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PostPosted: 2014-03-19, 1:24:16 
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Hi all,
I came across this discussion (http://www.sega-16.com/forum/showthread ... st-results) and was wondering if YM3438 was an improved version of YM2612, would it be possible to play VGMs that were using YM2612 originally with YM3438? There were discrete and integrated versions of YM3438 though I'm not too sure whether the sounds produce between the two are distinguishable.

Thanks in advance,
VGMfreak


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PostPosted: 2014-03-19, 19:19:03 

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Last I checked, the VGM format does not distinguish btwn YM2612 and YM3438. Unkess ValleyBell made a change I'm not aware of, MAME and MESS VGM mods should also log YM3438 as YM2612.


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PostPosted: 2014-03-19, 23:53:15 

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MAME/MESS treats the YM3438 as a YM2612 internally, because there is barely any difference between them. They have the exactly same register set and behave in the same way.
The only differences that Wikipedia lists are related to the audio output itself.

(The only thing that's different between the YM2612 and YM3438 in MAME is the name. Everything else uses the code for the YM2612.)


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PostPosted: 2014-03-20, 3:00:28 
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Hi neologix, ValleyBell,
Thanks for replying. I know that the DAC was the only major component that was improved on the YM3438, I thought that MAME/MESS would have this difference between the ICs. I'm assuming that MAME/MESS emulates the YM2612's DAC for both ICs right?

Off topic - I tried ripping a gsf from a GBA rom using rom2gsf, when this gsf file was played in Winamp using the Highly Advanced plugin, it sounds like the corresponding game was being emulated without user input, there are random sound effects during playback of the music, presumably a demo mode, most sounds/music are coming from PCM_A channel and there's no further muting that could be done. How could I remove the sound effects so it just plays the music? Thanks.

VGMfreak


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PostPosted: 2014-04-02, 5:16:47 
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Perhaps I'm understanding things wrong, but from what little I can comprehend of the details of the YM2612 versus the YM3438 (and related FC1004), it seems that the differences between the chips could only be heard through use of actual hardware, and that any attempt to make a distinction between them in software emulation would simply be an implementation of deficiencies there is no point in emulating in the first place?

Or in other words, in order to emulate the theoretical superiority of the YM3438, you would have to introduce artificial problems with the emulation of the YM2612?



Off-topic: You'd probably be better off asking about GSF issues (and other things unrelated to the VGM format) at hcs64.com, or possibly somewhere like GBATemp (if someone has any other suggestions, that would be great). It would help to know what game you're working with, though.


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PostPosted: 2014-04-02, 19:58:32 
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http://www.ylw.mmtr.or.jp/~hosino/ma-ne ... ym2612.htm
http://www.ylw.mmtr.or.jp/~hosino/ma-ne ... ym3438.htm

メガドライブやFM-TOWNSで使われている2612とほぼ同等のもののようです。
It(YM3438) is almost the same as the YM2612 that Megadrive and FM-TOWNS used.


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PostPosted: 2014-04-03, 1:48:40 
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Well, I understand that you can't make 8-bit audio sound better, but the ladder effect was absent in the YM3438 which was caused by bit-depth truncation in the original YM2612, so I thought maybe their emulated counterparts would have these characteristics.


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PostPosted: 2014-04-03, 8:38:19 

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The YM2612 in all emulators whose source I checked outputs unfiltered 14-bit data (per channel).
For MAME and Gens (and VGMPlay) I know there is no additional filtering. Kega Fusion for example allows you to turn a "filter" on.


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PostPosted: 2014-04-06, 13:35:07 
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Thanks guys for clarifying, interesting to note Kega Fusion's filter, I thought it made the sound a bit muffled so I left it off...


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