Dirty NES Glitches

Existential Dread is part of the fun

The original model NES was/is notorious for its bizarre design choices. What started as an effort to differentiate itself from its predecessors became the bane of every child's existence. Nintendo didn’t want anyone to think that the NES was a video game console. Reasonable, considering what video game consoles were prior to the NES; I wouldn’t want to be involved with that crowd either. The redesigned console they came up with was more VCR like and had two major upgrades. With composite output and detachable controllers, the NES allowed the Famicom to become what could have been the best version of itself. Have you every used a Famicom? It's rough, to say the least.

Unfortunately, the redesign also introduced flaws so massive that they fundamentally change the experience. The Famicom, for all of it's problems, is an extremely reliable piece of hardware. The NES? Well, if the image above doesn't give you war flashbacks, you're either tremendously lucky or have never used the hardware.

The NES’ cartridge port was a severe bottleneck, and that led to all sorts of bizarre situations affecting these poor children who just wanted to play video games.

Because the NES utilized a ZIF connector, there was very little friction between itself and the cartridge inserted into it. Dust and other filth would naturally build up on the cartridge contacts. This is stuff that is imperceptible to people, but problematic when it comes to maintaining electrical signals. When kids put these dirty games into their Nintendo, that filth was then deposited into the machine. What makes this different from any other cartridge based system?

The ZIF connector in action

In attempting to be unique, the cartridge mechanism broke everything. Every other cartridge based console is self cleaning. You'd put a game in your Genesis, and the act of doing so, would cause the pins on the connector and the cartridge to scrap against one another. This alone was enough to keep both parties nice and clean. The NES, with it's "Zero Insertion Force" connector, leaves this part out, which caused nothing but problems in the long run. Any dirty game you put into your NES runs the risk of contaminating it.

I always suspected this to be the case, but I wasn’t certain until I read Console5’s Tech Wiki a few years ago. They stated the same as I’d suspected, and since they have the best NES repair manual on the entire internet, I’m gonna go ahead and assume they’re right. Though I will say, It’s not unlikely that two people can come to the same wrong conclusions using the exact same logic. People have really latched on to the idea that the pins aren’t making a connection due to lack of grip. In my experience, this isn’t true. In fact, those of you that are using after market pin connectors that supposedly "solve" this problem are making it worse. That's a write up for another day though.

As if a terrible cartridge port wasn't enough, Nintendo had the audacity to tack on an early form of DRM. The Famicom once again, had no such thing. Both the NES and the game had matching “lock" and “key” authenticator chips. The Lock was within the console, and would trip the reset line continuously unless it could detect a signal generated by the game cartridges key chip.

They called it the 10NES chip, and it’s responsible for everything wrong with your life when you were 6. These two chips must be in perfect sync in order for the game to boot. Since the cartridge port sucks so hard, you’ll often find yourself dealing with a game that works perfectly, but isn't being properly authenticated by the DRM. This'll manifest as the legendary blinking light. You'll see the games title screen, you'll hear it's music, but you can play. Generally, you could solve this problem by wiggling the cartridge a bit and powering the game on. This can easily devolve into a massive point of failure and lead people to think the console is dead. If you were playing one of the few games that had the ability to save, may God have mercy on you. The 10NES will not. The act of power cycling the console in order to solve this had the nasty side effect of wiping out save data.

the chip responsible for everything

Sometimes, the 10NES would fail mid game. What? You thought the lock only needed the key at boot? Nope. The lock and key must communicate continuously. Every single microsecond that your NES is powered on, those chips are talking. The slightest interruption, no matter how minor, will trigger it and kill your game. My grandmother once gently brushed against the wall near my NES and the vibration triggered the thing. It was relentless and quite frankly, excessive. Really though, this all comes back to the cartridge port. It's terrible, and I'm sure that had they used something traditional, there'd have been no issue here.

gives a whole new meaning to "crash"

You’d be playing Super Mario Bros 3, you’re up to the 6th world, you’ve never seen it, there’s ice everywhere, you’re stone cold focused. Suddenly, the screen goes black, and you see those familiar red curtain blinking in and out of existence. Your soul leaves your body some time between the first and 3rd cycle of this, never to return. What was worse is walking into the kitchen to get something and hearing this happen because your dog had the audacity to walk into the room. Any little vibration would trigger it: dogs, grandma, siblings, didn’t matter. Since it’s resetting in second long intervals, you’ll hear the first few notes of the game's theme repeat incessantly until you turn the machine off.

How NES Games store Graphics internally. Look familiar?

Unlike most video game consoles, the NES had a tendency to keep running despite severe graphical glitching. Traditionally, an NES cartridge consists of a PRG-ROM - which contains game code, and a CHR-ROM for graphics. These two chips communicate with the the CPU and the PPU respectively. The CPU is self explanatory. PPU is short for Picture Processing unit, and is more or less isolated.

The PPU has little interest in talking to the CPU. Allow me to explain as simply as I can: the PPU loads an abstract pattern table from the cartridge (see above). The CPU will give it instructions on how to arrange everything to make it look like something. It'll tell the PPU "Hey! Put Tile $A5 over here!" but it doesn't know or care what tile $A5 actually looks like. the PPU will simply reference whatever it sees and place it.

Now, Let's say the cartridge connector is making perfect contact with the CPU, but poor contact with the PPU. what'll happen?

this

You could boot up Duck Hunt, and end up with something that sounds and plays like Duck Hunt, but visually is a scrambled abomination. This was always a treat because it was infrequent. often the connection would be so tenuous that you could actively see it struggling. Lines would flicker back and forth, Mario’s face and legs would be swapped, The Duck Hunt Dog would have two faces – weird stuff.

My copy of Quattro Adventure was always dirty. I don’t think that I ever saw what Linus Spacehead was supposed to look like. His entire body would always be a garbled mess. We never played Quattro Adventure because it sucks, but If I wanted to see this in action, that’s where I knew I needed to go. Sometimes we actively wanted to see graphical glitches. We'd screw with the cart with varying results. Often we'd only get jail-bars. Occasionally we'd stumble upon something wild though.

I love it when NES games boot into the wrong thing. Imagine putting in Mega Man 5 and seeing a random glitched up stage instead of the title screen. This happened to me more than once, with multiple different games.

Dragon Warrior used to boot to something like this sometimes

My copy of Dragon Warrior was dirty, and would power on straight into the above animation. I was no older than 10 when I first saw this and I'm still fascinated by it. This is such a creepy and confusing thing to happen to a child. It made Dragon Warrior seem even more mysterious than it already was.

I can easily explain the other two problems, but I still don’t fully understand this one. In the case of Dragon Warrior, this happened the very first time I ever tried to play it. I wasn’t sure what was going on, and gave up on it for a time because that’s all I could get it to show. I know this sounds insane, but believe me, it was very real.

Sometimes, Tetris would boot and a glitched up rocket would take off. Super Mario Bros./ Duck Hunt was another weird one. Rather than boot into a random level, this one would occasionally just boot straight to Duck Hunt. When I was 4 or 5, I was deathly afraid of Duck Hunt because of its title music and the way the dog would pop up out of the grass. While I don’t remember when this happened the first time, I remember being afraid of it happening again. It wouldn’t be until I was in my mid 20’s messing around with an NES I’d just repaired that I’d see this happen again. I’m glad I saw it, cause it meant I wasn’t crazy.

what my child brain probably saw

I remember an instance where every single glitch scenario I’ve described occurred all at once. trying to play Mega Man 5, the graphics were corrupt, the lockout chip was blasting that reset circuit, and of course, it was booting into Gravity Man’s stage. Just a complete mess, all caused by that cartridge port being filthy, but the console being unwilling to crash outright. I have repaired tons of these consoles in my lifetime, and the problem is almost always that the pin connector is dirty. If you want to keep your NES in good shape, make sure you’re cleaning your games, make sure you’re NOT using a Game Genie, or better yet, just use an Everdrive and never remove it.

my favorite air fortress level

NES glitches like these haven’t happened to me in years because when I do play NES, I usually use an AVS or some kind of Famicom variant. I had to induce the examples used in this article, so forgive me for that. During the winter months of 2022, I played through all of Final Fantasy III on my newly repaired childhood NES. I used an Everdrive, and plugged multiple weeks of play into it. It’s completely unmodded, so the lockout chip could have started its shit but never did. Having a clean NES makes a world of difference. I don’t recall it crashing once, even after hours and hours of play.

Young people these days have no interest in the NES. They see it at best as a novelty and at worst as something completely unworthy of the time required to master. I’m not surprised, but it does sadden me until I remember I viewed Atari stuff in the same way growing up I never bothered attempting to emulate the 2600. I bought one and used the real hardware. Imagine if someone were to do what I did today with the NES. It’d put them off of it forever. That’s ignoring the fact that the television they’d be using would be fundamentally incompatible with the console.

What about controllers? There’s so many garbage bootleg controllers floating around, waiting in silence for a chance to ruin your life. The days of using NES hardware to play NES games are long over, and I’m fully aware of that. The barrier to entry for new users is way, way too high. Emulation is the way to go. Download the Switch App, or use some other method. Playing NES on an NES isn't worth it if you're not already involved with the hardware. You don't need me to tell you that. For me, part of what made the NES so memorable as a kid were these hardware induced glitches. In spite of how annoying they were, I’ll miss them, and I lament the fact that others will never experience them.