Question about Monkey Island EGA + CMS music

[vanfanel]

Hello there,

The Creative Music System (CMS) audio is pretty much my favorite way to play Monkey Island (EGA) as I find it very fitting.

However, I have noticed multiple times that, after entering the bartender room on the Scumm bar, music on the Scumm bar never comes back.
The rest of the musics on the game seem to be normal, but the Scumm music never appears again!

Is this a bug, or is it how the CMS music is "scripted" into the EGA game?

[MusicallyInspired]

It doesn't happen that way in DOS so I'd say this is a bug.

[vanfanel]

It doesn't happen that way in DOS so I'd say this is a bug.

Seems I already reported this back in 2018

https://bugs.scummvm.org/ticket/10696

[Praetorian]

It doesn't happen that way in DOS so I'd say this is a bug.

Seems I already reported this back in 2018

https://bugs.scummvm.org/ticket/10696

Might worth confirming (on the bug ticket too) that the bug still exists recent developer builds (2.6.0git?) you've tested.

[MusicallyInspired]

Ah yeah my daily build is a little old. I tested it in "2.3.0pre (Oct 1 2021 13:19:16)" and it was broken there.

EDIT: Just tried latest daily build (2.6.0git2179-g25c63234e49) and it's still broken.

[Praetorian]

Ah yeah my daily build is a little old. I tested it in "2.3.0pre (Oct 1 2021 13:19:16)" and it was broken there.

EDIT: Just tried latest daily build (2.6.0git2179-g25c63234e49) and it's still broken.

I've issued a possible PR to address the issue:
https://github.com/scummvm/scummvm/pull/3638

[Praetorian]

Two additional issues that I've noticed:
1) Using CMS, when music is playing (eg. at the Scumm bar), any sound effects will not play (open/close door sound). In Adlib, music and sfx can play at the same time, so this is specific to CMS (could be happening to other sound modes, but I've only checked for CMS due to testing for the above bug fix). Can anyone who plays also with DosBox confirm whether CMS allows playing music and sfx together in the original, or this is some limitation of the CMS?
2) The music volume does not seem to be affected by the in-game ScummVM controls (I didn't test with the ones in the Edit Game launcher screen or Global Options launcher screen yet). This affects CMS emulation and Adlib emulation that I've tested. Probably is a more general issue, and ScummVM specific.

[AndywinXp]

2) The music volume does not seem to be affected by the in-game ScummVM controls (I didn't test with the ones in the Edit Game launcher screen or Global Options launcher screen yet). This affects CMS emulation and Adlib emulation that I've tested. Probably is a more general issue, and ScummVM specific.

This is something I always wanted to investigate (it also happens in MT32/Adlib mixed mode, and both audio sources - music and sfx - are mixed on the same channel). It won't be trivial, I can bet on that

[vanfanel]

1) Using CMS, when music is playing (eg. at the Scumm bar), any sound effects will not play (open/close door sound). In Adlib, music and sfx can play at the same time, so this is specific to CMS (could be happening to other sound modes, but I've only checked for CMS due to testing for the above bug fix). Can anyone who plays also with DosBox confirm whether CMS allows playing music and sfx together in the original, or this is some limitation of the CMS?

I can confirm that Monkey EGA on DosBOX does what you say: sound effects don't play while music is playing.
For example, door sound when closing/opening the door from inside the Scumm Bar, is not audible.
However, if you enter the kitchen on the Scumm Bar, where the boiling sound can be heard, kitchen door IS audible (from inside the kitchen, where NO music is playing!).

Monkey EGA works with CMS audio if you select the GameBlaster card, set it's address to 220, and run Monkey with "monkey G", in case someone wants to replicate my experiment.

[MusicallyInspired]

1) Using CMS, when music is playing (eg. at the Scumm bar), any sound effects will not play (open/close door sound). In Adlib, music and sfx can play at the same time, so this is specific to CMS (could be happening to other sound modes, but I've only checked for CMS due to testing for the above bug fix). Can anyone who plays also with DosBox confirm whether CMS allows playing music and sfx together in the original, or this is some limitation of the CMS?

Door sound effects do not play when the Scumm Bar music is playing in DOSBox. Seems to be a CMS limitation.
EDIT: Ninja'd. Also, yes you launch with "monkey g" but DOSBox must also have OPLMODE set to CMS in the dosbox.conf. (when in CMS mode Adlib will not work. It's one or the other)

Also, the CMS music in DOSBox seems to be pitched a whole step higher than ScummVM. But I've heard that Game Blasters/Creative Music System cards are based on CPU timing and could vary in pitch (and speed) from system to system depending on its cpu's clock speed so I'm going to call this a feature, not a bug.

[Praetorian]

Also, the CMS music in DOSBox seems to be pitched a whole step higher than ScummVM. But I've heard that Game Blasters/Creative Music System cards are based on CPU timing and could vary in pitch (and speed) from system to system depending on its cpu's clock speed so I'm going to call this a feature, not a bug.

This may be due to a specific fix for the cms emulation code in ScummVM. Here's the relevant PR, merged a while ago:
https://github.com/scummvm/scummvm/pull/825

The CMS emulation assumes the chips run at 8 MHz clock, but in PCs they run at 7.15909 MHz, so the emulated pitch is too high. Adjusting the requested sampling rate higher by matching amount the pitch is lowered down to normal.

[vanfanel]

Thanks to praetorian, this is fixed upstream now, and anybody can enjoy Monkey Island EGA + CMS music with no problems!

Great!!!

[MusicallyInspired]

Yey!

[JohnnyW]

Hmm. I'm having no sound effects at all in Monkey 1 EGA. Even outside the Scumm Bar or in the kitchen. I've tried Stable build Daily Build on MacOS x64.

MT-32 music is playing fine, though. Anyone got any ideas? Thanks!

[Praetorian]

Hmm. I'm having no sound effects at all in Monkey 1 EGA. Even outside the Scumm Bar or in the kitchen. I've tried Stable build Daily Build on MacOS x64.

MT-32 music is playing fine, though. Anyone got any ideas? Thanks!

This issue is not relevant to the topic of this thread.
I did mention it over on our Discord server here:
https://discord.com/channels/5812240605 ... 6974092351

I would suggest though that you open a ticket on our bug tracker so that we can log it, track discussions and progress on fixing it.