Sunday, May 8, 2011

The NES



Before we dive into the incredible sounds of the 2A03, I want to link to another example of FM synthesis:

http://www.youtube.com/watch?v=RKP_etVa_EU

The most obvious thing you may notice is that the quality of the sound is incredibly high compared to the more rudimentary stuff produced by the Mega Drive. As awesome as the YM2612 sounds, there really isn't much comparison. Sadly, however, I still have no idea what they produced that soundtrack's music on.

With that aside, let's dive into the glorious 8-bit sounds that we all know and love produced by the Nintendo Entertainment System!

Fortunately, the sound chip on the NES, the Ricoh 2A03, is quite a bit easier to understand than the Mega Drive's YM2612. It does not use FM synthesis, but instead four simple oscillators to create sound. But what is an oscillator? Well, I'm not going to get too far into the details, but it's basically a rudimentary waveform created by a repeating electronic signal. To visualize, let's look at a square wave:


As you can see, it actually does resemble a series of squares! Why over complicate things, right? Of course, now, you're probably wondering what a square wave actually sounds like. To put it into perspective, the two square wave channels are most commonly used for melodies and harmonies. They have a much greater presence than, say, the triangle wave, which we can see here:


The triangle wave, on the other hand, is used mainly for bass. It has a low, resonating tone, which makes it perfect for the job. But what about the white noise? Well, it's not as easy to visualize:


But that's because it's just a bunch of static. I'm sure you're familiar with white noise, the loud sound you hear when you tune in to an invalid channel on your television. But how could that possibly be of any application? By itself, it isn't, except for certain sound effects. But when you change the rate at which the volume fades out, you can create some very nice percussion!

So those are the four channels that create all of the sounds you heard in NES music. Pretty amazing, right? But I mentioned a sample channel earlier, too. That's the DPCM channel, or differential pulse code modulation. The name is only there to confuse you. It's just a sample channel. Ever wonder how they got the voices into Tecmo Bowl? Well, now you know! On that topic, I recommend checking out the music for the game Journey to Silius. The composer actually loaded bass samples into the DPCM channel instead of just using triangle waves. The result is one awesome soundtrack.

But not everyone was satisfied with only five channels. A few developers actually created their own sound chips to further enhance the audio capabilities of the NES, most notably Konami and their VRC6. The device, which was packaged in certain game cartridges, doubled the amount of channels available for use. Sadly, however, anyone outside of Japan was never able to experience this. The Japanese NES, the Famicom, was the only system that had support for the external sound chips. The localized NES did not. So certain games like Castlevania III didn't feature the audio that the composers intended. Compare the following two songs to hear the difference:

US/European Castlevania III
http://www.youtube.com/watch?v=GGq9VjJXVh8

Japanese Castlevania III
http://www.youtube.com/watch?v=vC4fYdrfS64

Well, hopefully now you're a bit more knowledgeable about the wonderful chip known as the 2A03! If you're really curious, you should check out the program Famitracker. It's a music making application that emulates the 2A03, allowing you to create NES music right at your computer! Here's a random video I pulled from YouTube that demonstrates this program:



Hope you enjoyed!

37 comments:

  1. Very informative and interesting post. I've always loved the old-school video game music.

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  2. very interesting! i want to have my amiga back :D

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  3. Wow you know so much about this stuff. Makes it more fun to read. Nice post.

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  4. Enjoyed big time, gotta love the old school music :D

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  5. Always fun to read posts made by people who knows their stuff! All respect to you, and ppl who has made them, it liiks pretty hard to get into.

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  6. Much interesting, I love the NES sounds, quite funny to see it broken down like this.

    +1 followed for more wisdom.

    Check out my blog aswell!

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  7. Its rare I learn something, new and interesting in the same day. Thanks.

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  8. This is awesome, you know a lot of this stuff.

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  9. You've done your research. Good stuff. It's always nice to find another audio guy.

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  10. You have impressed me... consider me impressed...

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  11. I learned some stuff on sound and frequencies in my physics class and I must admit you know your stuff really well :]

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  12. I would've enjoyed if I hadn't gotten so lost. I read the whole thing tho.

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  13. You really know your stuff... wow.

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  14. @Gaston Haha, don't feel too bad, I tried to make it as simple as I could, but oscillators and synths in general are pretty foreign to the majority of people. It's something that's easier to understand with hands-on experimentation. I might do a post on just oscillators sometime, maybe the history of synthesizers, too. Although, I already have in mind what I'm doing tomorrow.

    Glad you all enjoyed it!

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  15. Interesting stuff dude, sadly I'm too young to of ever owned a nes

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  16. Great article! Good youtube vid!

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  17. Nice man, really enjoyed that article

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  18. thank you for keeping me informed!

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  19. Wow this was intense. Thanks for simplifying it so I could understand haha

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  20. Love your blog style! keep up your excellent blogging!

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  21. Very informative article that is only better by the fact that it's the NES.

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  22. You should teach this stuff as a profession, I never understood all these waves and frequencies in school..

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  23. sweet :) the video reminds me of such good times! And thank you for this really informative artile.

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  24. This absolutly awesome, very interesting !

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  25. Awesome, I'll have to put this knowledge to good use.

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  26. Quite a difference in those two castlevania tracks. And interesting to know the white noise is whats was used for percussion.

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