After wanting a game on Guilty Gear Isuka but not having a cabinet with the correct setup for it (Ok Baby and Blast City monitors are rotated, Astro City doesn't have a 5 button loom), I decided to remedy that by making myself a 5 button Sega loom. By default these things usually come set up for 3 buttons, sometimes 4. For most games this is enough, the only exception I can think of from the top of my head is the Atomiswave and some of the games on that. Unfortunately Guilty Gear Isuka resides on the Atomiswave. I ordered the connector and pins from Digi Key, and used some 18 AWG wire and some 2.8mm crimp terminals I had lying around. It's not necessary to use 18 AWG wire, 20 or even 22 would do the job just fine, but the thicker the wire the better generally speaking, and I have plenty of 18 AWG.
Once you have the parts it's a straightforward process. Connect the wires to the connector pins (they crimp but I add a little solder to secure it), push the pins into the connector, then add the crimp terminals (again I add a little solder to hold the wire into the terminal as well as crimp it. The only slightly tricky part is the ground wires. The ground comes from one pin, and has to be daisy chained. The only thing you need to really be sure of is that there is a good connection between the wires on all of the grounds.
Here's the end product:
If you wish to give this a go yourself, the pinout can be found on the Arcade Otaku wiki here:
http://wiki.arcadeotaku.com/w/Sega_Naomi_Universal
