I don't know if this will help, but I have the same result with my MT-32 first version.
4D Boxin MT-32 Version 0
4D Boxin MT-32 Version 0
4D Boxin SB16
4D Boxin SC-88 Pro using SC-55 Mapping

Hi, thank you very much for your answer, it sounds exactly as my MT-32 OLD sounds, so probably the reason is this game was programmed for use with MT-32 NEW, it's strange because 4D Sports Boxing is from the early 90's but I don't know...

When you launch the game, does the MT-32 send messages about an arithmetic overload or anything of the sorts?

raymangold wrote:

When you launch the game, does the MT-32 send messages about an arithmetic overload or anything of the sorts?

Not in my case and I have the same "issue". I think it's a bug in the game, not an actual iassue with the MT-32 itself.

You could test in DOSBox with MUNT?

philscomputerlab wrote:

You could test in DOSBox with MUNT?

The SC serie Roland does not do this. I think it's a design flaw in the game.

The problem is that the game tries to set the pitch bend range using an RPN midi message, which I don't think was defined by the midi-standard at the time of the MT-32 (old). It is supported by the CM-32L and later devices though, and possibly on the MT-32 (new) as well.
On the MT-32 (old) the pitch bend range will stay on the default 12 semitones, instead of the intended 1 semitone, resulting in some weird tones when pitch bend is used.

They likely had a LAPC-I in their machine.

perc wrote:

The problem is that the game tries to set the pitch bend range using an RPN midi message, which I don't think was defined by the midi-standard at the time of the MT-32 (old). It is supported by the CM-32L and later devices though, and possibly on the MT-32 (new) as well.
On the MT-32 (old) the pitch bend range will stay on the default 12 semitones, instead of the intended 1 semitone, resulting in some weird tones when pitch bend is used.

Reviving the thread because I now own both Revision 0 and Revision 1 MT-32, and indeed, the Revision 1 seems to support the semitones.

Compare here :

4D Boxin MT-32 Version 0
4D Boxin MT-32 Version 1

As perc mentioned, "4D Sports Boxing" attempts to set a bender range value for several parts using RPN #0, which isn't a method supported by the older MT-32 units. This is a function of the game's (older) MT15.DRV driver.

"4D Boxing," on the other hand, has a newer MT15.DRV driver that uses the SysEx method for setting the bender range, as supported by all MT-32 variants. In addition, the SysEx transfers are "buffered."

So, the easy solution for playing this game with an older MT-32 is to just copy and use MT15.DRV from "4D Boxing."

Hi, thanks to everyone for the help.
Probably I will sell this MT-32 OLD and buy the NEW version.
But I don't understand this:

Cloudschatze wrote:

So, the easy solution for playing this game (4D Boxing) with an older MT-32 is to just copy and use MT15.DRV from "4D Boxing."

Probably you wanted to say "copy and use mt15.drv form 4D Driving"? (the other game of 4D series that use the MT-32 and doesn't have problems with OLD version).

eduedu_123 wrote:

But I don't understand this:

Cloudschatze wrote:

So, the easy solution for playing this game (4D Boxing) with an older MT-32 is to just copy and use MT15.DRV from "4D Boxing."

Probably you wanted to say "copy and use mt15.drv form 4D Driving"? (the other game of 4D series that use the MT-32 and doesn't have problems with OLD version).

No, there's a "4D Sports Boxing," and a "4D Boxing" - variations of the same game. The problem described in this thread relates to the MT-32 driver provided with the former. Here's the MT15.DRV from the latter. Extract it into your game directory, and the older MT-32 will be supported properly.

Ok, now I understand, I ignored this possibility because the version you mentioned has a complete different soundtrack but the file you shared is a driver so it have to work.
This week I'm out of home so I will try it next week and comment the results.
Thanks!

PS: Isn't strange that the Electronic Arts version (that came later than the first version) have a driver for the OLD MT-32 and the first version don't?

Why would that be strange?

Because the Electronic Arts version came after the original version 😜
Any way, it doesn't matter, when I can try the driver I will post the results.

Your answer does not adequately explain why that would be strange. They most likely tested the first version only with the LAPC-I which is far less fussy than the old-type MT-32, then when MT-32 owners complained, they updated the driver to work better with the old-type MT-32 and included that driver in the later version of the game. Tht is what happened in the case of X-Wing.

i've reverse the MT15.DRV of Stunts 1.0/1.1 - so it now easier to read what the code does : UnifiedMT15: Reverse Engineering Project for the Stunts 1.0/1.1 MT15.DRV (MT32 Sound Driver)