NAOMI Type-X Mahjong pinout.

Hi y’all,

I first set up NAOMI to play in a Mahjong cab in January-February 2008.

Here is Suchie Pai III running in my Astro City.

Oh, and here I am exhibiting my 1337 sKillZ

Unfortunately the site on which I posted the details has vanished off into the cosmic void, as has the second site that I re-posted on. Now that I have dusted off my Taito Type-X¹ motherboard and Hot Gimmick 5 I thought it was about time to do the write-up again somewhere it could easily be found 😀

The main issues I had when I set up the NAOMI system were that I had no clue as to how to set up a “normal” NAMOI system and that setting up with a Mahjong control panel had apparently not been documented by anyone in English. So trying to separate out Mahjong specific issues was difficult. ❓

In the end, the Mahjong control panel was very simple to attach and get working. In order to make the information posted here as simple as possible, I assume that the user knows how to get Type-X¹ and/or NAOMI hardware running.

Put simply, the Mahjong CP is connected to the Type-X¹ via a REV. B SEGA JAMMA I/O. The multiplexed inputs are connected via pins 17-22 on the parts side of the JAMMA loom and pins 4-8 on CN3 in the I/O. I have created an updated spreadsheet for Type-X¹/NAOMI multiplex from the one I did previously. Here it is:-


  • The colours and numbers in square brackets [1] above represent the wire colour and connection number on the Mahjong CP.
  • Jumper JP1 in the middle of the I/O should be set to ‘B’
  • Do not plug any power connections into CN6 if you take power from the JAMMA loom.
  • To avoid altering the JAMMA loom in my cab I had this made:

    As my understanding of the project improved, I removed the Grounds as they were not required and I also removed the connector as I misunderstood where the connections were to go. Finally, the friend who did the above work suggested using a cable from an LS joystick and shaving the sides off so it would go on.

    I then crimped pins to the ends of both sets of CP wires and connected to my Mahjong CP.

    Finally, as you can see from the above picture, I had the connectors from my sound amp soldered to Pins 10 & L on my loom insert.

    You can run Player 1 Sound from the bottom 3.5mm socket at the back of the PC to speakers without an amp. Player 2 sound comes from the middle 3.5mm socket.



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