Wiring an external port?

Tupin

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Wiring a VGA port?

Okay, I edited this thread because I'm going to use a VGA port now. I still have a question:

Do I just ignore what pinouts call the "Monitor ID"? Also, do I just ignore vertical sync and hook up composite sync?
 
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Will I run into any problems doing this?

I'm going to take the RGB, ground, and sync wires from a JAMMA harness and solder each one to the appropriate pin of a VGA connector. I guess I can always go back to wiring it like an Apple Performa.
 
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I don't know the details of a Supergun, but in general, you just need to connect the RGB, ground and sync signals to a VGA connector. (pins 1,2,3,5,13/14) You don't need to connect the ID/DDC signals.
 
Also depends on what you plan on using as a monitor.
What are you planning on plugging into that VGA connector.... a PC monitor ?
Some will accept the single composite sync on just the horizontal pin, some won't.
 
That or a TV with VGA ports. I've heard that RGB can't be wired to a VGA port directly. I was going to wire it like an Apple-style monitor and put an adapter on it, which I know will work. Can I wire it to a VGA port directly?
 
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You can't display video from a Jamma game on a VGA monitor. Arcade games are 15.75khz, standard VGA is 31.5khz. That said, some devices with "VGA" ports, such as studio monitor/televisions might be able to sync to it. Similarly, Apple monitors intended for Macintosh computers cannot work with that signal either. But, the AppleColor RGB monitor, intended for the IIgs, will work perfectly - it's a 15.75khz monitor. It's what I use on my test rig.

Ignore the Monitor ID lines - that's a function for newer SuperVGA monitors to be able to send an ID string to the computer to tell it the capabilities of the monitor (that's how Windoze knows you've connected a ViewSonic GS771 or whatever).

Most PC monitors really want separate syncs - but some accept composite sync on the Hsync pin - but again, you can't use arcade video on a PC monitor.

While you can't use a regular VGA monitor, you can use a monitor intended for the Commodore Amiga, Atari ST (color only), Apple IIgs, or one of the many third party monitors, like the Ampex 600, the original NEC Multisync or Multisync 2a, and many others. Sony studio monitors also frequently take RGB video, as do most other commercial video monitors.

Another option would just be to use a real arcade monitor - just remember to use an isolation transformer if you do.

-Ian
 
Well, I was planning on wiring the port so I can plug a Mac-VGA adapter into it and use it on a TV with VGA ports. I'd like to do that so I can use a decent sized TV rather than a 12' monitor.
 
I guess I'll use the AppleColor monitor. It says I need a ground for all three RGB signals, can I just use any ground?
 
Jamma video ground is on pin14 of the Jamma edge connector. Connect all three video grounds from the monitor together, and connect them to the video ground from the game board. The only reason the computer monitor has three seperate video grounds is because the cables used for computer monitors have coaxial screened cables inside for the analog video signals - and their shields are used for the video ground.

-Ian
 
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