Please add an option to allow the configuration of the joystick dead center.
Some analog joysticks have slightly off center values, and when the currently value is to sensitive for some of my joysticks, resulting that there's always some direction being pressed for the emulated MSX.
It doesn't need to be complex. Just something like:
set joystick1_deadcenter = 20
This would set up a dead center of -20/+20 for both X/Y axes from joystick1.