How to make a "jamma+" connector for Capcom CPS2

The jamma connector supports maximum 4 buttons (like in D&D). If you want to play SF or other 6 button games you have to do a bit of soldering. Its quite easy as you will see:

You find connectors for the additional buttons D, E and F on the "A-Board" (Main).
Connect like in the pic below:

And could look like this:

Have fun!