It used to be button 10 (also counting 4 scrollwheel directions and click) of my Elecom trackball. I had written a small C program reading the device node and writing the events just of that to stdout, then piping that to a tclsh script (so I could change it easily and it’s still super fast for gaming) which did something in X. Horrible.
But then they added support for more buttons to everything (kernel, X) and now I can just map it in games, like any other.
It used to be button 10 (also counting 4 scrollwheel directions and click) of my Elecom trackball. I had written a small C program reading the device node and writing the events just of that to stdout, then piping that to a tclsh script (so I could change it easily and it’s still super fast for gaming) which did something in X. Horrible. But then they added support for more buttons to everything (kernel, X) and now I can just map it in games, like any other.