It is currently Mon Aug 19, 2019 3:17 am

All times are UTC - 7 hours





Post new topic Reply to topic  [ 9 posts ] 
Author Message
PostPosted: Wed Jul 24, 2019 5:38 pm 
Offline

Joined: Wed Mar 23, 2016 12:27 pm
Posts: 20
or can it only be extracted as both squares? the same could be asked about pin 2. would it be possible to extract all 3 channels individually?


Top
 Profile  
 
PostPosted: Wed Jul 24, 2019 6:07 pm 
Offline

Joined: Sun Mar 19, 2006 9:44 pm
Posts: 1001
Location: Japan
Not possible, without actually hacking the game ROM.

_________________
http://www.chrismcovell.com


Top
 Profile  
 
PostPosted: Wed Jul 24, 2019 6:24 pm 
Offline
User avatar

Joined: Sun Sep 19, 2004 9:28 pm
Posts: 4208
Location: A world gone mad
If you're trying to make a stereo mod: don't. None of the music was composed/mixed with such in mind. Mono -- deal with it.

NSF players (on Windows, etc.) are a different matter. You can certainly extract individual channels there, if you wish to do so. But this is obviously not using the NES CPU/hardware.


Top
 Profile  
 
PostPosted: Wed Jul 24, 2019 6:46 pm 
Offline

Joined: Wed Mar 23, 2016 12:27 pm
Posts: 20
ccovell wrote:
Not possible, without actually hacking the game ROM.

I see. thank you for letting me know.

koitsu wrote:
If you're trying to make a stereo mod: don't. None of the music was composed/mixed with such in mind. Mono -- deal with it.

NSF players (on Windows, etc.) are a different matter. You can certainly extract individual channels there, if you wish to do so. But this is obviously not using the NES CPU/hardware.


lol i never said that I was going to do a stereo mod.


Top
 Profile  
 
PostPosted: Wed Jul 24, 2019 6:56 pm 
Offline
User avatar

Joined: Sun Sep 19, 2004 9:28 pm
Posts: 4208
Location: A world gone mad
Pretty sure I started my line with the word if... :-)

But you're effectively wanting the same thing as what stereo modders always seem to want but can't get: to isolate all 5 channels for use in one way or another: viewtopic.php?p=241137#p241137

So with the NES itself, no, can't be done. But if you're wanting NES music split up on a per-channel basis, an NSF of the game(s) you like + an NSF player can do that. A Rasberry Pi with some added circuitry (since it only has digital output via GPIO pins, and you probably want analog?) + slightly modified NSF player code (to send each channel's data to a separate pin) should work. I mention this because your other thread already is discussing use of hardware (re: pots, which are just variable resistors).


Top
 Profile  
 
PostPosted: Wed Jul 24, 2019 8:28 pm 
Offline

Joined: Sun Apr 13, 2008 11:12 am
Posts: 8532
Location: Seattle
The math to identify exactly two pulse waves, out of a very limited set of volumes, duty cycle, and pitch, is actually really straightforward.

But it's also completely ridiculous. It would be computationally cheaper to emulate the NES than to do this math.


Top
 Profile  
 
PostPosted: Thu Jul 25, 2019 10:55 am 
Offline
User avatar

Joined: Sat Jul 04, 2015 9:58 am
Posts: 957
Location: -29.794229 -55.795374
I remember to have seem sometime ago a video of a guy that claimed to have done just that.
Unfortunately the video was removed, maybe it was fake?

I think the Retrousb AVS can do that, but it seems to be a NES on a FPGA.
Maybe if someone implements a full NES CPU on FPGA each channel can have it's own output pin, but it doesn't seems much practical nor straight forward.

Edit: Just in case someone is interested in the thread I posted the (now broken) link: https://forums.nesdev.com/viewtopic.php?f=6&t=16477


Top
 Profile  
 
PostPosted: Fri Jul 26, 2019 12:45 pm 
Offline
User avatar

Joined: Tue Mar 22, 2016 8:27 pm
Posts: 339
Location: Minnesota, USA
koitsu wrote:
If you're trying to make a stereo mod: don't. None of the music was composed/mixed with such in mind.

Wholeheartedly agree with this statement. It is one of those things that seems like a cool idea but it just doesn't work. The last version of RockNES by Richard Bannister on the Mac forced stereo, it wasn't even an option to go back to mono, and it really, really sucked.


Top
 Profile  
 
PostPosted: Sat Jul 27, 2019 12:27 am 
Offline
Site Admin
User avatar

Joined: Mon Sep 20, 2004 6:04 am
Posts: 3701
Location: Indianapolis
ReverendSA wrote:
ccovell wrote:
Not possible, without actually hacking the game ROM.

I see. thank you for letting me know.


It depends on the game, but I think in a lot of cases the hack might be fairly easy. I think many (most?) games only write to $4015 (channel enable) in a couple places. Games using DPCM might be different case though. But they'll write zero to it at reset, then $0F when enabling the audio. You could then make a Game Genie code to change that $0F, and enable/disable whichever channels you want. If you want to do it with an original cart.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 9 posts ] 

All times are UTC - 7 hours


Who is online

Users browsing this forum: Google [Bot] and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group