+SYNC and -SYNC

[Austin.Wolff]

On my monitor printout there is -Horizontal Sync, -Vertical Sync, and +Horizontal Sync, +Vertical Sync.  But when I look on a VGA pin diagram, there is only Horizontal Sync and  Vertical Sync.  Does negative go to ground, or do I wire the both together?

[Carlito]

From the Monitor FAQ http://forum.arcadecontrols.com/index.php?topic=45137.0

With regards to horizontal and vertical sync, this may be monitor dependent to get it to work.  Some require H- and V- from the monitor to be connected to separate H and V lines in your cable and some require them to be connected together.

[siastbill1]

If your monitor has separate -horizontal and -vertical (instead of just one composite sync), then you wire the horizontal and vertical syncs from your VGA out to their respective -horizontal and -vertical syncs on the monitor (not the + syncs).

The + syncs are just not connected at all (ie don't ground them).

[Austin.Wolff]

So I ignore the + syncs and wire the negative syncs into whatever pins?

[siastbill1]

Yah, leave the +syncs unconnected and wire the -syncs to the matching horizontal/vertical syncs on the vga. You also may have two video grounds on your board. You should be able to wire the ground from your VGA to either one, but I don't know what monitor you have so I can't say for sure. If you don't see anything on the screen, then try the other ground (or maybe even ground both).

[Austin.Wolff]

Okay so I'm having trouble again.  I can't find the model # anywhere, so ignore that.  On the pin that goes to JAMMA from the monitor, there is the R,G,B, and wires coming out, then a couple blank ones, and then GND V SYNC, H SYNC, except there is no wire coming from V SYNC, am I just reading it wrong?

[siastbill1]

Ok, you are looking at a plug that is attached to the JAMMA connector? JAMMA boards are composite sync, so that is probably why it is only going to the horizontal snyc.

If you want to keep using this plug with only one sync wire, then you can twist together the negative syncs from your VGA card and connect them both to this single sync. This trick usually works. You can also make your own cable that puts the proper syncs to the proper pins on the monitor.

Are you using a JPAC, or are you just keeping your JAMMA stuff intact?

[Austin.Wolff]

Neither, but I'm using the JAMMA plug for the monitor just for simplicity of wiring.  The rest of the JAMMA I pulled.

[siastbill1]

Ok, technically this wouldn't be a JAMMA plug, but rather just a monitor plug that was attached to your JAMMA harness. Anyways, if you want to re-use this plug, rather than making your own, I would try and do the twisted syncs method. I have successfully done this before, so I know it works.

You just twist together both syncs coming off the VGA, and then attach them to the -horizontal sync. This should be the one that is on the plug going to your monitor.

Give it a shot and let me know how it works.

BTW, what method are you using to generate the proper arcade frequencies: advancemame, powerstip, arcadevga?

[Austin.Wolff]

Ah, thanks.

It depends, I'd like to get Fedora Core back up and running on the machine I'd be using, but chances are I'll go with Powerstrip, just for the sake of not reinstalling FDC.

Also, the RGB on a VGA cable are the 3 thick wires, but when I strip them, there is two wires, one on the inside, and one on the outside.  I'm assuming one is RGB GND, but which one is it?

[siastbill1]

You can ignore the ground in the VGA's RGB wires, and just use the main VGA ground instead (much simpler).

Usually the ground wires in the RGB are wrapped around the signal wire, which itself is encapsulated by a very small casing. Therefore, for each of the R,G,B wires, you want to use the wire that is in the middle (signal), and basically strip off the bared wire that is surrounding it.

If you still can't figure out which is ground, you can use a multimeter and test the wires.

BTW, my vote is for DOS and Advancemame over Windows/Powerstrip

[Austin.Wolff]

Yay then

Why don't you like Powerstrip and Windows?  Chances are I'll go Advancemame/Linux, but not for a while.

[siastbill1]

I love DOS cause it is so pure. My boot time from post to emulator is like under 10 seconds. It has the smallest footprint out of any OS, and it just runs well. I have cloned my DOS hard drives and moved them to other arcade machines with little or no adjustments to anything. It's like using an appliance. You just turn it on and it goes to work. Amazingly, MAME stability in DOS is incredible (never had advancemame hang).

Windows/powerstip is nice cause you can do all the other Windows stuff that you would normally do, but for me, an arcade machine is an arcade machine. It's job is to play arcade games, not run Windows games, surf the web, watch movies.....