Pinouts aren't hard to figure out with a volt meter.

We know where +5 and ground are because almost all EPROMs have +5 on the upper right pin (notch facing up) and ground on the lower left pin, so we use our volt meter on the ohms setting to find the pins on the edge connector with close to 0 resistance to those pins on an EPROM. +5 and ground is enough to power 90% of the boards out there.

Next we need to find video. First, connect video ground to any ground and turn the power on. Then take the composite sync wire and run it along the remaining pins until you get raster. It's safe to run it along any pins we like at this point because all we have hooked up right now is ground and +5, both of which are safe to touch with the sync wire. Even with no colors hooked up, you can tell when you find sync because you'll get solid black raster, which is different from no raster. You'll know. Next we need some color. Green video is almost always right next to sync, so try touching the green video wire to the pin left of or right of the sync. If you get a green picture, swell. Otherwise, keep touching pins until you get a green picture. Once you've found it, red and blue are sure to be near by. Usually red is on the opposite side of green and blue is opposite sync. Try those first, if not, it's usually red, green, blue all in a row, so try either side of the green video. Now we have power and video. If the picture colors look wrong (red skies and blue explosions), try swapping around the colors until things look right.

Next we need sound and control/inputs. Sound amps almost always need +12 for power. Power traces are usually thicker than inputs and video, so we look for a thick trace that goes over to the audio amp section of the board. Speaker + and - are usually right next to the power. Be careful not to connect +12 to one of the speaker lines. You'll either pop a cap or smoke your power supply depending on what you hook up to. If the part number on the amp is readable, it's usually pretty easy to find the pinouts for the amp on the internet and double check your suspects that way.

Next is inputs. This is pretty easy. Just take a wire, hold one end to ground and run the other end along the remaining pins, being carefull to avoid the power pins, until you get a credit. That'll be either coin 1 or coin 2. Repeat until you get another credit on a different pin (which will be the other coin input or the service switch) or until the game starts. Make note whether it started a 1 or 2 player game so you'll know which it was. Power down and repeat to find the other start pin. Once a game is started, just repeat to find up, down, left, right, fire, jump, or whatever else there is.

Some boards need -5 to power audio or if the board has 4116 RAM chips, they need -5 volts, too. -5 is on pin 1 of of 4116's (upper left pin, notch facing up), so use your ohm meter to find the -5 pin on the edge connector.

If -5 is sometimes used for audio like on some Konami games, but most Konami game pinouts are listed on www.spies.com/arcade, so go check there. =)

Tim tim@arcadecollecting.com