In most games, DPCM channel is used only a part of the time :
For example, in Fire Emblem, only a quarter of songs uses this channel. In Earthbound (that looks like have the same sound programm), DPCM channel is there when you're walking, but it's silenced if you open the menu (that's really crasy).
In other taclical games, like Famicom Wars and Just Breed, only 25% of songs uses this channel. In FW, it's usually not used during the war, but it's there only for intro, etc... In JB, it's usually unused in villages and it's used only in the battles (out of villages), exept at the begining.
For a last example, Final Fantasy3j uses just $4011 to do ticks impulsions to simulate kick drum (or something like this). This is used only for battles, and the noise channel is also used only in battles (exept sound effects).

That's strange, isn't it ?

Bregalad, Ent from the woods of Fangorn

"DPCM" can't be used in Mother when the menu is open, otherwise the mid-scanline CHR bankswitching timing would be (uncorrectably, probably) off.

You can convert a WAV music entirely to be playable in the NES hardware, making the DPCM channel busy all the time. I only saw TMNT demo by Xodnizel though, playing the cartoon theme music :)

"You can convert a WAV music entirely to be playable in the NES hardware"

You mean like this?

http://pinocchio.jk0.org/max-300.zip

____________________
My English is better than your Geberquen.

You can convert a wav to nes only via $4011, not via $4010/12/13 to have a good sample frequencey (otherwise all treble sounds will be cutted).
All theese games (exept FF3j) uses only $4010/12/13, not $4011, so I can't see why just some write to theese registers can break an IRQ.
And FF3j uses this only in battles, and IRQ triggering is also used only in battle ($4011 is set only in the NMI code, I think).

Bregalad, Ent from the woods of Fangorn

The DPCM frequency isn't a problem (it's highest rate is pretty good), but yeah the delta modulation smoothes out all sharp edges. It'd be a good idea to run a low-pass filter on a sample before converting to delta format.

Using DPCM steals CPU cycles, so that's why it's usually not used in cases where CPU timing is really tight. That, and I'd imagine back then not very many people had the equipment to make samples. I'd almost think that's the case for SNES even, it seems like many games all use the same samples.

Rad Racer 2 also does the $4011 drum popping sound (definitely only one or 2 writes per frame, because that game is very timing-dependant).

Ok, so I understand now why it's unused in Fire Emblem's battles, and in the war's screen in Famicom Wars. (and why it's not used at all everywhere in Double Dragon)
But games like CV3 uses DPCM everywhere, and Chr Bankswitching is switched via an IRQ, and it doesn't bug...
For Just Breed, there isn't any IRQs or CPU software waits, so I can't understand why this channel is somestimes avoided (or maybe the composeer doesn't like drums at all).
For Mother, there isn't any mid-frame Chr-Bankswitching while the menu is open, so this is not the actual problem.

Note : Somes trades like Bandai and Capcom looks to prefer don't use DPCM at all, maybe beacause this channel is in a software point too different from other, or maybe beacause they haven't any samples.

Bregalad, Ent from the woods of Fangorn

> For Mother, there isn't any mid-frame Chr-Bankswitching while the menu is open, so this is not the actual problem.

Oh yes there is. It's switching CHR banks twice every SCANLINE at each location that contains English text (since it doesn't have enough room to display both A-Z *and* kana at the same time).

--
Quietust
P.S. If you don't get this note, let me know and I'll write you another.

Huh ? I can't see anything like that. As I see, Name Tables contains only "standard" data (no characters are unvisibles beacause of Chr-Rom or anything like that.
But I did check only the English version, I'll do this for the japaneese one to understand it.
Note that one of the 3 battle's music uses DPCM, so it can't be used in (some) battles.

->Rad Racer 2 also does the $4011 drum popping sound (definitely only one or 2 writes per frame, because that game is very timing-dependant).
Yeah, it does, and SD Gundam 3&4 does both, too.
Is it possible to have a same effect with the MMC5's $5011 easyly ?

Bregalad, Ent from the woods of Fangorn

> But I did check only the English version, I'll do this for the japaneese one to understand it.

Umm, "Mother" is not English. "Earthbound" is English. "Mother" is Japanese. This is why I referred to ASCII vs kana.

"Earthbound" does not use mid-scanline CHR switching in the menus, because it did not need to.
"Mother" most definitely DOES use mid-scanline CHR switching, because it needed to.

--
Quietust
P.S. If you don't get this note, let me know and I'll write you another.

"Earthbound" is a Super NES game, based on "Mother 2". There is no NES game based on "Mother" unless you count what has been called "Earthbound Proto" or "Earthbound Zero".

If you suspect a code difference between a North American NES version of a game and a Japanese Famicom version, try clarifying it by using a (U) or (J) after the title.

____________________
My English is better than your Geberquen.

Yeah, I saw all this.
DPCM *must* be cutted only in the japaneese version of Mother, but english one also cuts it, uselessly.
This just can't explain to me why CV3'irq works fine with DPCM channel on.

Bregalad, Ent from the woods of Fangorn

> There is no NES game based on "Mother" unless you count what has been called "Earthbound Proto" or "Earthbound Zero".

Perhaps you should do a bit of reading... (http://www.lostlevels.org/200407/200407-earthbound.shtml)

Short answer: The 'Earthbound' NES prototype ROM is real. It is also far more than a simple translation, as it also changes numerous gameplay aspects. 'Earthbound Zero' is a hack (of said prototype) by Neo Demiforce that allowed the the game to be playable in Nesticle. Today's emulators can play the original dump without any problems.

Recap: The 'Earthbound' NES proto does not use mid-scanline CHR switching. The game 'Mother' does use mid-scanline CHR switching while the menus are open (in order to display ASCII text and hiragana/katakana at the same time), as seen below:



--
Quietust
P.S. If you don't get this note, let me know and I'll write you another.

Hmm. Seems this board has problems with images. Let's try this again...



--
Quietust
P.S. If you don't get this note, let me know and I'll write you another.

...and apparently, this board is incapable of having more than ONE image in a single post.

http://http:http://qmt.ath.cx/~quietust/images/mother.php

--
Quietust
P.S. If you don't get this note, let me know and I'll write you another.

...and apparently, this board is incapable of having more than ONE image in a single post.

http://qmt.ath.cx/~quietust/images/mother.php

P.S. Memblers, please delete my other 'broken' posts.

--
Quietust
P.S. If you don't get this note, let me know and I'll write you another.

Neat page, Quietust. I tried switching back and forth between 1 and 2 real fast - it almost felt like the real thing! :)
Btw, don't you love the way posts can't be edited on this board? Memblers, why don't you switch to phpbb? It's free and open-source. :)

I second the motion to switch to phpBB. It makes long threads SO much easier to deal with (since you don't have to hunt for the actual reply - it just appears at the end of the topic).

--
Quietust
P.S. If you don't get this note, let me know and I'll write you another.

J's probably just lazy. ;D

I could probably migrate things to phpbb for him sometime this weekend -- I did it for the Joy Electric folks, and I could probably do it again. Migrating posts and settings from an older version "looks" to be easy on the outside, but gets hairy if it doesn't work as expected.

Maybe a "test" board just to see how the migration goes and what people think, which could be switched over to the default board later?

-- jdc

Just my opinion: set up a new board and lock this one, meaning... don't transfer these "old" posts.

I would love to see a Wiki for NES info, a really simple one like http://tavi.sourceforge.net/WikkiTikkiTavi. I think it would be good as a way of giving an overview of NES development, and allow all the little bits of useful info that appear in threads over time to collect.

We should really make a new thread on this. :D

-- jdc

Just a few questions for tepples,
- Is the source code available for that Max 300 sound demo?
- Does the demo use raw playback or delta-modulation?


Abonetochew

http://pinocchio.jk0.org/ne3.zip

It uses DMC. I haven't compiled it in a long time because it's for x816, which doesn't like NT. I wrote it four years ago when LoopyNES Beta was the best emulator.

You have to change the "ROM size" field of neshead.bin to correspond to the size of the DMC data, which should be a power of 2 minutes 8 KBytes.

Want the original MP3? Go sign up at ddruk.com and download the DDR 6th Mix bumper pack.

____________________
My English is better than your Geberquen.