My supergun pcb design


#1

Hey tech talk, long time lurker here. Long story short, I wanted to relive some of my highschool days with xmen vs street fighter and I didnt want to bother with getting the saturn version. I always wanted to start collecting arcade boards, so I decided to go the supergun route. Most purchasable superguns seem to be of varying qualities of homebrew anyway, so why not make my own?

The first draft was made using cadsoft’s free version of Eagle. There is a 100mm board length limit, but since jamma pads 1,2,A,B,27,28,E,F are all ground, I can have the pcb in the middle and connect the grounds to the copper pour. I also wanted this board to be pretty straight forward and simple in design. This board has:

[list]
[] 8pin mini DIN for video out
[
] RCA audio jacks
[] stereo/mono audio switch
[
] audio attenuation circuit (jasenscustoms design)
[] atx 20 pin power port
[
] DB15 neogeo style controller ports
[] pin holes for all the jamma pads
[
] jamma and multicart (elf/pandora) button support switch
[/list]

imgur.com/a/9KiKl

I do want to add fuses to the 5V and 12V lines and possibly add the audio to the 8pin minidin? If and when I get around to doing a new version, I have a list of additional features to tackle

[list]
[] KiCAD board design, to get full length jamma pcb
[
] Voltage display and tweaker
[] RGB video tuning
[
] Video encoder for more options for video output?
[*] scan line generator?
[/list]


#2

Keep in mind some arcade boards, mostly older models also need -5 volts.
Most PC Power Supplies did away with the -5 volts, keeping only +5, +12, -12 and +3.3 volts.
Arcade power Supplies do supply that -5 volts.

Good idea adding fuses and the Voltage display and tweaker.

For audio, you might want a 4 pin JSX connector for some Neo Geo and Konami boards to pick up their stereo audio.
You want to consider a connector for Kick harnesses. Many Fighting games have a additional harness for the extra 3 button inputs.
Also want to read up and understand the differences between regular Jamma and Neo Geo variants in the Jamma pinout.

For your RGB video attenuation I would go with external Pots to adjust on each video line.

As for you Video encoder/converter. What kind of Display are you using? What Video format?
Your Scan Line Generation will fall in with what converter you are using.


#3

Im thinking of using a picopsu, so i dont have a powersupply just hanging out on the floor. My main concern is getting CPS1/2 games working, older games and neogeo would probably be something that comes in the next revision. As for the kick harness, I was thinking of just soldering in the kick harness wires for K1,K2,K3 for p1 and p2 where the pin header holes are, and have it attached all the time.

My samsung tv does have a scart input and I heard some people have had success with 15kHz signal video playing on samsung tv’s. Im also planning on getting a GBS8200 board for vga output. I would love to take the RGBs from the jamma pins feed it into a CXA1645/LM1881 combo and upscale it to 31kHz for proper vga out on my own.


#4

For about a few bucks more you can get a power supply intended for arcade mother boards.

GBS8200 board gets the job done, but just so. it was intended for Arcade owners and operators to have a cheap alternative to use older arcade boards with 31khz VGA monitors.
You need to come up with some custom cabling to use it with your Arcade board, you might also need a sync cleaner

As for a Scan line generator the SLG Mini does the job pretty well.


#5

Would you consider putting it up on github so others can contribute, or are you making this in hopes of selling them?


#6

I only say because you and I are working on a similar design - only mine would be hooked to an xrgb-mini, and I’m trying to make something I can cheaply crank out and “tie” to an arcade board to permanently consolize it, while maintaining jamma/kick harness capability.

I wish you the best of luck with that SCART input, but modern TVs really don’t want to sync that low. Just a word of precaution.


#7

But the awesome thing about PicoPSUs is that they’re tiny! :smiley:
Much easier to fit in a smaller enclosure.


#8

I was thinking of throwing it up on github, but I want to test it out and make sure its working first. Just in case some one makes one thinking that its a tested and working product. I just sent it out to OSHpark to get fabricated, so we will see in a few weeks how well it all works. And yeah I dont have high hopes that my tv will work with that 15kHz rgbs signal, but i can fall back on getting a GBS8200/Clone that can upscale to vga if not.


#9

NVM