These are the required components:


"Power Player III"/"Mega Joy III" 'nintendo on a chip' game controller.Search on google for a seller, sometimes they're available in malls. Completely pirate, but so much fun! Should run $25 with shipping.


"Hip Gear Screen Pad" or "Intec Screen Pad", these have been recently discontined but are still available at ToysRUs and similar places  for about $25-$40.

Now-adays I'd actually suggest going with one of the NTSC displays we have in the Adafruit shop as they have a true LED backlight which is thinner and uses a LOT less power


PacTec HP-4AA enclosure, which happens to fit everything just about perfectly. Available in ivory or black, sold by Mouser as well. $6


Original NES controller. Available just about everywhere for like, $5 or less. Or look through your stuff. You probably have one in that cardboard box.


  • Soldering iron. Nothin' fancy. Also, solder, solder sucker, heatshrink, wire, etc.
  • Hot glue gun & sticks
  • Superglue
  • Drill press/drill/dremel...something to cut the ABS plastic case.

Step by step

These instructions are a little rag-tag...there might be minor steps that are missing or incomplete descriptions. Hopefully they are still useful to someone.

Check out the case, put in the metal bits for the batteries.
Disassemble the 'HIP Screen Pad,' take out the screen (unplug the connector) and verify that it fits right above the battery compartment. The screw holes should line up. You might have to notch the pcb a little to let the HV (white & pink) wires around.
Disassemble the Megajoy.

Desolder the Famicom connector. Also desolder the ribbon cable. In order, the pinout of the bottom cable is (left to right as shown):

  1. Controller #2 something
  2. Controller #1 clock
  3. +5V to controllers
  4. C#1 data
  5. Controllers #1&2 latch
  6. Controller #2 something
  7. Controller #2 something
  8. Reset (pull low to reset)
  9. Ground
  10. Audio out
  11. Video out
  12. +5V in for nintendo
Connect the MegaJoy to the LCD. The LCD connect wiring is (according to my notes):
  1. N/C
  2. Adjust ground (grey)
  3. common with 2 (grey)
  4. common with 2 (grey)
  5. N/C
  6. N/C
  7. Brightness adjust (blue)
  8. Contrast adjust (yellow)
  9. Color adjust (white)
  10. Adjust power +5V (purple)
  11. Composite video in (yellow)
  12. Video ground (brown)
  13. N/C
  14. Power ground (black)
  15. Power (red)

(if there's a grey ribbon cable, see this diagram, courtesy of bquach)

For now, don't disconnect the adjusts (#1-10). Connect power ground to video ground to the megajoy ground. Connect lcd power to megajoy power and provide 6V (4xAA). Solder video in to the video out pin.

I also connected the original NES pad as shown. Note that there are a few ground pins on the famicom connector so you can use them as ground solderpoints.

The megajoy got taped to the case behind the screen. Turn it on. Should work :)

Note heatshrink on wires extended from the LCD.

I made a small version of the LCD adjust board but if I recall correctly, you just cut it off completely and the screen defaults to a nice setting.

(In case you want to make your own adjust board: Contrast is purple->2k->10K pot -> 2K -> grey. Brightness is purple -> 2K -> 10K pot -> grey. Color is purple -> 5.1K -> 10K pot -> 1K -> grey. A diagram is available courtesy of bquach. Mine looks like this. )

Cut up the nintendo controller for the valuable buttons, elastomers and pads. Scratch off some of the overlay so that you can solder to it.
Arrange the buttons as desired.
Cut out the holes for the controller.
Cut out the hole for the LCD (drill and then file? Whatever works for you).

(Not shown: Take the original controller for the megajoy and solder the pads from the NES controller to the epoxy'd chip in the middle. My notes claim that the pinout for the chip is as follows: (clockwise from 1 o'clock: select, start, B, turbo, A, ground, +6V (triangular trace), white/clock, yellow/data, orange/latch, left, up, gnd, right, down. I'd double check this visually, as I might have a mistake about the directional buttons. Basically a button press should short that signal line to ground.

Use superglue to tack the elastomers in the right spot. Put the buttons on top, hot glue the shards, place the case top and kinda push around the buttons until they are in the right place. Wait for the hot glue to dry.

Almost done! Make sure that all the power wires (LCD power, Megajoy power, controller power) all connect to the positive battery terminal. All grounds should eventually connect to the negative battery terminal.
Add batteries. If you feel like it, add a power switch of some sort (disconnects the batteries from the circuitry).
Now would be a bad time to drop one of the buttons under the table. (Found it eventually)

Extra stuff

I eventually added a headphone jack. You can use the audio amp chip in the megajoy and some sort of volume knob...

This guide was first published on Apr 12, 2013. It was last updated on Apr 12, 2013.

This page (Make) was last updated on Apr 10, 2013.

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