Belated Expansion

Today in Tedium: In case you were not aware of this previously, fandom always finds a way. Whether in the form of video game translation mods that emerged from the late ’90s emulation scene or the impressive work that has been done to bring PC gaming to Linux via Proton, there have always been attempts to stretch the accepted definition of what our game consoles allow us to do. Now, we have a new addition to add to that list: After 39 years, console modders have begun to develop ways to use the Nintendo Entertainment System’s infamous expansion slot, a key example of vestigial manufacturing. In honor of this amazing feat, which is being used to add Bluetooth and Famicom Disk System support to the console, I thought it might be good to take a look back at this fascinating wrinkle of history. Today’s Tedium ponders the legacy of the NES Expansion Port, and where it’s going next. — Ernie @ Tedium

Today’s GIF is from one of the earlier attempts to build an expansion port adapter, dating to at least 2012.

This hardware add-on is one of the most exciting things in retro at the moment. (via 8BitMods)

The hacks that are giving an old console yet another extra life

So anyway, let’s talk about this wild thing that has been getting attention in the Nintendo retro scene.

First announced in October, the NES Hub has gotten a bit of attention from the mainstream press for being one of the few commercial products that have leveraged the NES expansion port. It offers two key things for potential buyers: First, it adds wireless Bluetooth controller support to the console, and second, it leverages the expansion port to make available expanded sound, something previously possible only with the Famicom Disk System. Games actually built to take advantage of the extra channels will benefit most, but even those that don’t might have slightly punchier sound.

Tito Perez from the modding-focused YouTube channel Macho Nacho Productions did a full breakdown of the device, and it’s pretty cool. The developer of the board, Timo Röder of the boutique German electronics firm RetroTime essentially built the connector for the expansion port by himself, a lot of painstaking work that led to a unique product.

The product is currently on presale for $60, with orders expected to open up this month. And those who buy it will be able to further hack on the port through the addition of mini DisplayPort connectors that make the data lines avaliable to hackers. (Weird port choice, cool idea!)

But one has to wonder, now that they’ve built this thing, what the heck is possible with this expansion port? Could you create, for example, a Game Genie-like device that sits at the bottom of your console, kind of like an old Action Replay? Would it be possible to use a similar device to easily output video without needing to access the innards of the console?

It’s early days for this mod, which also makes it possible to access data lines that have never been made directly available to programmers before.

Already, people are taking steps to expand on some of the knowledge already built. This past week, Muramasa Entertainment shared video of a separate adapter for the expansion port that makes it possible to run the Famicom Disk System on a North American NES, something that was not easily possible until this mod was created. (Muramasa was also responsible for an earlier sound mod that used the expansion port.)

This was the video that made me want to write about this. Bluetooth is cool, but this is new territory. It’s also extremely niche, as highlighted by the fact that the mod is on presale for an eye-watering $250.00. (An $80 kit is also available if you feel like soldering.) If you buy it, you most certainly are a serious collector—a quick check of eBay suggests that buying a Famicom and a disk system together is cheaper than doing this. But the technical novelty is ultimately what makes this project special.

These two projects highlight perhaps how starved the retro community is for something new and interesting, given that, by definition, retro is old. Other attempts have been made in the past to mod the expansion port—notably, someone posted a tweet using a modded NES about a decade ago. But the fact that the curiosity around this port is leading to commercial products this far in suggests that there’s a certain pull to this mystery being solved.

The retro modding community has many success stories like this—from Game Boy screen mods to the entire concept of the MiSTer. But this one stands out to me because it adds a lot of functionality without requiring complex wiring and soldering to function. In other words, it’s approachable for end users, too. When that happens, it’s a breakthrough.

The Expansion Port Sound Module, one of the first attempts to expand the NES’ capabilities through its expansion port. The product was built as an open-source project, but Muramosa Entertainment was allowed to sell its own version. (Muramosa Entertainment)

Why did the NES expansion port only get used now?

As noted above, a not-so-hidden secret of the Nintendo strategy around its consoles is that, at least prior to the GameCube, they had a tendency to make big promises about additional hardware add-ons for the system … only to not ship them to the American market.

But the Nintendo Entertainment System was special in this regard. It was likely the first computing device that many people had in their homes, and that meant that people who spotted this expansion port were nonetheless curious as to why it was there. And given the fact that the gaming press wasn’t really poring over every detail like they do now, it wasn’t like people were looking for it. We didn’t immediately record teardowns of our hardware in 1988.

After all, it’s not like the Atari 2600 had an expansion port like this. Nor did most people’s VCRs. It was essentially a curiosity, a vestigial tail for an exotic new piece of hardware that would quickly take over the masses. Understandably, people were focused on the games.

Over the years, proposed use cases for the expansion port came and went. At one point, it was the key component of a modem planned by the Minnesota Lottery, but that never got beyond the test-market stage. (By contrast, the Famicom got an external disk drive, a BASIC-capable keyboard, and a karaoke microphone. It was also on the front of the console—serving double-duty as a port for third-party controllers that weren’t attached to the console—making it clear that Nintendo assumed its customers would use it this way.)

But if you were willing to use a tool to cut off the plastic permanently covering the expansion slot on later models, it would give you access to nearly every function natively supported by the NES, including a secondary way to access each of the controllers, direct CPU access, and lanes to access both the audio and the video elements of the console. If you are familiar with the concept of general-purpose input/output (GPIO) pins, as used on the Raspberry Pi and other single-board computers, the concept of the expansion port is similar. It’s a way to talk to the underlying components without actually using the ports.

In the past 40 years, there have been lots of attempts to expand the basic functionality of the NES, many of which have tended to favor the more visible ports—the Game Genie through the cartridge slots, accessories like the Power Pad through the controller ports. On top of this, the NES is one of the most heavily documented pieces of hardware around, thanks to its widespread use in emulation and the retro community.

Despite this, attempts to actually use the expansion slot for anything real were rare. I think a big reason for this is that you could access much of the console’s functionality through other means. If you wanted a wireless NES controller, for example, you could use the controller ports, which gave the device access to everything it needed. And the cartridge slot gave access to an additional 72 pins of data lines, including detailed access to the CPU and picture processing unit (PPU), though notably 10 of its pins were specifically dedicated to being used to communicate with the expansion slot, which no official games actually did. And the relatively large physical size of the cartridges compared to the physical circuit boards on which they connected meant that there was a significant amount of room to expand on the console’s hardware without ever touching the vestigial port—something that Nintendo itself took advantage of on games like Super Mario Bros. 3.

I think you could realistically point at the console’s design, specifically built for the living room, as one reason that it never got used. Another reason comes down to the relative weakness of its competition. Compare what Nintendo was doing with the NES to the TurboGrafx-16, for example. That was a console that got pretty significant redesigns during its lifespan, along with some fairly extreme variants. Likewise, the Sega Genesis tried to stand out with multiple design changes and system variants, offering at different stages both a backwards compatibility play through its Power Base Converter and an upgrade path with the 32X.

No, the Nintendo Knitting Machine, which itself never saw the light of day, did not use the expansion port. (Gamemaster Howard/Facebook)

With the NES, Nintendo was ahead most of this period. It did not need to do these things to stand out. The library was enough, and asking parents to take scissors or pliers to a covered expansion port was kind of a nonstarter in this light. It was already possible to “expand” the capabilities of the console through cartridges and controller peripherals, anyway. And let’s face it, nobody was trying to hook up the NES to HDMI back in 1987. Instead, comical gimmicks like the Nintendo Knitting Machine were on the table.

(I would argue that when Nintendo’s market position was shakier during the GameCube era. That’s when they started pulling out these expansions.)

So why are expansion port mods starting to emerge now? I think the easy answer to this is that it is relatively easy for enthusiasts to produce their own PCBs through a service like PCBWay, whereas it was basically inaccessible without startup capital previously. That means that if you want to develop an expansion board and commercialize it, the path to get there is easier than it has been in the past.

A mod like this is nothing new for the gaming community, but odds are that this one was more complicated because of the need to not only understand the system’s underlying technical mechanisms (which the community has long covered), but also how to build a physical adapter that works with a port that is used in exactly one extremely popular video game console. That’s a lot of combined expertise that needs to be mushed together, and it takes time.

But I also think there are likely technical reasons as well to start leveraging the port at the bottom. As these consoles age, it becomes more desirable to offer a mod-free way to add features like HDMI expansion, for example. The fewer moving parts used, the better. With that in mind, this mod is just one element that could keep these consoles alive for a few more years.

Of course, you likely have to be willing to permanently damage your console to get to the port, but you can always 3D-print a case if damaging a pristine part freaks you out.