be a little more "idiot frendly", i dont know what your asking lol. I dont know how to change the signal on my video card.
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640 x 480 is still vga. Your monitor is a CGA monitor. Your computer won't work with this monitor without some kind of interface. What exactly are you trying to accomplish?
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there are three main different frequency signal used by video games
cga=15khz=low resolution(nearly all jamma game boards)
ega=25khz=medium resolution(from early 90's used for better definition graphics)
vga=31khz=high resolution(found on later game boards)
your monitor is a cga type so it is expecting a cga signal
your graphics card outputs vga so it is sending a high resolution signal
the monitor cannot use that signal which why you see two pictures
you have a photo of a sega naomi system running,the naomi systems could output 31khz and 15khz via a dil switch
if you want to run this monitor from your pc you will need some like an arcade vga card
http://www.ultimarc.com/avgainf.html
this card converts the 31khz signal from your pc to a 15khz signal which your monitor requires
also your cable is incorrectly wired
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also your cable is incorrectly wired
Thanks for all of your info, but that comment is kinda broad. I dont know what could be wired wrong in my cable. I wired it as shown in the diagram here.
(http://i170.photobucket.com/albums/u261/bobbyblank/pinout.jpg)
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just a stray thought ..... is your 'puter outputting "sync on green " ?
meaning , sync is also on the green video line ....that could account for the pic
qrz
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You need to do several things.
1) Get your computer to output CGA timed video. Most modern video cards are capable of this, but they need a little coaxing since most people have no desire to run that mode, and hence there's normally no easily selectable option. In Windows, try PowerStrip or the "Soft 15kHz" thingie. In Linux, it's a simple matter of chucking the proper modeline in your xorg.conf. Any nVidia card GeForce4 TI or newer (so any of the 5/6/7/8000 series, too) should work. ATi, I seem to recall anything that's newer than the now rather ancient 9000 series works.
2) Get your sync signals correct. If your monitor accepts separate sync, use that. Most PCs by convention output positive separate sync, so be sure to set things up correctly. Most video cards do support composite sync, again with the caveat that it's not always easy to configure. You can try that, too. In this case, you might as well set things up for the arcade convention of negative composite sync as the polarity adjustment is usually right next to the sync type adjustment. I could tell you exactly how to do this in Linux, but I have no clue about Windows. Some video card drivers do provide a GUI for this, though. I know my old ATi Rage Pro did.
By convention in the PC world, composite sync appears on the horizontal sync output, with the vertical output unused. Despite what that diagram recommends of twisting two sync wires together, I cannot recommend it. I will often work since CMOS/TTL low-side drivers tend to out-drive their high-side drivers, but it's not exactly a good thing. Far better to just get hte device to output real composite sync in the first place. If there's no option, you can build a very simple circuit (one readily available chip) to do it for you, including polarity fixing.
Note that sync-on-green, sometimes used with professional workstations, is not readily compatible with arcade monitors. Fortunately for you, PCs almost never use this without being specifically told to.
The ArcadeVGA is basically a bog-standard ATi card with a bunch of software and some bootup mods to give you a pretty interface for all this. There's no reason that this device is REQUIRED, despite what many may tell you. For me, I see no reason to spend that kind of money, but if you don't want to futz with it, it may help you out. From what I've seen, the device (and mostly the software/drivers it ships with) certainly do make things a bit easier. If you can't get things to work with your current setup, you may want to try this.