VOGONS


First post, by sndwv

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Recently seeing how many different BIOS versions are supported by MUNT in ScummVM and DOSBox forks, I was wondering if there is any value in switching between them if all you are doing is game emulation.

My understanding was that just a CM-32 BIOS should be good for most uses (though very few games that also have digitized options actually use the extra sounds exclusively), and an 'old' MT-32 BIOS is good to keep for a subset of DOS games that exploit it specifically, but requires a delayed SYSEX workaround for some newer titles.

Is this indeed the way to go, or am I missing out somewhere?

Reply 1 of 6, by Spikey

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sndwv wrote on 2024-11-15, 10:30:

Recently seeing how many different BIOS versions are supported by MUNT in ScummVM and DOSBox forks, I was wondering if there is any value in switching between them if all you are doing is game emulation.

My understanding was that just a CM-32 BIOS should be good for most uses (though very few games that also have digitized options actually use the extra sounds exclusively), and an 'old' MT-32 BIOS is good to keep for a subset of DOS games that exploit it specifically, but requires a delayed SYSEX workaround for some newer titles.

Is this indeed the way to go, or am I missing out somewhere?

The CM-32L bios should be avoided when not needed, as it changes the panning to the incorrect panning used by that device (it is off slightly from "correct" panning that the MT-32 uses and therefore messes with the stereo image as intended, particularly with panned sound effects).

MT-32 old or new is recommended for normal use, old for strict compatibility, new for medium to high compatibility and slightly improved noise etc. Other non-hardware realistic hybrid options exist in MUNT, such as 32-but output with MT-32 old.

Reply 2 of 6, by sndwv

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Spikey wrote on 2024-11-20, 14:33:

The CM-32L bios should be avoided when not needed, as it changes the panning to the incorrect panning used by that device (it is off slightly from "correct" panning that the MT-32 uses and therefore messes with the stereo image as intended, particularly with panned sound effects).

MT-32 old or new is recommended for normal use, old for strict compatibility, new for medium to high compatibility and slightly improved noise etc. Other non-hardware realistic hybrid options exist in MUNT, such as 32-but output with MT-32 old.

Thanks for that, didn't know about the CM-32L panning issue. Do you know what's considered to be the 'best' new MT-32 BIOS name/version? I remember the newest 'Blue Ridge' BIOSes are not useful for emulation for instance.

Reply 4 of 6, by sndwv

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By the way, does MUNT emulate / replicate the MT-32 'old' buffer overflow behaviour, or is this an advantage it has over real hardware? Not sure if there would be any benefit to accurately replicating it, but perhaps it comes as a side effect of using the 1.0x BIOS.

If I would be keeping an MT-32 'new' BIOS, what would be the version to keep? Is 2.07 a good one?

Reply 5 of 6, by Spikey

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sndwv wrote on 2024-11-20, 15:22:
Spikey wrote on 2024-11-20, 14:33:

The CM-32L bios should be avoided when not needed, as it changes the panning to the incorrect panning used by that device (it is off slightly from "correct" panning that the MT-32 uses and therefore messes with the stereo image as intended, particularly with panned sound effects).

MT-32 old or new is recommended for normal use, old for strict compatibility, new for medium to high compatibility and slightly improved noise etc. Other non-hardware realistic hybrid options exist in MUNT, such as 32-but output with MT-32 old.

Thanks for that, didn't know about the CM-32L panning issue. Do you know what's considered to be the 'best' new MT-32 BIOS name/version? I remember the newest 'Blue Ridge' BIOSes are not useful for emulation for instance.

I don't really know the answer to this one. BlueRidge is part of a hardware mod, so the bios in isolation isn't useful, although it could be paired with a new bios potentially.. I'm not sure. Most likely it is not useful.

I would probably advise the newest bios and setting the MUNT for gen 1 appropriately. Although most games will be "better" (as composer intended) with original "rev 0/gen 1" settings. Really, it doesn't matter all that much in any case.

For the "best" output you could use the 32-bit float option which surpasses the OG hardware.

And yeah, the CM-32L thing I discovered last year.. It's quite wild! Neither the MT-32 or CM-32L panning works as it's supposed to, but the CM-32L one suffers from weird division math which compounds it and deviates it from the MT-32.. so it should definitely be avoided, except for CM-32L specific games.

Last edited by Spikey on 2024-11-29, 05:19. Edited 1 time in total.

Reply 6 of 6, by Spikey

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mannycalavera wrote on 2024-11-20, 15:32:

This page has a list of mt32 compatible games with the specific model recomended

https://www.vogonswiki.com/index.php/List_of_ … _computer_games

There's a lot of good information on here, looks like NRS edited it because not many would know this level of information. Although, every Sierra/Dynamix game has the tagline "Distorted/incorrect sounds on MT-32 'new'", which I'm not sure is actually correct. Certainly most Sierra games were composed with the original "rev 0/gen 1" MT-32, but that doesn't mean more than a handful of outlier instruments (and probably mostly sound effects) are affected in any sort of noticeable way.