In the real world, you can't drive a car or steer a bike with a joystick and buttons, and the same holds true for some of the best games ever made. Games that put the player in the driver's seat of a racecar or spaceship, or riding a motorcycle or bicycle. These games need specialized controls, like steering wheels, pedals, shifters, and handlebars. If you feel the need for speed, you'll likely also need some of the following:
While steering wheels come in all shapes and sizes, there are two basic types once you get under the control panel: Optical and Analog.
Optical (360 degree wheels)
Optical wheels spin freely, all the way around, as many turns as you like. (With one notable exception, that is- see "Roadblasters" below.) The electronics consist of an optical encoder wheel that spins through two infrared emitter/receiver pairs. If that sounds like the description of a spinner, that's because an optical wheel really is a spinner with a big steering wheel in place of the knob. These connect through the same hardware as a spinner, too- a Mouse Hack, Opti-Pac, Opti-Wiz, or similar.
Games that used Optical wheels include:
- Pole Position
- Championship Sprint
- Ivan Stewart's Super Off-Road
- and many more...
Roadblasters is an interesting exception to the rule. Roadblasters used a unique optical controller that was limited to 270 degrees of travel. The Roadblasters controller can be interfaced the same way as any other optical wheel, but cannot be used to play any other optical wheel games because of the limited travel. (The Roadblasters controller also pops up in discussion of Flight Yokes, see below.)
Analog (270 degree wheels)
Analog wheels do not turn freely throughout the full 360 degrees of the circle. Analog wheels have a limited range of motion - typically described as 270 degrees. Though, in reality, the actual number of degrees varies from controller to controller. The shape of these controllers varies as well. Since the control doesn't spin all the way around, there's no need for it to be a circular wheel. Likewise, since the control doesn't spin, wires can be run into the controller without fear of twisting and breakage. The arcade manufacturers took advantage of this by adding buttons, triggers and the like to these controllers. The electronics consist of a simple potentiometer (plus switches for any buttons or triggers). Like other potentiometer-based devices (see Analog Joysticks), Analog wheels interface through a Dual Strike hack, AKI, A-Pac, or other similar device.
Games that used Analog wheels include:
- Spy Hunter
- Out Run
- Power Drift
- Road Riot 4wd
- Hard Drivin'
- and many more...
While most analog wheels turn about 270 degrees, some of them were closer to real car steering, with a limit of about 1080 degrees, or three full turns. Hard Drivin' was the first arcade game to have such a wheel. The full range of degrees typically run from 255 degrees to 285 degrees, and from 900 degrees to 1080 degrees, but all electronically the same with analog POTs.
Some games gave the player more than just a steering wheel- they gave you a yoke. The primary example, of course, is Star Wars, though that's not the only one- see list below. The yoke consists of a set of handles that can be rotated forward and back, as well as turning right and left. Thumb buttons and triggers are also standard. The electronics consist of two potentiometers- one for the right-to-left (X-Axis) movement, and one for the forward-and-back (Y-Axis) movement. As with other potentiometer-based controllers, these are interfaced through a Dual Strike hack, A-Pac, AKI or similar. Electronically, a yoke is identical to an analog joystick, and indeed, you can use a yoke to play analog joystick games, and vice-versa.
Games that used a yoke include:
- Star Wars
- The Empire Strikes Back
- Return of the Jedi
- Turbo Sub
- S.T.U.N. Runner
- Apache 3
- Star Fire
There are also quite a few controllers out there that look like yokes, or even work like yokes, but are for one reason or another, just not quite yokes.
- Starship One: This flight controller turns right to left, and pulls/pushes in/out, rather than the handles twisting back and forth. You could call it a yoke, but you probably wouldn't want to try aiming in Star Wars by pushing and pulling!
- Paperboy: These bike handlebars turn right to left, and also push forward and back. Again, you could call it a yoke, but it probably wouldn't play very well with true yoke games.
- Enduro Racer: These motorcycle handlebars turn right to left, and can also be pulled back, much the same as you'd do when popping a wheelie on a bicycle. It's got both X and Y axis control, but the Y axis would be awfully difficult to use in aiming X-Wing lasers.
- Roadblasters: This controller looks very much like a Star Wars yoke, to the point that early versions actually had the same metal handgrips, thumb buttons and triggers. Two things keep Roadblasters from being a yoke: The handgrips don't move, so there's no Y-axis control; and the electronics are actually optical in nature, rather than potentiometer based. Determined users have converted these, but it requires considerable new parts, engineering, and metalwork.
- Road Riot 4WD: This controller looks like it might be a yoke at first glance, but the handles don't move, so there's no Y-axis control. This is really just a 270 degree analog steering controller.
- Spy Hunter: With handgrips sporting both triggers and thumb buttons on both sides, the Spy Hunter wheel could be a yoke, if only it had forward/back movement. It doesn't, though.
Who ever saw a bicycle with a steering wheel? Well, OK, one kid at my school had one, but that was the exception that proves the rule. Motorcycle and bicycle games wouldn't be right without a set of handlebars. In general, handlebars are the same, electronically speaking, as Analog steering wheels. They use a potentiometer to measure left/right travel, and interface through an A-Pac, AKI, or Dual Strike Hack. Some handlebars include buttons, brake levers, twistable throttle grips, and even forward-to-back motion (Paperboy and Enduro Racer).
Games that used handlebars include:
- Super Hang-On
- Enduro Racer
- Wild Riders
- and many more...
Gas, brake, and clutch- you can't drive a car without pedals. Some games used just one for gas, some add a brake, and a few used all three. There are two basic types of pedals:
Analog pedals use a potentiometer to determine how far the pedal is being pushed, and therefore can tell the game how much gas to use, or how hard to brake. Analog pedals interface through an AKI, A-Pac, or Dual Strike hack.
Digital pedals are simply "on" or "off". Games that used digital pedals cannot tell how much gas or brake you are using, it's all or nothing. Basically a button for the foot.
Some driving games, you just pushed down the pedal and went. Others looked for more realism, and added a high/low gear shifter. Other games took it further, with 3, 4, or more gears. Some shifters also included a "Turbo" button on the handle.
Constant-press vs. Momentary-press
Different shifters report their position to the game differently. Some push a switch constantly for each gear, while others only close a switch momentarily. Many use a position where no switch is closed to indicate one of the gears, or neutral.
How MAME handles shifter inputs
MAME's handling of these different types of shifters is even more unpredictable. Some games use momentary switches, some use constant. Some games use the same method that the original controls used for that game; some do not. Some control schemes can be re-mapped to make use of a different shifter type, and some cannot.
What's it mean to me?
What this means is that no one shifter will play every game in MAME. If you're planning on incorporating a shifter, you will need to do considerable research into the requirements of the games most important to you in order to determine the type of shifter you will need.