The Diamond Monster Sound II MX300 is a PCI card. If memory serves, reserving those resources in your BIOS will not work, as this actually meant for non PnP ISA sound cards. I'm not an expert with this particular card but, check under your Device Manager that the Vortex Sound Blaster emulation is enabled and that the relevant resources have been assigned correctly (after undoing the "reserve resources" settings in the BIOS setup).
Verify this to the Set Blaster environment variable (in your Autoexec.bat file) to ensure that it matches the settings under Windows.
It's been some time since I've played with Windows ME, so I'm not 100 % sure what you can update in your Autoexec.bat file but, I know you are limited to what can be loaded from there.
Personally, I would fall back onto Windows 98SE, since you can then boot into MS-DOS mode as well (unless you patch your Windows ME).

I reserved the resources in BIOS so that the BIOS or OS PnP wouldn't assign it to something else, that way I could manually assign them to the SB Pro emulation. Checking AUTOEXEC did not occur to me, the IRQ and DMA values may not be changeable because of the BLASTER environment, I will look into this. I would revert to Win98SE but native support for USB mass storage has spoiled me too much, and I don't need true DOS on this build.

appiah4 wrote:

I reserved the resources in BIOS so that the BIOS or OS PnP wouldn't assign it to something else, that way I could manually assign them to the SB Pro emulation. Checking AUTOEXEC did not occur to me, the IRQ and DMA values may not be changeable because of the BLASTER environment, I will look into this. I would revert to Win98SE but native support for USB mass storage has spoiled me too much, and I don't need true DOS on this build.

The reason why resources are reserved in the BIOS, is for non PnP devices that neither the BIOS or the OS can detect (i.e., you are manually "telling" the BIOS/OS that those resources are already assigned to a non PnP device) which, in the first place, is to prevent a resource conflict. By reserving those resources, you are actually "telling" Windows not to assign those resources to your sound card. If I were you, don't reserve those resources in the BIOS and then go into Windows and manually assign the resources (if you are not satisfied with the default values, which are normally IRQ5 & DMA1).
Just take note that a Sound Blaster Pro doesn't use a high DMA channel which means that no games will utilise it. So, whatever the second DMA channel is being used for, it shouldn't impact the functionality of the emulation and I would therefore just use the default value that it assigns for you.

If you want USB mass storage device support under Windows 98SE, just download the latest Unofficial Windows 98SE Service Pack 3.x, open the archive and within that archive, open the *.CAB file (you can use a utility like 7-Zip). Within there is a file called "USBStack.exe", which you can just run - this will then install USB Mass storage support for you.
PS: There is no need to install the Service Pack - you can just run the file that I mentioned. However, I normally install the Unofficial Windows 98SE Service Pack 2.1a and then separately run the "USBStack.exe" file.

I went into the BIOS and reset the whole PNP/PCI configuration to Auto, rebooted, and the Sound Blaster Pro emulation moved from 5/1/3 to 9/1/3 and Device Manager still did not allow me to change it at all, so I reset it to reserve IRQ 5, DMA 1/3/5 and it reverted to 5/1/3. I checked autoexec.bat and unsurprisingly BLASTER was set to A220 I5 D3 T4, so I changed that to D1, smirket smugly and rebooted. The computer turned back on and it was still 5/1/3 and autoexec.bat had been changed back to A220 I5 D3 T4. What gives, I do not know. I went into settings for Doom and set it as IRQ5 DMA 3 and it works flawlessly. Duke3D setup makes a second, 16-bit DMA setting mandatory so I set that up as 5 and it also worked fine, as the SB Pro Emulation driver does not really use a High DMA apparently. So at the end of the day, moving that driver to a regular SB setting was not possible but at least it works. If anyone knows how to actually get this to run as IRQ 5 DMA1 HDMA5 let me know.

Thinking off the top off my head - Under the BIOS, where you change your PNP/PCI configuration data, there is usually an option to "reset configuration data" (or something similar).
You could try to set everything to auto, "reset configuration data", save and exit the CMOS setup.

If that doesn't work, try only to reserve IRQ5 but, not your DMA channels (it doesn't seem to make any difference whether you reserve your DMA channels or not) and "reset configuration data" again.

The fact that your SET BLASTER statement does not specify the high DMA channel (which is with the "H" parameter) tells me that it isn't using it. But, I understand that you would like your (Sound Blaster) low DMA channel to run from DMA 1.
However, based on what you mentioned above, DMA channel 1 is being used for something else, whereas DMA channel 3 is actually being used for your Sound Blaster emulation (hence, why you are not able to change your Sound Blaster DMA channel to 1).
Might be a good idea to dig into this sound card's documentation to establish what the other DMA channel is being used for.

Unfortunately, I'm not very familiar with this particular sound card. With Sound Blaster Live! cards, Windows will update whatever settings you have to a configuration file (called CTSYN.INI) and this is what DOS will also read (and at the same time also update the SET BLASTER environment variable). Unless, you manually update that file and make it read-only.

There are some threads on Vogons related to this sound card - one might provide some insight as to how to change your settings.

EDIT: As a last resort, try moving your sound card to another PCI slot (with everything set to auto and after you've "reset configuration data").

use auto configure #7 this allows you to set the desired resources for the card.

Under pure DOS you want the Vortex 2 to reside on an upper IRQ like 10, and let the au30dos.com file do its thing on one of the normal sbpro IRQs 5 or 7. The driver is IRQ agnostic and should intercept whatever IRQ you chose in games. It defaults to IRQ 7 and DMA 3. Make sure the set BLASTER=A220 I7 D3 T4 the windows drivers like adding a space in the string at the equals sign and causes some games not to detect it, like Quake.

Hope this helps