A D- or directional pad is a set of thumb-operated switches that provide 4- or 8-way directional input. Their common uses include character control in video games, and navigating menus on a variety of devices.
It’s generally agreed that D-pads evolved from arcade games that used four independent buttons arranged in a diamond pattern. The Intellivision also featured a disc-shaped control pad that provided 16-way directional input.
The modern D-pad, however, emerged in 1982 with the Game & Watch release of Donkey Kong, designed by Gunpei Yokoi.
The main design features that distinguished this D-pad from its precursors was that it consisted of a solid, cross-shaped piece of plastic with an internal pivot point. This gave it the crucial features of being self-righting with a short travel distance, and disallowing simultaneous left/right and up/down inputs.
The original D-pad patent, filed in 1985, describes Nintendo’s design as follows:
Basically, the whole d-pad is built on top of a plastic disc that tilts when a direction is pressed, which completes a circuit by pressing down one of four underlying membrane switches. When the pressure is released, that same membrane switch provides the returning force necessary to bring the disc back to its neutral position.
All d-pads in use today are a variation on this concept, with a variety of modifications.
Nintendo’s patent forced their competitors to work around several key aspects of their design, chief among them being the spherical fulcrum and the dish-shaped depression that it sat in, respectively labeled 13 and 21 in the figure below.
Early competing d-pads like those of the Sega Master System and PC Engine/TurboGrafx-16 managed to skate by with simply changing the shape of the upper pad, combining the lower disc and upper pad into a single unit, or leaving out the lower dish.
As time went on, efforts to avoid infringing on Nintendo’s patents became more sophisticated. For the original Genesis/Mega Drive controllers, Sega used a small ball that was disconnected from both the upper disc and the controller below, labeled 3 in the figure below.
With the Saturn controller, Sega enlarged the pivot point and turned it into a half-sphere again, essentially taking what Nintendo had initially devised and turning it inside out and upside down. This was also the emergence of the “piston” design, where the d-pad and the component used to depress the switches are actually two separate parts that connect vertically.
The design used in the Xbox Controller S and Xbox 360 controller are very similar in concept, though the usefulness of the latter is hampered by the lower portion of the pistol being extremely tall and the plastic “well” surrounding the upper disc being too restrictive.
Sony’s D-pad patents use a one-piece design, but designed in such a way they four faux-buttons appear on the surface of the controller.
Some of Sony’s patents incorporated an independent ball similar to Sega’s first-generation Genesis/Mega Drive controllers, as pictured below.
The ball was abandoned for an upward-facing rounded cone, as pictured below.
(PSX)
(PS2)
As my thread title implies, I thought we could use a thread dedicated to talking about these lovely little inputs devices. Talk about your favorite, criticize the ones you don't like, correct and expand on anything in this post, and generally discuss this topic in any way that doesn't involve calling people names for liking something you don't like.
Starter topic: Which of the above basic designs do you prefer and why?
