A600 Junior RGB to HDMI

The A600 Junior motherboard has some very useful improvements compared to the original Amiga 600 motherboard. One such improvement is a bunch of through-holes under where the RF modulator usually goes (and can indeed go, if you're that way inclined) that provide all the signals required by RGB to HDMI adaptor boards, and also 5V and GND for power:

The RGB signal through-holes are designed to take 2mm-pitch header pins, while the 5V and GND through holes accept the slightly larger 2.54mm-pitch pins, as you can see, here (credit: idoregesz.hu):

There is no universal standard for RGB to HDMI boards, so no adapter exists that you can just plug into the Junior's RGB pins.

I bought a basic RGB to HDMI board that looks something like this:

I then mapped out the flat flex connector pins on the Denise adapter board:

Now all I needed to do was get a PCB made that maps the Junior's RGB and power pins to these FPC connector pins. I went on easyeda.com and knocked up a simple design. A few days later, the PCBs arrived, and here's what I built:

And here it is installed:

The jumper wires are carrying the 5V and GND from the Junior to my adapter board, but it turns out that at this length they pick up interference that shows onscreen, especially with high-contrast graphics like white letters on a black background. Trimming the wires down to the shortest manageable length sorted out the interference.

At last, my A600 Junior has a pretty neat RGB to HDMI solution installed!

In case you want to try this yourself, here are some things that might be useful:

• Gerber file for the adapter PCB board
• FPC connector
• 16-position receptacle connector
• Very short flat flex cable to connect this adapter to RGB2HDMI board
• Adafruit mini-HDMI plug
• Adafruit full-size HDMI socket
• Short FFC for HDMI 
• HDMI socket mount

Note that the HDMI socket mount is not ideal for this purpose - a section of it needs to be cut out to fit around the Junior's RGB header pins. Also, the HDMI socket doesn't fit into the mount properly with this RGB adapter board in place - it's pushed out towards the back of the Amiga slightly. I'm planning another Junior build, and when I start that, I'll try to make my own modifications to the HDMI socket mount (originally by Teps71), specifically for the Junior.