As mentioned previously, the NES controller is, at least from an electronics perspective, an extremely simple thing. It’s got one dirt-cheap chip, a parallel-in shift register, which receives cues from the system on two wires to send out its state over one. Even if there weren’t a currently-in-pieces NES controller on my workbench (there is), I would still have all the parts necessary to hack one up.
Well, almost. One exception.
The NES controller port is a delightfully obscure connector. It is in fact possible to get an NES plug or jack fairly easily, but at the very least this involves online ordering, where it’s possible to order such a connector, often without destroying anything, or locally tracking down a piece of equipment to cannibalize, such as a controller for the plug, a busted NES system or multitap for the jack , or, if you’re lucky, a controller extension cable with one of each.
It’s a good bit of trouble, and expensive compared to more generally available connectors. For example, a DE-9F connector for a from-scratch homebrew Sega Genesis controller will set you back only $2.19, and that’s if you source it from perennially-overpriced RadioShack. And you won’t have had to cut up any vintage equipment. Even if you do go the hack-and-slash route, you’ve got a lot more selection: DE-9 was ubiquitous through most of the ’90s in the form of PC serial ports (DE-9M) and anything that plugged into a serial port (DE-9F), such as a serial mouse, and there was at least one serial port on the typical desktop for a long time after USB had stolen its fire
For the application in question, I decided on another interesting possibility: Network cable. Because Ethernet over CAT-5/CAT-5e/CAT-6 has been popular for a good while now, its 8P8C connector is in plentiful supply from anyplace that sells computer accessories, and these are currently far easier to find than places that sell electronic components!
These cables have 8 conductors in 4 twisted pairs. This twistedness is meaningful at the high data rates of networking, but at the data rate in question, as long as the cable is reasonably short, it’s basically just eight wires in a bundle.
The cables themselves very often come pre-terminated with 8P8C plugs. While these have a somewhat fragile release tab, it works well enough, and the connector or the entire cable can be replaced easily (and generally cheaply). The corresponding jacks are a good deal more rugged, so they’re usually found on the equipment rather than the cable.
As for the jacks, it’s not impossible to find a nice insulation-displacement inline jack, depending on where you look. Additionally, to accommodate contractors building a structure with wired networking, building supply places like Lowe’s may have some options (look for the wiring section). If all else fails, it’s likely that you’ll be able to find a coupler in some of the same places that sell cables. One way to use a coupler as a jack would be to install a short piece of cut cable in the application circuit, in which case the still-terminated plug end serves as the connector; then use the coupler to make the plug effectively a jack. If you’re feeling bolder, some (perhaps most) couplers are actually implemented with wires on the inside. If the coupler is taken apart carefully, it might be possible to turn it into two jacks. And, of course, for the patient, PCB-mount jacks can be had for less than half a dollar Scavenging from used PCs or network hardware isn’t out of the question, either.
In terms of the NES controller, here’s how I would, and might, do it: I’d slash a controller extension cable fairly close to the plug end, leaving a short plug cable and a long jack cable. I’d reterminate the plug cable with an 8P8C jack. Optionally, I’d also re-cut the jack cable to be as short as the plug cable, and reterminate it with a jack as well.
And what has this gotten us?
- It’s a modular extension cord system for the NES. Attach the two adapters we just made to either end of any reasonably short network cable, and it’s suddenly an extension cable! (Okay, so we had an extension cable to start with, but now the length is adjustable by substituting longer or shorter patch cables.)
- It’s a means for developing swappable from-scratch NES controllers without destroying history. A simple or temporary project could use a single-ended cable soldered directly into the controller; a more finished product would use a board-mounted jack.
- Connectivity problems caused by a bad cable are easier to confirm.
So, even if this idea isn’t of the greatest utility, it’s an interesting thought.
-  Google “NES replacement controller port”. ↩
-  Harvesting from an original console or accessories is considered a huge faux pas by collectors and the nostalgic in general. ↩
-  If you happen to be near a Fry’s, you’ll pay less than a dollar, and they’re also very cheap from the major online electronics retailers. ↩
-  The serial port isn’t going anywhere for a long while, either, because RS-232 is still a very common interface in industrial control applications. ↩
-  also erroneously known as RJ45 ↩
-  Twisted pairs facilitate differential signaling, which allows low-noise/high-speed data transfer even with unshielded cable ↩
-  on the order of 1kbps ↩
-  I haven’t tried this, so no guarantees. ↩
-  And cheaper still if you get CAT3 jacks instead of CAT5 or higher, because in this application it shouldn’t matter. ↩
-  The extension cords aren’t usually counted as irreplaceable, and new ones are actually still being made. ↩
-  It’s possible that this is only of interest if you’re the type that builds and prototypes new controllers frequently. ↩