So you want to use a light gun on MiSTer but you’re not sure what you need. Let me help you decide :)
The GunCon2 sync breakout board requires csync from an analog IO board or similar. The other HD15/VGA port can either pass through video or be left disconnected. GunCon2 requires a 15kHz CRT.
Configure the MiSTer.ini settings according to your needs:
Is there a drawing of the board available so I can spec the spacing on the screw holes for a case?
I love light gun games and was ecstatic to see Mister Addons offer the IR emitters for the GunCon 3. After receiving them I set them up and put them to the test. I'm happy to say that they work great! I was able to use them on my MisterFPGA (note that you most likely will need to calibrate your gun which you can do by hitting F10 in the OSD) with the PlayStation core. My only regret was not buying two.