NES APU in Matlab

Discuss emulation of the Nintendo Entertainment System and Famicom.

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kyguy37536
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Re: NES APU in Matlab

Post by kyguy37536 »

Would it be at all possible to get some tracks before they've been mixed together? If not then a couple of random tracks would work.
kyguy37536
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Re: NES APU in Matlab

Post by kyguy37536 »

Actually, if they could all be tracks from super mario bros for consistency that would work. Thanks is advance. I'm looking to see if I can also implement the mixer as part of the project.
Rahsennor
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Re: NES APU in Matlab

Post by Rahsennor »

Four more tracks, in 7z format because zip broke the attatchment size limit.
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kyguy37536
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Re: NES APU in Matlab

Post by kyguy37536 »

Does the way you sample the output let you just take the pulse, triangle and noise channels separately before they've passed through the DACs?
Rahsennor
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Re: NES APU in Matlab

Post by Rahsennor »

kyguy37536 wrote:Does the way you sample the output let you just take the pulse, triangle and noise channels separately before they've passed through the DACs?
Not without significant modifications.
kyguy37536
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Re: NES APU in Matlab

Post by kyguy37536 »

Okay no problem. Thanks for all the help/data. Are there are any ideas off the top of your head that would maybe allow me to improve on the way that the NES processed the audio so I can go a little more in depth on the project?
Rahsennor
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Re: NES APU in Matlab

Post by Rahsennor »

kyguy37536 wrote:Okay no problem. Thanks for all the help/data. Are there are any ideas off the top of your head that would maybe allow me to improve on the way that the NES processed the audio so I can go a little more in depth on the project?
My goal as an emulator author is accuracy, so I honestly have no idea.
kyguy37536
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Re: NES APU in Matlab

Post by kyguy37536 »

Do you have the samples of the songs after the filters have been applied?
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Dwedit
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Re: NES APU in Matlab

Post by Dwedit »

NES generates those pretty square waves and triangle waves and stuff at sampling rates in the MHz, then everything after that is analog. No more emulation at that point, just simulating the effects of the circuits. Heck, you'd probably need an oscilloscope to see how close the NES's generated waves are to their ideal forms before any other analog stuff happens.
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FrankenGraphics
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Re: NES APU in Matlab

Post by FrankenGraphics »

The triangle is certainly going to look a lot less than ideal :lol:

Speaking of which, does anybody know the +/- voltage of the channels before and after mixing? Would be good to know when adding in ext. audio from a cart.
Rahsennor
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Re: NES APU in Matlab

Post by Rahsennor »

kyguy37536 wrote:Do you have the samples of the songs after the filters have been applied?
No, and I couldn't post them anyway, because it destroys the compression ratio. And my filters aren't hardware-accurate to begin with.
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