During my journey to perform an RGB mod to a TV for my arcade machine [here], I found that I had to add multiple features to make it work, and so I converted the breadboard design into a customized PCB that will handle most needs for RGB modders for both console and arcade users.

 

Is this board really necessary? Not really as much of the work can be covered by a few wires and components to an existing TV. As a result, for simpler mods, I would not necessarily recommend this board, although you could consider using the "mini" version of this universal board for simpler console + TV applications (see below for a sample installation).

 

For more complex mods that might require managing the sync signal, adding an auto-start feature, or to have the ability to adjust color levels, then this board may be useful and a time saver, particularly for arcade users.

 

Here are early renders of the full standard board and mini board.

 

 

 

 

 

 

For the arcade users, here are additional renders of various remote buttons that can be installed in the coin door for the Williams arcade machines (top) as well as left-handed and right-handed generic remotes.

 

The design goals for this universal RGB board are:

 

 

 

SECTION 1 - How to obtain this board

 

All design files, drawings, etc. to have your own board manufactured are located  [here]. ** COMING MARCH 2022 **

 

As a one-time opportunity, I ordered a few spares so you can purchase this board with or without components [here] ** COMING MARCH 2022 **. If it is no longer available, you can still download the files, and then upload the manufacturing zip file (included in the download) to the PCB manufacturer of your choice.

 

Note: because there are many choices to be made such as resistor values, diodes (yes or no), capacitors (yes or no), positive or negative sync, this board is not available with the components pre-populated. Therefore this is for people who are comfortable with soldering. To make things easier, there are no surface mounted components, and the soldering pads are relatively large to ease soldering.

 

SECTION 2 - Assembly Instructions

 

The zip file download includes instructions to decide which components to install, which ones to skip, and which ones to bypass, and how/where to install the board. You can also view these instructions [here]. ** COMING MARCH 2022 **

 

SECTION 3 - General thoughts on SCART and VGA inputs

 

If you are looking at a SCART option to use with this universal board design, look for space to mount the board inside the TV and connect the RGBC ports of the board to remote RCA or BNC jacks or to a SCART plug on the TV back panel.  An example of remote ports on a TV is shown [here]. Note: these pics are not of my board, but installation would be similar.

 

 

Afterwards, you should be able to use a standard SCART-to-RCA (or BNC) cable adapter. Important: I have not tested this scenario, and I currently do not plan to. Board shown in picture is not this universal board, but concept is identical

 

• Optional SCART 15 kHz support through a SCART-to-RCA RGBS cable adapter, with the "S" (Sync) output being the Composite Sync (not tested, so proceed at your own risk). Note, you might be better served to build your own, but this adapter on ebay seems to be the correct one [here]
• Optional VGA 15 kHz support through a VGA-to-RCA RGBHV cable adapter (tested and it worked)
  • ebay - option #1 with male RCA jacks [here] - hard to find anywhere. This is the last one on ebay.
  • ebay - option #2 with female RCA jacks [here] - easier to find, but need adapters [here]
  • ebay - option #3 with BNC jacks [here] and comes with proper adapters
  • Ebay - option #4 with BNC jacks [here] - easy to find, and you can select a cable length that makes sense for your installation, but need adapters like these [here]
• Optional VGA 15 kHz support through an  [Extron 192 on ebay] adapter (tested and works, but I had some light noise on the display which might have been from the cables I used)
• Optional VGA 31 kHz support through a [GBS-8200 Open Source Mod] downscaler (not tested, but I plan to test this eventually)

 

 

SECTION 4 - Thoughts on using a Raspberry Pi or a PC

 

Note:

• Tested with a Raspberry Pi3B+ with Retroarch using an older Lakka v232 download
• Not tested using a PC, but there is plenty of material on putting out 240p via older ATI graphics cards

 

• Equipment used
  • Rasberry Pi 3B+ with a good power supply
  • an HDMI-to-VGA adapter (whatever was available on Amazon)
  • Lakka's official Retroarch distro for the Raspberry Pi
    • I used an older Lakka v232, but newer versions should work as well or better
  • Setting the Raspberry Pi output to 240p
    • I followed the instructions given in this post [here]
    • I had to do multiple tweaks (which are above and beyond the intent of this post), but I posted my process on this forum, but the key discovery is that my widescreen Dell monitor U3415W works at 15kHz, so I was able to test all the settings at my desk.
    • Alternatively, you can use a device to convert the 31kHz VGA output to 15kHz downscaler such as a  GBS8200/8220 (see link above)

 

 

• Here are the results of the Raspberry Pi test (see the post [here] for pictures):
  • It worked fine with no issues with the prototype board.
  • Tested with VGA output through an Extron 192 to combine HV into a negative C Sync
    • The Extron is needed if using the "mini" board because it is missing the HV to Composite combiner circuit.
    • Had some very light noise in the image - possibly due to bad cables?
  • Also tested with a direct VGA-to-RGBHV cable straight into the board, and the results were outstanding with zero noise whatsoever.

 

 

SECTION 5 - Thoughts on using a JROK arcade board

 

You have two options for using the JROK board with a TV CRT and the standard universal adapter board:

 

1. Option 1: Use the arcade output 7 pin MOLEX to the universal's board 7/10 pin MOLEX (or make an adapter cable to plug into the RCA jacks)
   1. Recommended as it is a far simpler installation
   2. This is what I tested, and it worked great

 

2. Option 2: Use the VGA output of the JROK at 31 kHz, run it through a downscale converter to bring the signal down to 15 kHz, and then into the universal board, either through the RCA plugs or through the MOLEX connector
   1. Not tested.
   2. There are multiple 31 to 15 kHz converters out there, and I will not test those except for the [GBS-8200 Open Source Mod]  which I will test when I get mine, and modify it accordingly.

 

 

And finally, I also realize that there was another attempt at a similar board that also used an amplifier for muxing [here]. That board utilized surface-mounted components, and is another smaller solution that can be considered for your application.