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DIY Vectrex Light Phaser

Instructions for making your own Sega Light Phaser to Vectrex Lightgun adapter. I’ll be making some of these available with the first lightgun compatible cartridge I produce. Stay tuned for more info 😉


Parts needed :

1 x Genesis/Atari cable (with all pins connected)

1x DB9 plug

1x DB9 hood

Tools Used :

Soldering iron

Hot Glue gun



The first job is to test continuity on the pins on the joystick connector with a multimeter to identify which coloured wires to use.

Vectrex Controller Pinout
Sega Light Phaser Pinout
Pin Mapping

SMS Pin 7 (Light sensor) to Vectrex Pin 4 (Button 4)
SMS Pin 6 (Trigger) to Vectrex Pin 3 (Button 3)
SMS Pin 5 (+5v) to Vectrex Pin 7 (+5v)
SMS Pin 8 (GND) to Vectrex Pin 8 (GND)

On the cable I used the wires are as follows :

Yellow : Light Sensor

Orange/Peach : Trigger

Grey : +5v

Black : GND

Next we isolate these wires and strip them for soldering to the plug.


On the plug, we solder to pins 5,6,7 and 8 using the pin mapping listed above.


Once soldering is complete, you should attach the DB9 hood and test the lightgun is working on the Vectrex. You may need to cut away part of the plastic connector with a craft knife to allow the connector to properly insert into the Vectrex. If you are unsure how to cut it, refer to the standard Vectrex connector shape.


If it is not working as expected, check pin-mapping and continuity with a multimeter and correct any mistakes made.

If working successfully with Vectrex, remove the top of the DB9 hood, add hot glue to hold the connections and attach the hood again.


Leave the glue to solidify for a few hours and then enjoy your new lightgun adapter!



Some of the forthcoming lightgun (and lightpen) compatible games are previewed in VectrexRoli’s video below :


9 thoughts on “DIY Vectrex Light Phaser

  1. Wow, that is cool!! Nice alternative to a lightpen (if you don’t own one but a Sega Light Phaser), fits perfectly to Whack-a-mole! 🙂

  2. Thanks for this guide !

  3. I can’t wait to try this out, I even have an SMS light gun. I knew it’d come in handy one day…

  4. This is absolutely incredible because now you can also play homebrew light gun games on it, and you can also use it with light pen games.
    But how about to also make a vectrex to SMS port adaptor to use the vectrex light pen on the master system, not only for light gun game but also for in the near furture homebrewed light pen games? Would be very awesome.
    In fact i really wish such adaptor for the nes along with homebrew games for it and i wish that color dinosour will be patched to support the light pen.
    I will definitaly buy one if.
    Let the wirld know.

  5. Will you make some driver sourcecode available for this as well?

    1. Yeah, I’ll make an example project once I release the games and adapter.

  6. Love the ingenuity!

    I wouldn’t just cut the unused wires down on the cable, a strand of wire could touch another wire. They are still connected to -5V, X, Y, buttons 1 and 2 . I would cut these at different lengths and maybe put a single piece of shrink tubing over to prevent this potential risk.

    An Amiga-gun should work as well, as you can use an adapter to use a SEGA-gun on an Amiga.

  7. I built the adapter and tested it with Whack-A-Mole and this is nuts! Can’t wait for your lightgun games compilation, sign me up for one 🙂 (Well, I’ll sign up for the newsletter for now, jaja).

    Keep it up and cheers!

  8. Dear Chris

    I am a huge light gun fan. Could you please consider remind me on this lovely project as soon as you release it, so I can buy one? That would be lovely =)

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