DOSBox Pure Core in Retroarch produces Roland MPU-401 error.

[SiriusVI87]

Hey everyone,

I was trying to Launch Alice's Adventures in Wonderland with DOSBox Pure in Retroarch. I am using the dosbox.conf file to launch the game via Launchbox. Everything seems to work fine, including the audio. However, I get this MPU-401 driver error in the beginning. If I just hit OK, I can hear the audio playing, so I don't know what this error means.

Can anyone tell me what I have to do to get rid of it? The error does not appear if I use the eXoWin3x version of the game, however, I'd like to use overlays, shaders and save states, that's why I want to use the DOSXBox Pure Retroarch Core.

[SiriusVI87]

This error does not appear if I use the regular DOSBox core in Retroarch. Does DosBox Pure have to be set up differently so the MPU Driver works correctly?

[schellingb]

You have to enable MIDI output in the Audio -> MIDI Output setting, otherwise the MPU401 device is disabled.

[SiriusVI87]

I have set Midi Output to "Roland SC-55". I have also tried various other settings, such as MT-32. But I still always get this error.

[SiriusVI87]

You have to enable MIDI output in the Audio -> MIDI Output setting, otherwise the MPU401 device is disabled.

By the way, this here is the .conf file I'm using to load the game in DOSBox Pure. It was taken from the eXoWin3x collection. Maybe there is something I need to change in the .conf file for it to work?

And just to be clear, the game does run with this .conf file in DosBox Pure, and there is even (some) audio when in game (though during the intro screen there is no audio when there should be). It's just that this error appears every time the gameis launched and there is some audio missing.

And again, this same .conf file works without the error when using the regular dosbox core in retroarch. Any idea what could be wrong here?

(Sorry, couldn't attatch the file, so here are its contents:)

[sdl]
fullscreen=false
fulldouble=false
fullresolution=0x0
windowresolution=640x480
output=openglnb
autolock=true
sensitivity=100
waitonerror=true
priority=higher,normal
mapperfile=mapper-0.74.map
usescancodes=true
[dosbox]
language=
machine=svga_s3
captures=capture
memsize=63
[render]
frameskip=0
aspect=true
scaler=normal2x
[cpu]
core=auto
cputype=auto
cycles=55000
cycleup=10
cycledown=20
[mixer]
nosound=false
rate=44100
blocksize=1024
prebuffer=20
[midi]
mpu401=intelligent
mididevice=default
midiconfig=
[sblaster]
sbtype=sb16
sbbase=220
irq=7
dma=1
hdma=5
sbmixer=true
oplmode=auto
oplemu=default
oplrate=44100
[gus]
gus=false
gusrate=44100
gusbase=240
gusirq=5
gusdma=3
ultradir=C:\ULTRASND
[speaker]
pcspeaker=true
pcrate=44100
tandy=auto
tandyrate=44100
disney=true
[joystick]
joysticktype=auto
timed=true
autofire=false
swap34=false
buttonwrap=false
[serial]
serial1=dummy
serial2=dummy
serial3=disabled
serial4=disabled
[dos]
xms=true
ems=true
umb=true
keyboardlayout=auto
[ipx]
ipx=false
[autoexec]
mount c .\eXoWin3x\AAiW
imgmount d ".\eXoWin3x\AAiW\cd\ALICE.cue" -t cdrom
d:
path=C:;z:;c:\windows\
@cls
@win runexit alice
exit

[schellingb]

Ah, you're using a .conf file. Notice how your .conf file sets the midiconfig option of the [midi] section to an empty value. The settings in the .conf file take precedence over the core options. You have to do one of these:

• Remove the line midiconfig= from the .conf file to use the core option
• Change it to something like midiconfig=X:\path\to\MySoundFont.sf2 to fix playback with a .SF2 SoundFont
• Change it to something like midiconfig=X:\path\to\SomeMT32_Control.rom to force using MT32 emulation with the given ROM

[SiriusVI87]

Ah, you're using a .conf file. Notice how your .conf file sets the midiconfig option of the [midi] section to an empty value. The settings in the .conf file take precedence over the core options. You have to do one of these:

• Remove the line midiconfig= from the .conf file to use the core option
• Change it to something like midiconfig=X:\path\to\MySoundFont.sf2 to fix playback with a .SF2 SoundFont
• Change it to something like midiconfig=X:\path\to\SomeMT32_Control.rom to force using MT32 emulation with the given ROM

Hey thx, I will try that for sure and report back.

I'm guessing that the reason why regular the dosbox core does not give this error is that it handles the empty value of the "midiconfig" differently? It probably reads an empty value the same ways as if the whole line "midiconfig" wasn't there, correct?

[schellingb]

I don't know how the other cores work... I assume they fully ignore the .conf setting of the [midi] section and only use the core option. If an empty midiconfig is somehow very common, we could add special handling to ignore such a line in the .conf file. But as of now it works like described above. Hopefully you get it working!

[SiriusVI87]

I don't know how the other cores work... I assume they fully ignore the .conf setting of the [midi] section and only use the core option. If an empty midiconfig is somehow very common, we could add special handling to ignore such a line in the .conf file. But as of now it works like described above. Hopefully you get it working!

I made a quick check of all the .conf files in the eXoWin3x collection. As far as I can tell, the "midiconfig" line is always empty. So your suggestion of having dosbox pure ignore this line if it is empty, could be a good idea.

For further information, I was able to distinguish three different types of .conf fies in eXo's collection that may be of interest to you.

1. case looks like my example above:

[midi]
mpu401=intelligent
mididevice=default
midiconfig=

2. case has some lines added, but the midiconfig line is still empty:

[midi]
mpu401 = intelligent
mididevice = fluidsynth
midiconfig =
fluid.driver = default
fluid.soundfont = .\mt32\SoundCanvas.sf2
fluid.samplerate = 48000
fluid.gain = .2
fluid.polyphony = 256
fluid.cores = default
fluid.periods = 8
fluid.periodsize = 512
fluid.reverb = yes
fluid.chorus = yes
fluid.reverb,roomsize = .61
fluid.reverb.damping = .23
fluid.reverb.width = .76
fluid.reverb.level = .57
fluid.chorus.number = 3
fluid.chorus.level = 1.2
fluid.chorus.speed = .3
fluid.chorus.depth = 8.0
fluid.chorus.type = 0
mt32.romdir = .\mt32
mt32.reverse.stereo = false
mt32.verbose = false
mt32.thread = false
mt32.chunk = 16
mt32.prebuffer = 32
mt32.partials = 32
mt32.dac = 0
mt32.analog = 2
mt32.output.gain = 100
mt32.reverb.mode = auto
mt32.reverb.output.gain = 100
mt32.reverb.time = 5
mt32.reverb.level = 3
mt32.rate = 44100
mt32.src.quality = 2
mt32.niceampramp = true

3. case may look like case 1 or 2, but eXo adds the following piece of information regarding the midiconfig line (so in this case, DosBox pure should not totally disregard the midiconfig line, just if it's left empty):

          midiconfig: Special configuration options for the device driver. This is usually the id or part of the name of the device you want to use (find the id/name with mixer/listmidi).
                        Or in the case of coreaudio, you can specify a soundfont here.
                        When using a Roland MT-32 rev. 0 as midi output device, some games may require a delay in order to prevent 'buffer overflow' issues.
                        In that case, add 'delaysysex', for example: midiconfig=2 delaysysex
   

Hope you can use this information. I will try and report back if the error disappears if I delete the midiconfig line, so we can know for sure that this is the issue here.

[SiriusVI87]

Ah, you're using a .conf file. Notice how your .conf file sets the midiconfig option of the [midi] section to an empty value. The settings in the .conf file take precedence over the core options. You have to do one of these:

• Remove the line midiconfig= from the .conf file to use the core option
• Change it to something like midiconfig=X:\path\to\MySoundFont.sf2 to fix playback with a .SF2 SoundFont
• Change it to something like midiconfig=X:\path\to\SomeMT32_Control.rom to force using MT32 emulation with the given ROM

Hey quick addendum to my previous post: I just wanted to confirm that deleting the midiconfig line works. The error is gone and sound works like it's supposed to. the section of the config looks like this now:

[mixer]
nosound=false
rate=44100
blocksize=1024
prebuffer=20
[midi]
mpu401=intelligent
mididevice=default
[sblaster]

Now, what would be really great is if DosBox Pure could be updated to ignore the "midiconfig= " line, if nothing comes after the "=". That would save me from editing all the .conf files.

PS: Sorry, I accidentally closed this issue and had to reopen it.

[SiriusVI87]

Update:

For now I have replaced all the .conf files with edited ones in which the "midiconfig=" lines are deleted. Everything is working fine with this workaround.

IMPORTANT UPDATE: the new "DOSBox Pure 1.0 Preview 1" version breaks everything for me. None of my games work anymore. I have created a separate issue for this.