I posted a write-up about making 3-4 Player Supergun harnesses for Konami arcade game PCBs like TMNT, X-Men, Sunset Riders, etc. I also show how to make stereo audio leads for them. However, if you own a Home Arcade Systems “HAS” Supergun, you can simply add-on the 3-4 player adapter board and a Konami harness. That’s much simpler 😀
Konami 3-4 Player DB-15 Controller Harness
Konami Stereo Audio Lead & JST-XH Jack Upgrade (Sunset Riders pictured)