What is a supergun? According to Bobak, creator of the Neo-Geo.com Glossary:
A Super Gun is a mini-arcade system, usually used for home use on a television (like a home console system). Essentially, a supergun contains the insides of a standard arcade videogame cabinet shoved into one neat little box. There are several different "brand name" Super Guns out there, including the MAS SuperNova, and the GW HGA (see separate listings). People with technical expertise have created their own superguns. Essentially it plugs in a JAMMA board and some controllers and gives the user the ability to plug it into a TV. An option for a person who wants the cheaper games via MVS, but does not want to spring for a full-size cabinet. Also known as a 'JAMMA Test Rig.'
Basically, a SuperGun allows you to play arcade PCBs on your TV through Component, S-Video, or composite video (unless you're one of them Euro types with RGB/SCART). Imagine playing an original R-Type board on your TV! There are many ways to outfit your SuperGun, especially as far as the JAMMA connection goes. Neo-Geo MVS format is fairly standard and uses 4 buttons, while many Capcom games like Street Fighter use 6 buttons. The good news is, generally, all you'll need is one SuperGun JAMMA set-up and you'll be able to play many boards available out there. Another consideration is the type of voltage required for your arcade board. Most boards use +5V, some use +12V, but a handful use -5V too, usually for things like audio amplification or coin counters or whatnot.
I make my SuperGuns to be fully Neo Geo compatible, to play most JAMMA boards, and to use the standard Neo-Geo 15 pin controllers. Most standard JAMMA boards will play on these. If you are curious if the board you are interested in buying is JAMMA, check under "Conversion Class" for that title at www.klov.com, a fantastic resource for arcade gaming.
Got ideas for a SuperGun? Let me know!