Amiga2JAMMA

This is a work in progress

Here you'll find instructions on how to make a JAMMA adapter for an Amiga computer to be able to connect it to an arcade cabinet. For this you'll need:

  • 1 x Amiga motherboard
  • 1 x power connector
  • 1 x video connector
  • 2 x joystick connectors
  • 2 x male RCA connectors
  • 1 x JAMMA fingerboard
  • 1 x sound amplifier
  • Wires, solder, soldering iron
The fingerboard connects to the power, video and joystick ports on the Amiga so these instructions should work for A500, A600 and A1200. It's possible to use an A2000, A3000, or A4000 motherboard as well, but the power connector is different.

Soldering the adapter is only half the job, you'll also need some way of storing, selecting, and starting games. Of course, you could just keep a stack of floppy games and swap as needed, but a hard disk and a menu program is a much more elegant solution. Some old games won't run off of anything but a floppy but you can find HD-installers for most games.

The joysticks and the three buttons will be connected to the Amigas joyports but the Start buttons should probably be mapped to something like Esc and Enter. P1B1 + Start 1 + Start 2 will issue a reset.


Amiga monitor
connector (DB23F).
JAMMA fingerboard.

Amiga A500/600/1200
power plug.

Amiga joystick
connector (DB9F).

Connectors used

Soldering Instructions

  1. Connect Signal GND, +5 V, and +12 V from the Amiga power plug to GND, +5 V, and +12 V on the JAMMA fingerboard. Leave -12 V disconnected -- I don't think it's needed and the computer appears to work just fine without it.

    Amiga power   JAMMA
    1. +5 V - 3. +5 V
    3. +12 V - 6. +12 V
    4. Signal GND - 1. GND

  2. Connect Analogue Red, Analogue Green, Analogue Blue, Composite Sync, and GND from the Amiga monitor connector to Red, Green, Blue, Sync, and Video GND on the JAMMA fingerboard.

    Amiga video   JAMMA
    3. Analogue Red - 12. Red
    4. Analogue Green - N. Green
    5. Analogue Blue - 13. Blue
    10. /CSYNC - P. Sync
    16. GND - 14. Video GND

  3. Connect Up, Down, Left, Right, B1, B2, B3, and GND from the Amiga port 2 joystick connector to the corresponding pins for Player 1 on the JAMMA fingerboard. Repeat for Player 2.

    Amiga joystick   JAMMA
    ?. ??? - ?. ???

  4. Keyboard connection is underway...

  5. For reset we need an active low signal. To minimize the chance of an accidental reset we'll require three of them to be pressed at the same time. A 4075 3-input OR gate is used like this: 
                       ___
    P1 B1    3 ----\  -.
                    |   \
    Start 1  4 -----|    )---- 6  /RESET
                    |   /
    Start 2  5 ----/__-'        .gif me!
    We probably need a cap and some pullup resistors for this to work.

Sound Amplifier

The Amiga's RCA sound output has to be amplified before you can connect it to your arcade speakers. If your cabinet only has mono sound you also have to mix the stereo signals to one. The quick and dirty way to do that is to connect them with three capacitors like this: 
    L in  ----o-||-o----.
                         >----o-||-o----  mono out
    R in  ----o-||-o----'
The caps should be something like 0.1 µF. Schematics for a simple mono amplifier can be found on the PC 2 JAMMA page.