Actually that still doesn't answer my question - I already know what the DSATX side of the Brainstem pinout is - I need the serial side of it.
HOWEVER, that link you posted has an item that will work for what I need - I needed an extension cable as I can't plug in the Brainstem in the DSATX and have a serial cable plugged into it as well (due to my layout). My idea was I would just extend the serial portion from the Brainstem using whatever wires I needed but this extension cable does exactly what I need so I thank you for that find.