Gimmick! Repro Tutorial


Hey there!

This tutorial tells you how to make a (Mr.) Gimmick!-Repro for the Nintendo Famicom.

If you want to play it on a NES system please be aware you need to modify the NES and the 60/72-Pin-Adapter in order to hear the additional sound channels.

Gimmick! uses a special sound chip for it's awesome music. The chip is called "SUNSOFT 5B", or 5B for short. Gimmick! was officially the only game to use that chip.

Luckily though some other games used the chip (or similar chips) as well, so we can use them as a donor cartridge for this tutoral!

I'll use the japanese version of Gimmick (Gimmick! (Japan).nes, CRC:15F688B6), since I like it the most. Hacks of the game and the beta version should work with this tutorial as well.

MANY MANY THANKS to: the guys over at & xIceMan in particular! Without his help this tutorial wouldn't have been possible.

Special thanks to Commodore64 for spending love and kisses whenever I felt sad.

Suitable donor cartridges

Gremlins 2: Shinshu Tanjou


Barcode World

Dynamite Batman

Honoo no Toukyuuji: Dodge Danpei

Pyokotan no Dai Meiro

Prepare your EPROMs!

Have your romfile split by a tool like famirom.

You could do it with a hex editor by that's unnecessary difficult.

When you got your splitted rom burn the CHR and the PRG-parts to your EPROMs.

I recommend using EEPROMs since thay last quite long. UV-erasable EPROMs are fine too, but they won't last as long as EEPROMs.

If you can't do this step by yourself just contact me (, the guys over at or consider buying a preprogrammed (E)EPROM from a shop.

Consider buying two 27C020, they work fine and are probably cheaper to get then two different EEPROMs. Most seller offer special deals when you buy them in a lot.

Open the shell and identify the sound chip

If you wonder how to open Famicom cartridged just have a look at this video by arfink on youtube:

If you don't have a clamp at hand you might want to try the way harder way by poking screwdrivers into the shell. It'll most probably damage the shell though. Just have a look at google for this method (can't recommend it).

After you've managed to pop up the game search for the square ic and read the printing on it.

It's pure luck which sound IC you get. You get either a 5A, a 5B or a FME-7.


I found the sound ic, what now?

These games come either with a 5B (less modifications needed ) or an 5A / FME-7 (more modificatiosn needed). Just refer to the tutorial below, whenever you have to do modification depending on your sound ic it'll be highlighted!

Step 1: Desoldering (5A and FME-7, 5B)

In the first step you'll have to desolder and remove the original mask roms. Just flip the pcb over and desolder every leg of the mask roms.

A desoldering station comes in handy, but solder wick will do the job too. If you don't know how to desolder electronics, head over to youtube.

Have a look at some (partly) desoldered pcbs:


If you got a botched wire like on the 5B-board and the FME-7-board - just remove it.

Step 2: Free the sound pins (5A and FME-7, 5B)

Remove the coating of the trace between the 45th and 46th pin of the cartridge's pcb and cut it.

I used a fiber glass pen to scrape the coating away. Make sure not to cut the trace away completely since you have to solder wires to them.

The trace you need to cutCoating removed, note the shiny copper tracesCut tracesSolder wires to the exposed copper traces

When in doubt of a physically strong connection glue the wires to the pcb in addition to your solder job.

Step 3: Prepare your 5B (5B only!)

In this step you have to solder some wires to your 5B.

Lift these pins and solder wires to it: 2, 3, 27

Then solder a wire to pin 32, but don't lift it.

Have a look at this image for your reference:

Double check if the pins are disconnected from the pcb's footprint!

Step 4: Prepare your 5A / FME-7 (5A & FME-7 only!)

In this step you have to solder two wires to your 5A / FME-7.

Solder the wires to the 9th pin and the 32th pin of your sound IC. Don't lift them!

Have a look at this image for your reference:

Step 5: Solder down your CHR-EPROM (5A and FME-7, 5B)

Your desoldered CHR-MASKROM has either 28 or 32 pins. Just follow the next next table for rewiring instructions.

28 pins32 pins

Lift pins 1, 2, 24, 30, 31 and 32

⚫ Leave pin 1 unconnected

⚫ Connect pin 2 to hole 22 of the donor cartridge (A16)

⚫ Connect pin 24 to hole 14 (GND)

⚫ Connect pin 30 to 5B Pin 26 (see picture below!)

⚫ Connect pin 31 & 32 to hole 28 (VCC)

No modifications needed, your solder your EPROM down

Step 6: Solder down your PRG-EPROM (5A and FME-7, 5B)

You have to bend some pins on your PRG-EPROM do some rewiring. Lift pins 1, 2, 24, 30, 31 and 32.

⚫ Leave pin 1 unconnected

⚫ Connect pin 2 to hole 22 of the donor cartridge (A16)

⚫ Connect pin 24 to hole 14 (GND)

⚫ Connect pin 30 to 5B Pin 32 (you attached that wire in step 3 or 4)

⚫ Connect pin 31 & 32 to hole 28 (VCC)

See some examples:

Pin 31 & 32 joined together and soldered to hole 28

Pin 2 connected to hole 14

Pin 30 to 5B Pin 32

Pin 24 to hole 14, I soldered it to the via next to it

Step 7: Test it! (5A and FME-7, 5B)

The game should be working at this point. Go ahead and test it before starting the next steps.

Step 8: Reproduce the sound circuit (5A and FME-7)

We are going to create this circuit:

See those circled letters? Connect these together. If you have trouble locating some pins, have a look at the end of this step.

Shopping list:

⚫ 3x 1 kOhm, 0.25W metal film resistor

⚫ 2x 3 kOhm, 0.25W metal film resistor

⚫ 1x 1uF, ceramic capacitor

⚫ 1x 10uF, 50V electrolytic capacitor

⚫ 1x 1N4148 diode

⚫ 1x 74LS139, DIP16

⚫ 1x 74LS74 , DIP16

⚫ 1x AY-3-8912, DIP28

The AY-3-8912, fetch it at aliexpress

The 74LS139 and 74LS74, get it at your local electronics supplier.

Some random pics I took while putting the circuit together:

Thanks to xIceMan for noticing I got the capacitor soldered in the wrong way around !

Step 9: Reproduce the sound circuit (5B only!)

We are going to create this circuit:

Shopping list:

⚫ 1x 1 kOhm, 0.25W metal film resistor

⚫ 1x 10 kOhm, 0.25W metal film resistor

⚫ 1x 100kOhm, 0.25W metal film resistor

⚫ 2x 1uF, 50V electrolytic capacitor

Perfboard, at least 10 x 7 holes, 2.54mm

Either follow the schematic above (it fits nicely in that empty corner in the shell!) or follow this graphic to create the circuit:

Here are some pics of the finished board. Note that I used striped perf board!

Searching for the pins to solder the wires on? You prepared the 5B in Step 3:

In step 6 you prepared the cartridge connector:

Step 10: Create a label (optional)

Consider printing a label which clearly shows the game is a reproduction.

Just click the images below to download a high-res and correct size psd-file ready for printing.

The measurements of these graphics are 92.3mm x 43.5mm, exactly the same as a sunsoft-label.

made by punkpolitical

made by me


This concludes the tutorial. If the game won't work just drop me a mail or take your questions to a bigger audience at the forums of!

If it works - gratulations, have fun and play the game!