The final production Retro Adapter PCBs arrived yesterday. I made one up and it works perfectly. I am very happy with the world Seeed Studio did on them, especially considering they are cheap and accept files in Eagle format (so they do all the conversion or Gerber and any panelization etc).
I will put together a complete assembly guide with photos at some point in the next week or two, as well as releasing V1.0 of the firmware complete with USB update facility. I am still considering options for the update facility as it needs to be triggered somehow. At the moment the best option looks like holding a fire button on the controller, but the problem is that due to very limited space in the bootloader section it will have to be a simple controller like an Atari/Amiga joystick, Neo Geo joystick/pad or maybe a Sega Saturn pad. In case you don’t have one, a very simple update “plug” made from a DB9 and 1 wire to simulate the fire button being held could be used.
With a bit of luck the Retro Adapter will be on sale soon in time for xmas :-)