IO board for Atari 800 Sophia 2

Avoiding cutting holes in a vintage computer with this one. Excellent quality board thanks! I'm revising this because I did not check the stereo jack footprint carefully enough. It couldn't get much simpler, all the routing is one sided but keeping it to the space available in the Atari 800 power supply area that is available after removing the obsolete RF modulator and moving a couple of capacitors was slightly challenging. I have soldered one up and found that the HDMI to 12-way connector is correct so did not need to change much but have taken the opportunity to make the HDMI differential traces better aligned and surrounded by more ground plane.