~Hakurei Shrine~ > Tech Support
How do I make Anex86 emulate YM-2608 (OPNA) music + rhythms?
Momiji:
Not too sure why it's doing this, but I may have a theory based off something I read on a Sega Megadrive/Genesis emulation forum (the MD/Genesis uses a YM2612, a.k.a. OPN2, same family of FM synth chip).
The OPN chips are based on Yamaha's higher-end FM chips, but instead of a real accumulator-based mixer they time-divide the output of the channels (one slot every 24 clock cycles of the FM chip, apparently). So Anex86 may be implementing a time-division multiplexer (hardware-accurate emulation), while Hoot does actual mixing (high-quality sound).
You might be able to see this happening if you compare the waveforms from Anex86 and Hoot recordings.
From what I also read, 55khz is the proper sampling rate for the OPN-series chips.
By the way, the forum thread is here, very interesting reading if you like hardcore sound synthesis and electronics. Plus it's very relevant to the PC98 too, as both system's synth chips are related, and quite a bit of their material comes from the OPNA documentation.
Momiji:
Scratch that, I was wrong. Both the YM2203 (OPN) and YM2608 (OPNA) have internal accumulators. =[
So I really don't know why Anex86 and Hoot sound different. It could just be differences in the sound emulation cores.
unicode787plus:
I tried the T98-Next emulator, and it sounds quite a lot like the Anex86 except it adds rhythms and beats to the music (as if the music were native OPNA).
Also found a YouTube video of someone playing the original TH01 title theme as captured from T98-Next, and indeed it sounds VERY DIFFERENT from Hoot (but very similar to Anex86 except for the added Speakboard beats):
http://www.youtube.com/watch?v=i5QfOOtp31I&feature=PlayList&p=CD0FF1519A6E496A&index=0
I also played original TH02 & TH03 on T98-Next and they sound very OPNA-esque (while Hoot only emulates their original non-TH05-remix music as FM-26k without any rhythm at all).
Looks like I am losing faith on Hoot and trying to embrace T98-Next instead (although I should admit it doesn't run quite as smooth in my WinVista x64 machine as Anex86 does - music often stutters, speeds up, slows down, etc. even if I commit T98-Next to one single CPU core and give it 8 MB of running RAM).
::::EDIT::::
I found some way for Hoot to emulate original (non-TH05-remix) TH01-03 music as if it were using the Speak Board. I just had to edit the file doujin.XML by changing "opn" to "opna" on the <driver> tags and "pmd" to "pmdb2" on the <rom> tags. Attached is my modified doujin.XML with the original opn lines enclosed in <!-- -->. Now I love Hoot, after tricking it into using Speak Board. Now it sounds a lot like T98-Next.
But still, for gameplay purposes, I would stick to Anex86, it is more stable in my 64-bit computer... Even if I don't get Speakboard music.
hyperbolic colin:
--- Quote from: unicode787plus on July 03, 2009, 04:13:55 AM ---I found some way for Hoot to emulate original (non-TH05-remix) TH01-03 music as if it were using the Speak Board. I just had to edit the file doujin.XML by changing "opn" to "opna" on the <driver> tags and "pmd" to "pmdb2" on the <rom> tags. Attached is my modified doujin.XML with the original opn lines enclosed in <!-- -->. Now I love Hoot, after tricking it into using Speak Board. Now it sounds a lot like T98-Next.
--- End quote ---
I followed your suggestion and modified my Hoot's TH01 original music config in the same way, changing the driver type from "opn" to "opna" (no rom changes, since I was only modifying TH01), and the result sounds very similar to that YouTube video you mentioned. The tempo is still a bit slower; perhaps the version in the YouTube video is a bit too fast.
The TH01 Japanese documentation on the Touhou wiki makes it clear (once you find and translate the hardware requirements) that the sound was indeed designed for FM-86 ("Speak Board") OPNA hardware. Pity that all the TH01 replay videos on YouTube have been recorded with incomplete music support.
LHCling:
Ah, I thought something was wrong lacking with my BGM.
...cheers for chowell for giving me incentive to 1cc PC-98 Lunatics again.