The Jammafier is a device that enables you to play older Jamma PCB’s in a JVS only cabinet, like the Sega Naomi Universal.  It handles controls, power and audio – but does not touch the video signals.  The intention is to address a few shortcomings of existing solutions, both technically and when it comes to availability – I hope you like it 🙂


  • Rapid JVS updates for minimal lag
  • Optimized layout for low voltage-drop
  • -5V generation
  • OLED display for diagnostics, including precision volt-meter for 5V and 12V
  • Attenuated audio via two RCA connectors for easy use with cabinet amplifier.
  • Raw video /sync, or 75-ohm video and processed sync via VGA connector*
  • Buttons 1-5 on Jamma connector
  • Buttons 4-6 on auxilary ‘kick’ connector
  • MVS remap – ‘Neo Geo layout’ on 6 button panels
  • Easy firmware update via micro-sd

*)  VGA connector chosen for convenience and availability of cables. The Jammafier does not touch the video signals generated by the Jamma PCB, and you will most likely need an additional device to modify the video signals for use with a modern monitor. Processed video/sync only available on revision 2.0 and newer.


Short version: I shall not be held responsible for destroying your PCB’s or if your house catches fire – check that your game and cabinet power supply is working correctly.  Your cabinet power supply is capable of delivering enough current to do serious damage to everything it powers.

Each time you use the Jammafier, you risk catastrophic failure of your cabinet, Jammafier or game.  You can substantially reduce this risk by:

  1. Assuring that every component is working correctly 
  2. Assuring that every component is connected correctly
  3. Obtain instructions on how each component is operating
  4. Never leave a powered system unattended

However, electronics sometimes fail to operate properly – even when properly assembled and operated – so you risk catastrophic failure or fire each time you use the Jammafier.

Last Updated on 2022-09-11 by admin