Joysticks
Conventional Joysticks
Conventional joysticks are fairly simple devices without which most Pac-Man would be ghost-fodder. When the joystick shaft is moved in any direction, the lower end of the stick is levered in the opposite direction and makes contact with switches, these switches are what tells Pac-Man to move.
By using four switches at the base of the joystick, 8 directions can be achieved; Up, Down, Left and Right as well as the four corner positions. Joysticks like this are known as 8-way.
Some games were designed to restrict the player from moving diagonally; for example, Pac-Man and Donkey Kong. Though it is possible to use an 8-way joystick for these games, it's not recommended, as accidentally hitting a diagonal with the joystick will cause Mario to stand still and Pac-Man won't know if he should go up or to the side.