The typical setup would be to connect the midi side of um one to the retro pc via the sound card mpu401 uart. You will need an adapter from db15 to din. The um one will then send the midi to the device you connect by usb.
For mt32 you will need softmpu tsr or isa card that provides hardmpu support. This won’t support custom samples unless it’s a mt32 or munt on the usb side.

If your intending to connect the usb side to the retro pc I don’t think there is driver for win9x

Pickle wrote on 2024-01-18, 15:25:

The typical setup would be to connect the midi side of um one to the retro pc via the sound card mpu401 uart. You will need an adapter from db15 to din. The um one will then send the midi to the device you connect by usb.
For mt32 you will need softmpu tsr or isa card that provides hardmpu support. This won’t support custom samples unless it’s a mt32 or munt on the usb side.

If your intending to connect the usb side to the retro pc I don’t think there is driver for win9x

This is what I was afraid of. I will google and yandex for usb drivers and see if I can come up with anything. Another option is to use the midi ports on a Sound Blaster Live! Drive or the PCI-bracket daughter board and hope that doing so works in Windows 9x. I have done it with an Audigy drive in the past, but I can't remember if I was using Win98, XP, or 7 when I did that. Whichever OS it was, I had games sending midi data to the MT-32 that way. The UM-One, if there is no driver, will probably be reserved for the main Win 10 PC. I used a generic usb midi cable with WIn 7 in the past.

Serdashop also has an adapter for game port db15 to din
Softmpu can output over the serial port and serdashop also has an adapter from serial to din.
In windows Roland made a midi driver to serial

I’ve used these option to send midi over serial t the mt32-pi

Are pci cards your only option?

Pickle wrote on 2024-01-18, 17:37:

Serdashop also has an adapter for game port db15 to din Softmpu can output over the serial port and serdashop also has an adapt […]
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Serdashop also has an adapter for game port db15 to din
Softmpu can output over the serial port and serdashop also has an adapter from serial to din.
In windows Roland made a midi driver to serial

I’ve used these option to send midi over serial t the mt32-pi

Are pci cards your only option?

I considered softmpu, but I have games which don't work with EMM386.I have been looking at my options over at serdashop. The idea of using a serial port is neat. Interestingly, my 486 has options in the bios concerning midi/serial. As for my slot options, unfortunately there is only one ISA slot in the Windows 98 PC and it is occupied by the AWE32 CT2760. I know that there is a patch for Sierra games so make them use UART midi, though I believe that Ultima VII and a few other games still require an intelligent-mpu option. I often wish I could buy an Orpheus II card or was able to grab an AWE64 Legacy when they were available.

yeah thats difficult with on isa slot. Im using picogus v2 with its hardmpu support otherwise its softmpu. But that would require you to remove the awe32.
heres another option im using for mt32 emulation. but it still needs something to provide the intelligent mpu support:
https://github.com/scrapcomputing/WavetablePi

I put one of these on the picogus and i have hardmpu support with mt32 emulation built in. It can also run soundfonts. (its another form of the mt32-pi)
I have a similar win98 system like you with a awe64. I use a chill and phil adapter on the db15 with a WavetablePi. But im mainly running wing command and microprose games for mt32 which work with softmpu.
But if it didnt i could use the picogus in the 486 system, so im covered either way.