The GGG Red-board to Dupont pins cable will work with the Ultimate I/O board if you extract the ground pin from the housing since the 5v and ground pins are not next to each other on that board.
Sorry I’m still a little confused by that statement.
Are you saying the Happ Trackball will pin into the Ultimarc Ultimate, but I will need to remove the ground pin from the quick connect since it won’t fit?
If you look at the trackball Dupont pins on the Ultimate I/O board (top, just left of center), the ground pins (G) are on the left, the data pins (X1/X2, Y1/Y2) are in the middle, and the 5v pins are on the right.
If you look at the picture of the GGG Trackball Cable for Opti-Wiz™ "No-Solder", one of the 1x2 black Dupont pin housings has 5v (red wires) and ground (black wires) next to each other.
To make the GGG trackball cable work with the Ultimate I/O board, you'll need to pull one of those two pins (I recommend ground) out of that 1x2 housing using
this procedure.
If you have a spare 1x1 or 1x2 Dupont housing, you can put it on the extracted pin
or you an just plug the bare pin directly onto the Ultimate I/O board.
Plug the one ground pin on the left, the four data pins in the center, and the one 5v pin on the right.
Scott