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 composite sync 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. Both HD15 connectors are female, so plan on using a VGA cable between your MiSTer and this board, then another VGA cable from this board to your monitor.

Configure the MiSTer.ini settings according to your needs: