Considering that you experienced similar problems with another AWE based card, it is therefore likely that the problem is motherboard related.
The fact that your MIDI & FM music is being cut off, tells me it has something to do with the AWE chip and a possible "conflict".

You could try to play around with the BIOS settings, starting by disabling any "power saving" features on your ports and channels (DMA, IRQ). I presume you are using the standard settings of the AWE card, namely A220 I5 D1 H5 P330 E620 T6?
If your motherboard has memory parity error checking, enable it.
What other cards or peripherals do you have in your system that might potentially conflict with your card and that are not Plug 'n Play?
What environment are you using? Real mode DOS or Windows DOS Box (command prompt)?
What happens when you play back MIDI and/or FM music under Windows itself (just play back a normal MIDI file)? Does the same problem occur?

OK, so after some continued investigation, I believe there may be a couple of different things here.

1. Yes, I do use the standard A220 I5 D1 H5 P330 E620 T6 configuration.
2. I enabled memory ECC function in the BIOS. It changed nothing.
3. The issue happens in pure DOS only. Under Windows I have neither issues with DOS games (those that can work in a DOS box), nor issues with playing simple MIDI files.
4. The other cards I have in the system are a PCI VIA Fast Ethernet Adapter (enabled in Windows only) and a PCI Sound Blaster Live (disabled in all configurations). Both are PnP, and are unlikely to be causing it. The SB Live is invisible in DOS. The Ethernet adapter is visible, but uses different IRQ and different memory addresses. There are no conflits.

Now, it seems that my initial analysis was a bit inaccurate. I think I narrowed the issue down only to some specific games that mess up the FM portion of the AWE card. Specifically, id's DOOM engine games seem to be causing it / affected by it.

There are at least two different symptoms:

1. After playing any DOOM game with AWE32 music option - the FM stops working on the AWE, for all games, until AWEUTIL /S is run again.
2. After playing any other game with the AWE32 music option, with high probability the AWE option in DOOM will be messed up (awful noise plays instead of music, which persists even after you exit the game). Again, running AWEUTIL /S resets it.

If I boot up the PC and play all sorts of games which do not include the DOOM games, it seems that both FM and AWE continue working, without requiring re-initialization.

Therefore, I now suspect that the other card was really just bad, and this issue here is unrelated. I'm still curious if it is just some bug/incompatibility with the DOOM engine games and the way they talk to the AWE, or whether it is a more specific issue, which may depend on the exact card / motherboard / CPU combo.

So I wonder if anyone here who has an AWE card can test it for me. Any DOOM game, including the shareware version should do (I'd use 1.9 to be sure). The test would go as follows:

1. Boot pure DOS, run AWEUTIL /S to initialize the FM synthesizer.
2. Run the DOOM setup program, set the sound to Sound Blaster and music to Sound Blaster. Launch the game. Is music working?
3. Run the DOOM setup program, set the sound to Sound Blaster and music to Sound Blaster AWE32. Launch the game. Is music working? If not - run AWEUTIL /S and try again.
4. Run the DOOM setup program, set the sound to Sound Blaster and music to Sound Blaster (again). Launch the game. Is music working? If not - run AWEUTIL /S and try again.

I believe, but I'm not 100%, that the issue with Doom is indeed a bug. With Doom and Duke Nukem 3D I always reboot the machine after playing, just as a precaution 😀

I agree with Phil and seem to recall this as well.
Easiest way around this is to just create a batch file in your Doom directory that essentially runs Aweutil /s before the game starts and then again after the game exits.

Well, that takes care of one thing then.

I did learn a couple more things from playing around with the machine:

• The AWE64 goes crazy if I try to plug a gamepad (tried Gravis Gamepad Pro). All sound stopped working. I had to take the card out of the slot and put it back in. I vaguely recall it happened once before.
• One of the 3 ISA slots on the motherboard seems to have died. The card would not be recognized at all while in this slot.

Man. That is tough to hear. It is possible that you have a mobo issue as jesolo originally mentioned. That might include a capacitor problem. It is also possible that your power supply itself is not up to snuff. A power-related issue can cause unpredictable problems, and adding the joystick (which would draw more power) is also quite suspicious.

dr_st wrote:

Well, that takes care of one thing then. […]
Show full quote

Well, that takes care of one thing then.

I did learn a couple more things from playing around with the machine:

• The AWE64 goes crazy if I try to plug a gamepad (tried Gravis Gamepad Pro). All sound stopped working. I had to take the card out of the slot and put it back in. I vaguely recall it happened once before.
• One of the 3 ISA slots on the motherboard seems to have died. The card would not be recognized at all while in this slot.

Are you hot plugging that joystick? If so, please don't. I used to do that on my SBPro a long time ago but one day it burned out the port.

The non-working ISA slot is a weird problem. I remember having trouble with the bottom PCI slot on a later motherboard and eventually deciding it had been caused by a weak/bad power supply. It worked fine after I replaced it. I guess when the power is marginal, some slots can end up having better power delivery than others. If you can then I'd try measuring voltages with a multimeter and see if everything looks healthy, preferably measuring at the slot but just measuring at the PSU connectors would still give a good sense of what's going on.
It's conceivable that caps could also be an issue that might affect one slot more than another.
Other than that, all I can think of is if there's some kind of issue with resources being assigned or available to different slots.

shamino wrote:

Are you hot plugging that joystick? If so, please don't. I used to do that on my SBPro a long time ago but one day it burned out the port.

That's interesting. I never thought they would be an issue with hotplugging gameport devices. In my mind I always treated them no different from standard serial/parallel ports. But I will be cautious now. 😀 The funny thing is that the joystick itself worked after the hotplugging, but the audio stopped working until those manipulations I mentioned.

shamino wrote:

The non-working ISA slot is a weird problem. I remember having trouble with the bottom PCI slot on a later motherboard and eventually deciding it had been caused by a weak/bad power supply. It worked fine after I replaced it. I guess when the power is marginal, some slots can end up having better power delivery than others. If you can then I'd try measuring voltages with a multimeter and see if everything looks healthy, preferably measuring at the slot but just measuring at the PSU connectors would still give a good sense of what's going on.

I agree it can be either of these things. Not inclined to try to replace those parts on such an old system, as long as at least some slots work and there are no other issues. However, I will try the multimeter test perhaps.

shamino wrote:

Other than that, all I can think of is if there's some kind of issue with resources being assigned or available to different slots.

In theory, yes, but I would think that with everything configured to PnP in the BIOS, and the card being PnP, it should at least detect it, unless something is wrong electrically.

Anyways, I will continue investigating this, but a bit later. I now want to take this system in a little different direction. That will be in about 2-3 weeks, since it's not physically located in my primary residence. 😉

Well, after a brief venture away from Creative garbage into the realm of proper OPL + daughterboard, I am back to the AWE64, crappy CQM and all... 🙁 The other solution, while allowing for very nice sound, was surprisingly finicky and gave me a whole range of different issues (which will be discussed in a separate thread).

And I learned that Rise of the Triad is another game which has a tendency to screw up the AWE. So it is best to re-initialize it with AWEUTIL before running RoTT as well. Overall, quite a lot of bugs in the EMU8000... Fortunately, AWEUTIL takes care of most of them, resetting the card to a known good state, not requiring reboots.