JAMMA stands for Japanese Arcade Machine Manufacturers Association and is the standard that the vast majority of game boards/cabinets will conform to. While this sounds like something really technical, that really couldn't be further from the truth! All JAMMA really is, is the order that connections are made to an arcade board.
Let's take a look at a normal JAMMA arcade board edge connector, in this case a Taito F3 motherboard. Now compare the edge connector with the pinouts... And you'll see how straightforward this really is!
So, let's look back over this short lesson... When we talk about a JAMMA connector we are referring to a wiring loom that provides power to the necessary pins on the arcade board. It also connects the Red/Green/Blue/Sync/Video Ground for the video signal, the speaker output and all the player inputs - its just a standard 28 way double sided edge connector (0.156" pitch) with a load of wire, but connected in a specific order.
Theres no need to make a supergun as such, you really can just join the dots and have a fully operational arcade game as long as you have a power supply, monitor/TV and controls. But of course, building a supergun makes everything nice and neat - after all you wouldn't have the innards of your Sony Playstation on display would you!?!!
One thing I will point out here but is covered in greater detail on a later page (Can I play games that aren't JAMMA?) is that nearly all non-JAMMA arcade games use the same voltages and inputs/outputs. Therefore they are still useable in your machine, but an adaptor needs to be built to connect the necessary pins to their correct locations. NOTE!!! That reads NEARLY all, there are some that use obscure voltages, negative video signals or a different type of monitor...