In the days of DOS , every game using the game port ( s ) had to do its own calibration , often each time the game started , and some poorly coded calibration routines even failed to work consistently and properly , rendering some joysticks unusable with some games . In the days of DOS , each game using the game port ( s ) had to do its own calibration , often each time the game started , and some poorly coded calibration routines even failed to work consistently and properly , rendering some joysticks unusable with some games .