Nintendo NES Overclocking Guide

Deven "Epicenter" Gallo writes "I've perfected a process by which to overclock the Nintendo Entertainment System (NES) to run games smoother without slowdown. The NES CPU normally runs at 1.79 MHz, I've reached a stable maximum of 4.2 MHz, about a 230% overclock. The games do not run faster than they should, the CPU never overheats, and most games are perfect up to 3.3 MHz!" Here's the guide on how to perform the modification, along with photos and demonstration videos

Comments

Why?

[Anonymous Coward]

Many of you are probably asking, why in the world would you do that? Here:

What does this accomplish?
It's very common for games to push the consoles they are designed for to their limits, or beyond them. When this happens, the game slows down while it tries to execute all the instructions being thrown at it. Overclocking can greatly alleviate, or completely remove, this lag and make the games smoother and more fluid.

Re:Jumpy games?

[metricmusic]

I remember getting Megaman for a christmas present many years ago and it had slowdown at some points when there were alot of enemies on screen. Here aa review on the game that mentions the slowdown in it: http://www.nesplayer.com/reviews/mm2r.htm

A nice concept, but...

[Quietust]

...there would be some very significant side effects to such modifications:
1. NES audio is generated within the 'RP2A03G' (CPU) chip and is based on clock cycles, so doubling the CPU clock will cause the audio to go up an octave (assuming it even runs). The site mentioned in the article actually pointed this out, so it looks like it's legitimate.
2. Games which use cycle-timed code will no longer work properly - Battletoads is the first that comes to mind.
3. Some NES cartridges only used 250ns PRG ROM chips, which is only good up to 2MHz; go any higher and the game may not run at all.

Re:A nice concept, but...

[Epicenter713]

I tested about 10 games out (some of which I listed info about on the site). I don't have any that refuse to run-- every one handles at least 3.0 MHz. The pitch increase isn't as bad as theory would suggest it should be. In fact, it seems to kind of improve the tone of audio in some games, and a lot of the time, 'out of key' audio is put back IN key (most notably Metroid). That's my 2 cents. Sticklers for 100% perfect original audio won't be thrilled I'm sure. But I'm damn finicky and it still doesn't bug me.

Re:What else can I overclock?

[Gordonjcp]

Yes. There used to be PC clones that had a "turbo" switch on - that changed the CPU clock from whatever they were normally clocked at to 4.77MHz so that software that required precise timing loops would work correctly (step forward Sopwith...) on newer machines.

If you find that your CPU doesn't work at above 6MHz, try swapping it for an NEC V20 or V30 (can't remember offhand which) - this was faster even for a given clock speed, went to around 10MHz, and 8086 compatible into the bargain.

I used to have (probably still do somewhere) a Compaq 286 with a 6MHz 287 fitted instead of the 8MHz part. Worked just fine.

Re:Warning!

[a8o]

Actually, Nintendo used to offer a lifetime warrenty. You could get them to fix your NES if it overheated on its own, for example, due faulty workmanship. I read it the other day in the booklet I got with my SNES. Since the Gamecube and discs read by lasers, however, they've limited this lifetime warrenty to a year.

Re:Blowing is a waste of energy

[ProppaT]

Actually, you're completely off on this one. It has nothing to do with "moving corrosion"...it has everything to do with moisture.

The reason that blowing the carts worked (and still does for the most part) is that you're applying moisture to corroded terminals. Moisture = connectivity. That's why after you blow in a cart and put it in your system, sometimes it works for 5 minutes and then the game starts blinking. The moisture has evaporated from the terminals.

Bad thing about blowing in the carts (there had to be a bad thing) is the fact that, by applying more moisture to the cart, you expedite the corrosion. It works better now, but down the line it becomes even harder to get them to work.

You can scrub away all you like on most carts and even buy a new pin connector, but your games are gonna all run like crap. It's not the system, it's the carts.

Now if you REALLY want to try your best to get your carts to work, the real way of refurbing them is to get a nintendo bit for your screwdriver, take off the cover, and scrub (and scrub, and scrub) at the connectors with a white eraser. It's the only thing I've found that will do the trick. Also, if you really want to use a cleaner, an anomia based cleaner (like Windex) does a much better job than rubbing alcohol.

Not necessarily a *good* thing...

[Xoo]

Forgive me for linking to the file directly, but here's a direct link to a demonstration video showing the overclocking differences in Super Mario Bros. 3.

Instead of observing the obvious improvements in fluid animation (and gameplay), listen to the audio differences in both before and after overclocking. The original is exactly how I remember SMB3 to sound, while the overclocked version sounds kind of whacked.

To me, the audio from these classic games is JUST AS important as the video, so I won't be overclocking until a better method is found that won't screw up audio.... but I'd imagine the bulk of people who still have *working* NES units, wouldn't want to mess around with their precious vintage systems anyways ;-)