VGA monitor set-up

Questions about the RaspberryJAMMA adapter.

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strider88
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VGA monitor set-up

Post by strider88 » Wed Jun 06, 2018 7:06 pm

Hello,

Just ordered an ARPICADE with vertical set-up (from HighScoreSaves) for my cocktail JAMMA machine. It’s a converted Ms-Pac cocktail that I converted to Jamma with a VGA input LCD monitor in it. Can someone explain how I get the video signal out and to the VGA input I have on the monitor. Pictures and links would help, just not familiar with the hardware.

Do I need an HDMI to VGA cable or is there a way to just go VGA to VGA?

Thanks for any help and guidance

Mat

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Re: VGA monitor set-up

Post by dee2eR » Thu Jun 07, 2018 2:54 am

It's very easy to get VGA, no need for extra hardware. All you need to do is unplug the DAC (which is a HDMI to VGA converter) from the JAMMA side and plug your VGA cable into it directly.

Assuming you need it to be in 480p as well you can change that in /boot/config.txt, it's just one line to change (from ARpiCADE 3.8 everything else is automated, in earlier versions you would want to change video settings through the service menu to be sure all necesary changes are made):
hdmi_mode=1
is the right settings for 480p (the default setting is 6, just change the 6 to a 1).

Hope that helps. If you're not sure when you get the hardware let me know and I can help further.

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Re: VGA monitor set-up

Post by strider88 » Thu Jun 07, 2018 5:01 pm

Thanks for the info. So is the DAC (black box) used at all anymore in this scenario and the audio still remains hooked up through it correct?

I should receive mine in a couple days and will update to my progress.

Thank you for the quick and detailed reply-

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Re: VGA monitor set-up

Post by dee2eR » Fri Jun 08, 2018 5:10 am

The DAC will still be used for both audio and video. The sync combination and RGB amp on the RaspberryJAMMA will be bypassed by plugging the VGA cable directly into the DAC (and there will be no video signal at the JAMMA edge in this configuration) however the rest of the setup remains the same. You will need to cut the cable tie holding the DAC on the RaspberryJAMMA to remove it. It should look something like this mockup I did for you:

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strider88
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Re: VGA monitor set-up

Post by strider88 » Fri Jun 08, 2018 5:05 pm

Perfect! this is exactly the information I was looking for. Thank you for posting the pictures, very helpful.

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Re: VGA monitor set-up

Post by strider88 » Mon Jun 11, 2018 10:06 pm

got it all set-up and it works great. Thanks!

Does the audio output sounds any better coming out of external speakers or will the quality be the same that I hear through the jamma pins. If so is it easy to use external speakers?

Thanks again great heardware!

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Re: VGA monitor set-up

Post by dee2eR » Tue Jun 12, 2018 2:13 am

Hard to say as it will come down to the individual speakers and external amp etc. If your cabs speaker and the mono amped JAMMA signal suit each other well they may sound better than a 2 channel external amped system (the opposite can also be true, it comes down to the hardware you have).

If you want to try external speakers you can get a line level stereo signal out of the DAC. By default the stereo signal out of the DAC is combined into mono and amplified on the RaspberryJAMMA, so if you are bypassing the JAMMA mono audio you will need a sepperate 2 channel amp. No software changesd will be necesary, the software runs in stereo and the hardware mixes it to mono so bypassing the JAMMA audio leaves you with stereo. Some cabs will already have an RCA style inputs for stereo sound which makes this very easy, otherwise some people use a 2.1 style PC speakers or similar. Personally I use the JAMMA mono audio, as it simplifies swapping boards.

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Re: VGA monitor set-up

Post by bkeez » Fri Oct 12, 2018 7:25 pm

This was very helpful!! While trying to connect using this setup, did you ever come across the error "No Cable"?

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Re: VGA monitor set-up

Post by triggerhappy » Fri Sep 18, 2020 1:10 am

Greetings,

Like the author of this thread, I recently ordered an ARpiCADE from highscoresaves.com (which I haven't received yet), and I have a related VGA question...

Presently, I use a Mike's Arcade Double JAMMA Adapter to switch between two PCBs: an ArcadeSD and a JROK Mylstar (Q*bert) board. The switch does not have its own on-board VGA connector, so the way I output video is by wiring the JAMMA pins for R, G, B, vertical sync, and GND from the switch to a VGA adapter (see: https://www.amazon.com/gp/product/B014L8ROKA).

My display is a 20" Dell LCD monitor, which does not support CGA resolution. This is not an issue, however, because both the ArcadeSD and JROK boards have physical jumpers for VGA output, which enable video to display successfully via my JAMMA pin-to-VGA setup.

My intention is to replace the ArcadeSD with the ARpiCADE, while maintaining the JAMMA adapter which allows me to switch to my Mylstar PCB. So my question is: will I be able to route VGA-resolution video through the JAMMA pins to my monitor from the ARpiCADE?

Thanks in advance for your help!

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Re: VGA monitor set-up

Post by dee2eR » Fri Sep 18, 2020 4:12 am

Good question.

It should work, but I haven't tried it. As long as you have the ARpiCADE software set up for VGA it will be sending 480p to the JAMMA edge when the DAC is plugged into the RaspberryJAMMA so there's no reason it shouldn't work if your setup will work with RGBs (composite sync).

The JAMMA edge video RGB are also amplified on the RaspberryJAMMA, I imagine it is the same on the other boards too but am not sure in VGA mode- it's possible the brightness may be different from board to board.

If you absolutely need to use the vertical sync only some fiddling/modding will possibly be needed.

I'll be interested to hear how you go.

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