Old PC Games and GOG.com DOSBox; SOUND EMULATION

mrprmiller

Edit history:

mrprmiller: 2015-03-07 06:54:38 am

mrprmiller: 2015-03-07 06:54:21 am

mrprmiller: 2015-03-06 11:14:06 pm

mrprmiller: 2015-03-06 11:13:42 pm

mrprmiller: 2015-03-06 11:13:18 pm

mrprmiller: 2015-03-06 11:12:40 pm

mrprmiller: 2015-03-06 11:12:25 pm

2015-03-06 11:06:17 pm

Everyday is puppies and sunshine...

There's some notable old Sierra (and other) games that run amazing sound on the Roland MT-32 hardware, and Soundblaster just doesn't do the job once you've heard the Roland tracks. This Roland stuff is old equipment. It is possible to actually emulate the Roland on the official DOSBox releases, but it requires some extra settings outside of the official set up.

So here's the fun technical question: Emulators might be frowned on, but would it be acceptable to emulate SOUND drivers in runs, even if it is not part of an official (i.e., GOG) release?

Thread title:

BadJim

2015-03-21 03:55:14 pm

I'd say yes.

The rules:

"Software Modification: Removing or altering any part of a game is forbidden. Examples include software mods, the crooked cartridge trick, or disk streaming. Editing config files and console commands for PC games beyond the scope of the ingame settings are only allowed for purely cosmetic changes that grant no gameplay advantages."

There are two parts to this. Firstly, you'll be installing a MIDI driver. AFAIK, there are no real rules on which drivers you use as long as they don't enable you to cheat, such as OpenGL hacks that let you see through walls. They are not part of the package that comes with the game.

Secondly, you might be editing the config file so DOSBox uses your MT-32 driver. As quoted above, the rules allow you to edit config files for purely cosmetic purposes.

The issues with emulation in general are that most emulators do not perfectly emulate hardware, possibly affecting game mechanics. You don't want someone to skip half the game on an emulation with a trick that doesn't work on legit hardware. Emulating a MIDI device is different. It's just an implementation detail. Unlike an MP3 file which precisely defines the music, MIDI files just specify the notes and which instruments play them, so the emulation doesn't have to be perfectly accurate. As long as the right notes are played and resemble the right instruments, it will be working to spec.

I'd say yes.

The rules:

"Software Modification: Removing or altering any part of a game is forbidden. Examples include software mods, the crooked cartridge trick, or disk streaming. Editing config files and console commands for PC games beyond the scope of the ingame settings are only allowed for purely cosmetic changes that grant no gameplay advantages."

There are two parts to this. Firstly, you'll be installing a MIDI driver. AFAIK, there are no real rules on which drivers you use as long as they don't enable you to cheat, such as OpenGL hacks that let you see through walls. They are not part of the package that comes with the game.

Secondly, you might be editing the config file so DOSBox uses your MT-32 driver. As quoted above, the rules allow you to edit config files for purely cosmetic purposes.

The issues with emulation in general are that most emulators do not perfectly emulate hardware, possibly affecting game mechanics. You don't want someone to skip half the game on an emulation with a trick that doesn't work on legit hardware. Emulating a MIDI device is different. It's just an implementation detail. Unlike an MP3 file which precisely defines the music, MIDI files just specify the notes and which instruments play them, so the emulation doesn't have to be perfectly accurate. As long as the right notes are played and resemble the right instruments, it will be working to spec.

BadJim

Edit history:

BadJim: 2015-03-22 11:42:52 am

2015-03-22 11:15:15 am

Also, it seems that the Roland Corporation failed to copyright the two ROM files that are required for MT-32 emulation, which means they are public domain and it is not piracy to download and use them.

http://en.wikipedia.org/wiki/Roland_MT-32#Emulation
http://www.vogons.org/viewtopic.php?t=1979

Crow!

Edit history:

Crow!: 2015-03-24 12:41:02 am

2015-03-24 12:35:47 am

What's that gemma?

DosBox already is a slave to whatever MIDI driver your computer is using; there is no reason not to use the Roland emulator as your MIDI device.

However, using the game's install program to tell it that you actually have a Roland and not just some generic MIDI device is another matter. Sierra games usually store only the highest quality graphics, sound, and music formats and downscale to the hardware actually used on the fly. This means that there is extra lag when playing the game using a more typical setup (such as the GOG release's setup) compared to using the full features of a Roland emulator.

To see this most clearly, set DosBox to a lower cycles setting and try playing in 16 colors. This "easier" video format cripples the game compared to 256 colors.

BadJim

Edit history:

BadJim: 2015-03-24 11:26:40 am

2015-03-24 11:12:33 am

Quote from Crow!:

Sierra games usually store only the highest quality graphics, sound, and music formats and downscale to the hardware actually used on the fly.

For graphics, maybe. But MIDI is different. MIDI files are like sheet music, they specify notes, timing, which instruments to use, but they contain no information about the actual sounds. Games with MIDI music would send this information to the sound card and the sound card would figure out how to play the music. The Adlib/Soundblaster cards that most people had used would sound bad, while the expensive Roland MT-32s that were intended for studio use would sound great. But in both cases they would be using the same data, with no downscaling for cheaper cards.

I always thought it was rather silly because the Amiga sounded far better than PCs with Adlib/Soundblaster cards, even though Soundblaster cards (but not Adlib) were capable of the sample based music that made the Amiga sound so great. The music files were bigger of course, but not huge.

Also, 16 colour modes are more complicated than 256 colour modes due to the addressing scheme. Changing a single pixel in 256 colour mode means changing one byte. Changing a single pixel in 16 colour mode means changing a single bit in each of four bitmaps. Simply putting an image on the screen can be done twice as fast because there is half as much data, but other operations can get more complicated and it can actually take longer to do stuff in 16 colour mode.

[quote="Crow!"] Sierra games usually store only the highest quality graphics, sound, and music formats and downscale to the hardware actually used on the fly.[/quote]

For graphics, maybe. But MIDI is different. MIDI files are like sheet music, they specify notes, timing, which instruments to use, but they contain no information about the actual sounds. Games with MIDI music would send this information to the sound card and the sound card would figure out how to play the music. The Adlib/Soundblaster cards that most people had used would sound bad, while the expensive Roland MT-32s that were intended for studio use would sound great. But in both cases they would be using the same data, with no downscaling for cheaper cards.

I always thought it was rather silly because the Amiga sounded far better than PCs with Adlib/Soundblaster cards, even though Soundblaster cards (but not Adlib) were capable of the sample based music that made the Amiga sound so great. The music files were bigger of course, but not huge.

Also, 16 colour modes are more complicated than 256 colour modes due to the addressing scheme. Changing a single pixel in 256 colour mode means changing one byte. Changing a single pixel in 16 colour mode means changing a single bit in each of four bitmaps. Simply putting an image on the screen can be done twice as fast because there is half as much data, but other operations can get more complicated and it can actually take longer to do stuff in 16 colour mode.

Crow!

2015-03-26 07:10:40 pm

What's that gemma?

The Roland MT-32 has more functionality than basic MIDI, and the Sierra games did make use of those special functions if you informed the game that the Roland was available. When the Roland is not available (or if the game is told that the Roland is just some basic MIDI device), the game has to go through and strip away all the Roland-specific commands each time it loads a music track.

mrprmiller

2015-03-26 09:43:41 pm

Everyday is puppies and sunshine...

So if I'm understanding you right then, Crow!, the game would technically run faster (even though it is probably unnoticeable) because if it thinks a Roland is there it does not have to strip away the Roland-specific commands, correct?

Crow!

2015-03-26 11:32:22 pm

What's that gemma?

It will run faster if you run install.exe and inform it that there is a Roland - regardless of whether there actually IS one.

If you leave the installation settings unchanged, but use the Roland emulator as Windows's default MIDI device, then the game will run at the same speed, but will not make full use of the Roland's capabilities.

mrprmiller

2015-03-27 06:10:14 am

Everyday is puppies and sunshine...

Gotcha. Thanks for the info.