Megadrive soundtracks that explicitly use the ability to tune each operator independently

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lidnariq
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Megadrive soundtracks that explicitly use the ability to tune each operator independently

Post by lidnariq » Tue May 04, 2021 4:58 pm

I know this is the wrong forum, but sega-16 doesn't seem to have much in the way of either technical or musical focus, so ...

The YM2612 supports the ability to change one channel (or maybe two) so that it uses 4 independent frequencies (block+fnum) instead of ones that are related as simple integer ratios. VGMplay's source calls this "slot3 mode".

Are there any examples beyond simple proofs-of-concept of music written to make use of this feature?

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Re: Megadrive soundtracks that explicitly use the ability to tune each operator independently

Post by tepples » Tue May 04, 2021 8:22 pm

A user of Plutiedev mentioned Xenogears Xenosaga Xenoblade Xeno Crisis.

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Gilbert
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Re: Megadrive soundtracks that explicitly use the ability to tune each operator independently

Post by Gilbert » Tue May 04, 2021 10:29 pm

Just googled Xeno Crisis...

This is a fairly new game though.
I'm just curious. Are there any games released while the console was still current in its generation (even if it's near the end, like after the 32X and Saturn were out) that use such feature?
I wonder how many features/tricks that were never touched upon during the lifetimes of consoles, at least those that were not really hard to pull off at that time.
(By difficult to pull off ones, apart from undocumented quirks that were discovered recently and crazy codes used in homebrew demos, I meant examples like those that are only feasible nowadays because of technical/financial reasons, like requiring large amount of storage, etc.)

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Nikku4211
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Re: Megadrive soundtracks that explicitly use the ability to tune each operator independently

Post by Nikku4211 » Tue May 04, 2021 10:59 pm

Gilbert wrote:
Tue May 04, 2021 10:29 pm
Just googled Xeno Crisis...

This is a fairly new game though.
I'm just curious. Are there any games released while the console was still current in its generation (even if it's near the end, like after the 32X and Saturn were out) that use such feature?
I wonder how many features/tricks that were never touched upon during the lifetimes of consoles, at least those that were not really hard to pull off at that time.
(By difficult to pull off ones, apart from undocumented quirks that were discovered recently and crazy codes used in homebrew demos, I meant examples like those that are only feasible nowadays because of technical/financial reasons, like requiring large amount of storage, etc.)
I've heard that this unused song from Mega Turrican uses it, but I've never bothered to check.

I also could cite PC-88/-98 games that use the OPN and OPNA, which are in the same exact line of sound chips as the Mega Drive's OPN2 and have the same FM3Ext feature, most of which are generally produced in the same era, but they're technically not Mega Drive games so whatever.
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Re: Megadrive soundtracks that explicitly use the ability to tune each operator independently

Post by lidnariq » Tue May 04, 2021 11:22 pm

Nikku4211 wrote:
Tue May 04, 2021 10:59 pm
I also could cite PC-88/-98 games that use the OPN and OPNA, which are in the same exact line of sound chips as the Mega Drive's OPN2 and have the same FM3Ext feature, most of which are generally produced in the same era, but they're technically not Mega Drive games so whatever.
No, I'm just looking for the 4-independent-operators function being used musically. Don't care which specific Yamaha FM synth did it.

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Re: Megadrive soundtracks that explicitly use the ability to tune each operator independently

Post by tepples » Wed May 05, 2021 5:28 am

Sik says devs in Japan called ch3 free frequency mode "sound effect mode", which is why Streets of Rage uses channel 3 for all its sound effects. Flygon mentioned parts of Devilish for Genesis as well as the town theme in Champions of Krynn for PC-9801 (oscilloscope video) and parts of Grounseed for PC-9801 (oscilloscope video).

EDIT:
Mel. mentions WIZ N LIZ and maybe MR. NUTZ
JC dogen mentions gauntlet 4, demolition man, and apparently mega turrican

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Re: Megadrive soundtracks that explicitly use the ability to tune each operator independently

Post by lidnariq » Wed May 05, 2021 4:26 pm

I've now written tools to look for the specific event in a VGM log that writes to the OPN/A/2 to configure this mode...

WIZ N LIZ and MR. NUTZ
No, unfortunately.

Gauntlet 4
Yes, specifically the tracks "Sortie" and "Retribution", where it's used for 2 channels of 2op FM (the horns)

Demolition Man
Every track, almost exclusively for percussion (bass drum, toms) and sound effects (heartbeat, helicopter)

Mega Turrican
Only in "Stage 1 (Secret Area)", where it's used for 4-note chords.

Devilish
Only in "Stage 3 - Waterfalls", where it's used for 2 channels of 2op FM (two voices of the 3-voice melody in the chimes)

Champions of Krynn
9 out of 14 tracks.

Grounseed (OPN version)
21 out of 42 tracks - often two 2op harmonic parts

Grounseed (OPNA version)
Every track - often 2op percussion combined with 2op harmonic part
tepples wrote:
Wed May 05, 2021 5:28 am
Sik says devs in Japan called ch3 free frequency mode "sound effect mode", which is why Streets of Rage uses channel 3 for all its sound effects.
It does seem like it would be very easy to use it to make all sorts of weird avant-garde sounds.

Thank you very much to everyone for pointing me at these!

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