As previously mentioned, I had planned to wire harness with a JAMMA edge like this:
@LemonyVengeance gave me the idea of bypassing the JAMMA edge and just wire it directly to the Blast City I/O.
Due to the sheer amount of wire I needed, I figured it would be cheaper to bastardise an old original Blast City harness that I got for 30 dollars (not the one the Sega 001 loom, but an original Blast City one). I also had a whole heap of JVS power harnesses laying around and other bits and bobs I could use.
I removed pins that I didn’t require from the harness – I only needed, P1 and P2 Up, Down, Left, Right, Start, B1 and B2, test, service, coin, coin meter.
I know it’s not a pretty sight to hack up original harnesses, especially those Hirose JAMMA edge, but I promise, this is for the greater good
With the new harness, meant new colour coding, so I updated the spreadsheet with the colours. I get crap for having spreadsheets from family and friends all the time, but I’m telling you, if I didn’t have this spreadsheet, I would’ve had heaps of issues.
My updated schematics
The main wiring (P1 and P2 buttons – no lamp/power) was completed after a solid couple of hours, was checked and double checked for continuity to make sure everything was in its proper position
I started working on the lamp and power harness but I didn’t realise that the connector for that was 20 way! I only had a 26 way! FMD *face palm*. I ordered a 20 way, but I was determined to get this done so I hacked up the 26 way and turned it into a 20 way but cutting the last holes and the tab on the connector as the JST RA is keyed.
The harness is now complete! Also added the stereo RCA’s. This OG harness has essentially been turned into a Sega 001 loom plus the requirements for LEDs to light up according to the game code.
Here’s the big test!
All wired up to a Sega type 3 JVS I/O if LED buttons are to be used, otherwise, I could’ve just used the normal Sega JAMMA to JVS I/O or the I/O found in a NNC (Sega type 1 JVS)
The first power on was the most nerve wracking as there’s always doubt with these things, I’m always scared I wire 12v up where 5v goes, it also doesn’t help Sega doesn’t use “standard” colours like those found in an ATX PSU ie. 5v = red, 12v = yellow. Sega uses Yellow for 5v and red for 12v! You can see where people would mix this up and fry pcbs.
Needless to say, I was VERY happy when I turned the cab on, loaded the game and there was no smoke and the buttons and LEDs worked!
Quick video of it working