Using the 4 slot MVS with a supergun: a quick article on my findings using both the Retro Electronic Pro Gamer supergun and the Mini Gun Supergun (an open source supergun).
Because the jamma standard differs from the multi slot neo geo pinout there has been some confusion as to whether or not a “mvs to Jamma” adapter needs to be used with a supergun. While it will work and possibly simplify the playing experience I’ve found it to not be necessary with either one of these guns.
I’ve found that both superguns will run the multislot MVS safely and properly (both sound and video) with no need for the MVS to Jamma adapter. Both guns have some pros and cons though. While neither is 100% right out of the gate I’ve found that with minor adjustments each one can run flawlessly. Before turning on make sure to set them to stereo. And with the Retro Electronik make sure it is set to standard jamma pinout. More info on these settings below.
Note that the multislot mvs has its own joystick ports on the rear. When plugged into this the select button cycles through the games but there is no way to insert a credit. You either have to press the coin button directly on the supergun pcb or set the hard dip settings to free play. If only one game is inserted in the MVS and “input crossings” is enabled (it is normally by default) in the unibios then the select button from the MVS will insert coins instead of cycle through games. This will not work if multiple games are inserted.
The Retro Electronik supergun is perfectly compatible with the Multislot Neo Geo. When plugged into the supergun’s db15 port the Select button on the joystick is properly mapped to the select button on the mvs (unlike the minigun). It perfectly mimics if you just plugged your joystick directly into the MVS’ rear joystick ports.
Make sure to push IN the mono/stereo push button to make sure it outputs stereo. Also make sure the “button mode” is OUT meaning it is set to standard jamma pinout. You DO NOT want to set it for the blue elf/ Pandora’s box setting.
The only downside with using this supergun is you can’t add credits directly from the joystick. You have to press the credit 1, credit 2 or service button directly on the supergun pcb. Work arounds: you can wire a jumper from the credit one terminal block to player 1 button 5. This will allow select to also insert a coin. (Note that this will also cycle through the available games if in attract mode.). Another work around is to change the hard dip switch 7 to ON for free play.
While testing I’ve found the sound is slightly lower on the RE supergun compared to the minigun. Either raise the volume slider directly on the MVS pcb or raise the tv volume as a work around. (This is because using stereo divides the output watts. Same as if I put a regular mono jamma game into stereo mode- it works but the volume gets much lower compared to keeping it in mono.)
Lastly a note on the TEST button with the Retro Electronik. For some reason the test button WORKS on this super gun. This is puzzling because if you compare the pinouts the normal jamma test button should get remapped to “coin switch player 3” on the mvs multislot pinout. (And this is exactly what happens with the minigun.). But for some reason the RE supergun corrects this pinout issue and it works with no problem.
The player 1 coin button gets mapped directly to the select button on the joystick with this supergun. Meaning if you plug your joystick directly into the supergun you will NOT cycle through the available cartridge slots when hitting select. You will only insert a coin. (Note that If you keep hitting the D button it will eventually skip you to the next game.) This may also be a problem for playing in Console mode if a select button is ever needed. Work arounds for this are: using a unibios enable “cabinet fixes” option. This option then allows buttons “A” and “B” to cycle forward and backwards through the games. However it won’t fix the issue if you ever needed the select button in console mode. Another work around (if you didn’t have a unibios) is to plug the joystick directly into the MVS joystick input. This will allow the select button to function properly but coins will have to then be added by pressing the service button (or test button see below) directly on the supergun pcb. Another option would be to flip hard dip switch 7 to ON for free play.
When hooked up to the multislot Neo Geo the test button on the mini gun’s pcb acts as a player 3 coin input with this supergun. (Note the test button functions properly with any standard jamma game or even the single slot MVS) This is because of a difference in the jamma pinout between standard jamma and MVS pinout. This is a problem as there is no way to easily access the test menu to adjust the soft dips for each game. This is the only major downside of using the minigun directly hooked up without the MVS to Jamma adapter (which has a test button directly on its pcb). Work around: set hard dip switch #1 to ON. This will boot the MVS into test mode. Make your soft dip adjustments and then switch it back to OFF to boot back to the games.
Also don’t forget to move the jumper from mono to stereo on the minigun itself to make sure you get stereo sound.
Overall both superguns will work great with the multi slot. The “mvs to Jamma” adapter really only needs to be used if legitimately plugging the multi slot into a real jamma arcade cabinet.
For more info on the Retro Electronic Pro Gamer Supergun check out:
For more info on the open source Mini Gun Supergun project head over to: