MT-32 Buffer Overflow and Checksum Errors

[Qbix]

have you tried getting a recent SVN build of DOSBox and enabling the special mode that adds delays to prevent the MT32 buffer overflow problem as I posted above ?

[Collector]

@ laffer: You should be fine. It is much like turning the Turbo switch off and back on again, which is what Sierra used to recommend as a work around for the speed related "Unable to initialize your audio hardware" SB driver error. However, give Qbix's suggestion a try.

[laffer]

I'll try that. The thing is I'm unfamiliar with what a SVN build is, but I'll google it

[Collector]

An SVN build is a developmental build. DOSBox is under continual development between releases. SVN reflects the latest code and includes bug fixes/features/code changes that may make it into the next version of DOSBox. In this case, how DOSBox communicates with an MT-32.

There are some SVN builds that include extra features that will not be included in the official builds fro various reasons, such as 3dfx voodoo chip emulation, built-in MT-32 emulation, printer support, port pass through, etc.

Try a plain vanilla build.

http://www.emucr.com/2011/04/DOSBox-svn-r3692.html

[Qbix]

Here is the new description of the midiconfig parameter

Code: Select all

# midiconfig: Special configuration options for the device driver. This is usually the id of the device you want to use.
#               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
#               See the README/Manual for more details.

The status window of DOSBox should tell you that it is activated.

[Collector]

I just realized that the SVN does not generate a new conf if a DOSBox-SVN.conf already exists. The SVN that I just downloaded yesterday was using an SVN conf from last fall.

[beigemore]

I was thinking about throwing together some sort of picture guide so people that don't own an MT-32 can see and more easily understand what is required to connect one. It's a mess of cables, but totally worth it for any PC game that supports it. I used to have issues with the older versions of DOSBox using the MT-32, but I recently tried a build from May 25th with a Roland MIDI-to-USB adapter and it worked amazingly well. There are still some games I've had issues with getting MT-32 support to work with in both DOSBox and on a real computer, such as Legend of Kyrandia and Arena. I think I also had some issues with 4D Driving/Stunts in DOSBox, but I don't have the MT-32 out to verify at the moment. The build I used was ykhwong's at http://ykhwong.x-y.net/. With that said, I can never seem to get MT-32 emulation to work with any release of DOSBox that says it supports it -- guess I'm just dumb in that manner, but hearing demos of it on youtube makes it sound awful compared to the real thing.

[MusicallyInspired]

The official DOSBox builds don't have MT-32 emulation. Only custom builds made by others do.

[Collector]

Ykhwong's build does have Munt support, but you still need to have the ROMs for it to work. As far as the YouTube examples, it may be from earlier builds of Munt before it got as close to the real thing as it has. It might be that the ones you found also did not properly configure the games to use MT-32 sound.

[beigemore]

Yeah, I've had the roms since back before Canadacow got the first cease and desist stuff from Roland. I've got them sitting the root of the DOSBox folder. When I try to set the MIDI device to MT-32, the status window says:

MT32:Couldn't find control files
MIDI:Can't open device:mt32 with config:.

I normally have the midiconfig parameter in dosbox.conf set to 1, since that's my USB-to-MIDI adapter ID. MT32_CONTROL.ROM is 512kb, as is MT32_PCM.ROM. Searching Google for either of those error messages or where the exact location the rom files need to be placed hasn't turned up any results at all, except for one random forum post I found suggesting the files go in the DOSBox root. Typically these issues wouldn't be a big deal, but I'm having a hard time finding any real information.

[Collector]

What are your [midi] settings?

[beigemore]

What I'm doing is loading DOSBox, and then going to Sound -> MIDI -> Device, and choosing the MT-32 option using ykhwong's latest SVN build.

Code: Select all

mpu401=intelligent
mididevice=default
midiconfig=
mt32ReverseStereo=off
mt32DAC=auto
mt32reverb.mode=auto
mt32reverb.time=5
mt32reverb.level=3

[Collector]

Try changing mididevice=default to mididevice=mt32

[beigemore]

Getting the same error message as before.

[Collector]

Perhaps your ROMs are bad. Do a Google search for replacements.