JAMMA + VGA converter Wireup

[coreyr]

Hi,

Sum up I need guidance on how to hook up a VGA converter to a JAMMA board (I will be using an LCD and not CRT). I have looked around but most the information I found is showing the device in action and not the setup part (maybe i'm not looking hard enough).

The cables I had with the VGA converter is a 8pin (RED, GREEN, BLUE, GREY, YELLOW AND BLACK) & a 2pin ( RED & BLACK).

I'm starting with a fresh CAB and not an existing CAB (If that is relevant)

Thank you!

 

[Frank_fjs]

There's a few different methods of video input. Typically the 5 pin header is used but it appears you don't have that cable, either way it doesn't really matter as you typically don't use the included video harnesses anyhow. You can also input via the VGA or component inputs.

Power is either via the 2 pin wire, red being positive and black is ground, or via the DC jack. It needs 5 volts.

So on your 8 pin harness you have:

VIDEO RED
VIDEO GREEN
VIDEO BLUE
VIDEO COMPOSITE SYNC (YELLOW WIRE)
GROUND (BLACK WIRE)

You can ignore the grey wire, it's for vertical sync however most arcade boards output a combined horizontal and vertical sync signal.

A jamma harness typically has the 5 pin connector on it which connects straight to the encoder, so no additional wiring harnesses needed.

 

[coreyr]

There's a few different methods of video input. Typically the 5 pin header is used but it appears you don't have that cable, either way it doesn't really matter as you typically don't use the included video harnesses anyhow. You can also input via the VGA or component inputs.

Power is either via the 2 pin wire, red being positive and black is ground, or via the DC jack. It needs 5 volts.

So on your 8 pin harness you have:

VIDEO RED
VIDEO GREEN
VIDEO BLUE
VIDEO COMPOSITE SYNC (YELLOW WIRE)
GROUND (BLACK WIRE)

You can ignore the grey wire, it's for vertical sync however most arcade boards output a combined horizontal and vertical sync signal.

A jamma harness typically has the 5 pin connector on it which connects straight to the encoder, so no additional wiring harnesses needed.

Hi Frank,

Thanks for the reply. Let me get this straight.

I don't use the 8 pin cable that came with the converter and you saying there a 5pin connector on the JAMMA harness that will plug directly onto the converter?

I don't need to solder, wire up anything just plug and play?

Thank you

 

[Frank_fjs]

It all varies based upon usage but generally speaking, yes, the jamma harness has a standard 5 pin connector (RGBS and ground) which simply inserts into the corresponding connector on the encoder.

You can tap power from the arcade power supply.

That's all there is to it.

 

[Zebra]

Both of my arcade monitors have 8 pin molex connectors (as well as standard db15 ports). It only uses 5 of the pins though. All arcade boards output either RGBS or rbghv (aside from one's with an NTSC board for use with rear projection monitors).

If you are using an LCD monitor then you might need and upscaler board if the monitor can not accept a 15khz RGBS signal directly.

The 8 pin molex to DB15 adapters they sell on eBay as "cga to vga converters" are usually just dump port adapters to allow you to feed the RGBS wires from a Jamma harness to the db15 port on an upscaler. They are also used with tri-sync arcade monitors that can accept a 15khz rgb signal via a db15 port.

So first question is can your lcd monitor accept a 15khz signal directly? If not, do you have an upscaler?

 

[Frank_fjs]

I believe he's planning on using a GB-8200

 

[Zebra]

I believe he's planning on using a GB-8200

You should be able to wire an arcade board (via a jamma harness) directly to those arcade CGA to VGA upscalers.

They use a standard DB15 vga style port for the input so I suggest that you Google a vga rgb pinout diagram so you can see which pins are for RGB and sync. Then buy a male VGA breakout board off ebay to connect the Jamma harness wires. The breakout board has numbered screw terminals for each pin which is far easier and quicker than soldering wires to a tiny DB15 plug.

As a side note, I have one of those cheap upscalers and the quality is poor IMO. The image is OK (ish) on my 480p monitor but terrible on a 1080p panel. If image quality is important and you don't want to use a crt arcade monitor, I would suggest investing in a quality upscaler like the OSSC and use it via a Supergun (with a scart cable).