While Not Quite Possibly the World's Smallest N64, This Crafty Console Mod Is Too Good to Pass Over!

The Nintendo N64 holds a special place in my heart.

It was my first — and if I'm honest, only — games console that I have ever owned. I played Perfect Dark until my thumbs hurt, memorized the maps of GoldenEye, and almost do most of the Mario Kart tracks from muscle memory.

So when Cameron Coward recently covered GmanModz's latest N64 handheld console mod, I was inspired to look deeper at how it was pulled off.

This miracle of miniaturization led me down a rabbit hole of investigation — looking at the techniques that go into such an accomplishment, and all I can say is after seeing the efforts put forward by fellow modder @NoahOfBitBuilt, I'm left with the impression that this scene is almost more of an artform than anything else!

We're going to take a look at some of the skilled work that goes into the process of cramming cleaved down circuit boards into functional handheld versions of the games consoles of yesteryear, by taking a look at this crafty console mod that we can see doing it's Donkey Kong thing in the image below.

While the 3D-printed enclosure suggests that this might be a fairly straightforward build, the lesson of judging things by appearances is bought to mind when we are presented with the glorious view of all of the hardware that has been hidden away inside...

Holy hardware hackery Batman!

Take a minute just to look at the entire system view as it is laid out before us. There's a lot of hardware going on inside this handheld!

At it's core, this is a "pure" mod, in that it, like GmanModz's handheld, also uses a rather aggressively trimmed down original N64 PCB. With varying levels of savagery, one can slim down on the stock circuitry, by slicing and dicing around the functional component blocks found on the original hardware.

I first saw this technique with some of the Nintendo Wii mods, and —although I was not aware you could do similar magic with a N64 — it makes sense, as the boards come from the same design teams and processes.

GmanModz appears to be the authority on this topic, with his "Advanced Trim" guide showing the step-by-step surgical operations that are required to condense down the original console.

The red perimeter on the image above indicates what is effectively the bare minimum circuit for the "trimmed" console, but we can see from the image below, detailing the rear half of the console, that Noah has taken things even further.

From the reorientated socket for the Expansion Pack, to the extra trimming of the GamePak header socket, there's a level of dedication that goes in hand with this approach — it's a lot of work vs a custom, aftermarket board!

For example, where as both of the consoles we're covering here could have opted for such aftermarket boards as the N64 3X3 (shown above) — a 3" square board, re-laid out, ready to accept donor chips that have been lifted from the larger stock motherboards, we have to really give credit where due with regard to the diligence shown in dicing up these boards.

It's not all hacksaw hacking though...

Beyond the trimmed N64 main board, we can see where the aftermarket hardware scene starts to show up — first up with some polished power management circuitry, designed with the power requirements of the N64 in mind.

Lower left of the previously covered image showing the rear of the handheld console, there's a custom power management module — the N64 PMS.

This is a PIC16F15324-driven module that manages a Texas Instruments BQ25895 combo single-cell Li-ion charger / DC/DC boost converter, providing a hefty 5V rail, and a secondary, switching 3.3V buck regulator output.

Proper PIF Placement

A secondary breakout board handles the transplantation of the "PIF" aka, Peripheral Interface — one of the critical components in the N64 component architecture, that is responsible for an impressive list of functions - ranging from PAL / NSTC video output, to interfacing with the controllers — it also contains the boot ROM for the console's 93.75 MHz VR4300 MIPS CPU, and is even responsible for coordinating with the CIC — part of the GamePaks security / anti-copy mechanisms.

It doesn't look much, but this SOIC-28 is critically important — so much so that there's another BoB from GmanModz that handles this heart transplant, ensuring that this system functions as intended, such that the console is blissfully unaware of the butchery it has been subjected to!

Helpfully, this one has sources available, with Gerber and KiCAD files linked here.

Poking and prodding the PIF...

While not used in these builds, researching the PIF functionality turned up this rather interesting project — the UltraPIF — a Lattice LCMXO2 / STM32 combo module that opens up some very interesting possibilities for poking and prodding around with the PIF functionality — and being an open project, this seems like something we should probably cover in it's own write-up soon enough!

Dishing out the details on the display

With the core of the console neatly coaxed into the rear of the handheld's case, we can take a look at the front face — which features nearly every circuit construction technique known — from flexible PCBs, to free-form, dead-bugged component work!

First and foremost, the most striking part to jump out of this juxtaposition of FPC connections and flying wire circuitry is the Altera Cyclone FPGA, sitting proudly on its prominent orange carrier board.

This module is the UltraVGA, a variant on the UltraHDMI upscaler / video converter from @Retroactive LLC — here, it is configured to interface to the 4.3" IPS LCD module used in this build.

This is one of the more impressive bits of wirework, with the normally FFC/FPC connection here formed of discrete point-to-point wiring. Hats off to Noah for this delicate work, it's very impressive — especially without the custom FPC cabling that would normally make the admittedly, still tricky job just a touch easier!

Controller inputs? Check!

Towards the bottom left of the layout, sits what is quite literally the core of the N64 controller, the main IC and it's MVP in regard to tracking, cleanly cleaved from a controller PCB.

While there again, custom aftermarket boards designed to simplify the use of these chips, there's obviously nothing wrong with reusing the stock hardware, with a bit of a trim, to break the board down to the bare minimum required for the controller to read in the various buttons and analog joystick inputs.

With point-to-point wiring winding its way to the custom button PCBs, and additionally to the joystick FPC breakout board, this could be considered as one of the simpler parts of this beautiful build!

And to top it off, the dead-bugged (what I'd bet is a) Microchip ATMEGA168, handling the joystick analog interface is simply a work of art to behold!

Aptly amplified audio

No console game would feel right without the glorious synthesized sounds that were originally scored for it.

So to ensure that the N64 has some way of singing out the soundtrack to your Super Smash Bros 64 Sesh, Noah has wired in what looks like slightly older version of the BitBuilt 64-AMP board, along with two small speakers for stereo sound!

This I2S interfaced audio amp board accepts the digital audio stream directly as it is generated by the N64 Reality Signal Processor (RSP), before converting it to analog and amplifying the signal in order to capably drive the speakers.

A work of wiring art

There's something to be said of the balance of literally having at a PCB with a hacksaw, to then almost surgically stich it in place with such skillful soldering. While nearly every single one of us would eventually likely say "sod this," and perhaps pull in one of the aftermarket boards — the props for using the original hardware surely makes the perseverance demonstrated here worth the effort.

Here's hoping we get a few more of these incredible console recreations to review in the near future!

If this has got your retro gaming interest piqued, keep up with these mad modders — Noah is on Twitter here (@NoahOfBitBuilt), or check out BitBuilt.net for Forums, guides and even a handy store for some of the parts mentioned in this article!