Typically less-than-optimal RAM on a GUS would result in multiple instruments being mapped to the same patches, not unmapped/missing instruments.

For testing purposes, I've found that I can run the tracker style music in jazz through the GUS sbos software soundblaster emulator and it plays all the correct samples, albeit low fi and fuzzy since in sound blaster mode I assume the samples aren't being loaded into the gus ram and processed on the gus like they would if the game were treating the card like a gus. This does help confirm to me though, that I probably don't have, for instance, a broken trace on the card leading to the speaker output...

New update, doom and rise of the triad seem to work great in Gus mode. I also think I fixed my Boppin issue through a combination of selecting lower quality playback and fewer simultaneous sfx. So it's really just the Epic games that very noticeably truncate or don't play samples at this point. I'm sure they all have the same sound driver, and I guess they all load their own custom samples onto the Gus rather than using the Gus default sample set.

I have a hunch there is a resource conflict issue behind this somewhere. I'll try the card in another open slot and fiddle with the settings again.

There isn't a such thing as a version of prepgame for the gus max, right?

I have noticed something similar occurring with Epic Pinball and occasionally tracker music (via Scream Tracker 3).

For example, in Epic Pinball, if I play a couple tables and then return to the main menu, sometimes the sound effects or parts of the music will cut out. This has happened on multiple systems with multiple GUS cards. It seems to occur more readily with certain DMA assignments, so my suggestion would be try different hardware settings.

Another thing I would try is testing the memory you have installed, just to verify it's all working correctly.

EDIT : Forget about my questions. Jazz and OMF use their own samples. Patchset is irrelevant,

Are you using only the stock, Gravis provided patchset ?

Did you install Propatches or other third party patches ?

I went to town tonight removing other isa cards, trying the gravis in different slots, different base, irqs and dmas. Different settings on the CD drive jumpers. Deleting and reinstalling the driver and utility package from scratch. Sadly nothing changed my results and I always seem to have the audio dropouts.

I also noticed I have the dropouts even through the sbos emulator in a small handful of games, so I guess it's not entirely an Epic games or mod playback issue.

Btw, in general for anything that uses the gravis provided samples, I'm just using the default sample set and not the pro patches or anything else unusual.

I have purchased a chip extractor so I can try to take the extra 512k ram chip out. My hope is that this is bad ram that is recognized as existing on the card, but which does not appropriately read/write the samples that are allocated to it. Hopefully simply having the Gus be recognized that it is in 512k mode instead of 1mb mode will end the drop outs. Failing that, I'll reconfigure another computer to test it out there, and if that gives the same results then I guess the card has something wrong on a hardware level such as a flakey GF1 or crystal, which would be beyond my ability to repair.

It might help if you posted the system settings of you GUS MAX and your system specs.
A few things to check are whether you are using high DMA channel for the GUS (4 through 7) and if you can change delay settings of your ISA slots in the BIOS and maybe also the ISA clock setting.
Try setting the DMA channels to 0 and/or 1 and increasing the delay of your ISA slots (if that is the proper term, I'm not at a computer that has ISA slots right now).
You could also try removing the extra memory from the GUS MAX and try it with just the 512kB onboard RAM.

CHiLL72 wrote on 2024-07-26, 12:16:

It might help if you posted the system settings of you GUS MAX and your system specs. A few things to check are whether you are […]
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It might help if you posted the system settings of you GUS MAX and your system specs.
A few things to check are whether you are using high DMA channel for the GUS (4 through 7) and if you can change delay settings of your ISA slots in the BIOS and maybe also the ISA clock setting.
Try setting the DMA channels to 0 and/or 1 and increasing the delay of your ISA slots (if that is the proper term, I'm not at a computer that has ISA slots right now).
You could also try removing the extra memory from the GUS MAX and try it with just the 512kB onboard RAM.

Ah thanks, as a matter of fact, I have some good news. I put the GUS Max into a completely different PC today and it played the EPIC game music just fine. I also used the same OS, autoexec.bat and GUS install from the problematic pc for the test (I swapped my compact flash card "HDD" from the problematic PC over to the second PC for the test), so it seems unlikely from that result that I have faulty ram on the card or some other kind of hardware fault on the card itself, or that I have a faulty installation, and it is then most likely that I have a resources conflict with the original PC I was putting it in. I have put the GUS Max back into the problematic PC as that is the PC I most want to use it in, so I am continuing the troubleshooting process.

As far as the problematic PC, it is somewhat eclectic, I've included some specs from HWINFO here https://imgur.com/a/kAb3tJn . The motherboard is a 386/25 motherboard by Standard Computer Corporation from 1990 and I have not been able to find it documented online. The cpu has been upgraded to 50mhz with a cyrix 386->486 upgrade cpu. It has 3.5" and 5.25" floppy drives as well as a 2X Mitsumi CDrom drive that requires its own ISA card (though I suppose I could attach it to the GUS Max now). I don't see any options related to ISA slot/bus settings in the bios. By way of context, this is my childhood PC from 30+ years ago, all of these upgrades to the memory/cache/cpu and adding the mitsumi cdrom drive ISA card were done back then. I also used the same model of GUS Max with this machine 30 years ago without the audio problems I have right now. So I ask myself, what is different between the current state of this machine now versus 30 years ago and there are the following differences:

-30 years ago the PC had a 500MB IDE HDD, these days it uses a modern Startech IDE-compact flash adapter with a 2GB CF card

-In order to boot from the CF adapter, I needed to add the XT IDE bios to an ISA lan card (the same lan card existed in the machine 30 years ago)

-If the GUS Max came stock with only 512KB of ram and it was up to the user to add the rest, then my GUS Max card 30 years ago probably just had the 512KB of ram instead of 1MB. (Theory, maybe the 386 motherboard is fast enough to utilize 512kb of GUS samples in realtime, but not fast enough to utilize a full 1MB of samples? But this may be unlikely as I tested out a replica GUS PNP card in this machine 6 months ago that I think loaded the 1MB samples, and its sample playback worked ok)

I've tried a wide variety of permutations for IRQs and DMAs. I currently have the GUS variable set to 240,3,3,7,7 but I know I have tried DMA 1, 5, and 7 and IRQs 3, 5, and 11 and probably others as well. I've also tried the card on base 220 with various DMA/IRQ combos.

I used shadow ram with the xtide bios that was on my ISA lan card and I'm pretty sure that improved the drop outs a bit. I still have them but the amount of drop outs is not as much as the clips I recorded. Really starting to think the drop outs are related to the ISA bus speed of this PC and hoping that dropping the Gus Max onboard ram from 1MB to 512kb will be the solution to get rid of them.

I took the extra ram out. No change in my audio drops with some games. Is there an ini file or other thing I need to edit to ensure games treat the card as having 512k of RAM instead of the 1MB it had when I first installed it?

If the GUS Max works in another PC, I don't see why any of its onboard RAM would be "bad/defective" only in one specific PC. A 386 should be fast enough to play the tracks (the GUS is doing the mixing) and all of the songs in OMF 2097 are smaller than 256KB anyway, AFAICR. You could try playing the ripped songs (S3M files mostly, AFAICR) in a standalone tracker instead of the game to see if the issue still manifests itself.

I see also less potential connection between issues potentially due to ISA bus speed and the amount of RAM on a GUS of any kind. RAM on a GUS is not directly mapped to the ISA bus.

Honestly, to me this either looks like either a weird incompatibility or something on either the motherboard or the GUS Max (or both) being slightly marginal/out of spec.

Of course, I could be wrong.

Just a thought, can you try with the L1 cache on the Cyrix processor disabled ?

I agree, the bad ram idea is completely out the window now.

Good idea to try the epic tracker music in some tracker playback software, I'll try that to rule out an incompatibility with the epic software in particular (I think the Gus really seems to be working in other stuff like Doom and Boppin, and midi playback and quirky sbos sample mapping). For what it's worth I've noticed the audio drop outs don't happen in the same places/same samples of the Jazz/Omf/ Epic Pinball music each time.

darry wrote on 2024-07-30, 05:27:

Just a thought, can you try with the L1 cache on the Cyrix processor disabled ?

I was playing around with this last night and realized the drop outs seemed to be slightly lessened if the l1 cache was turned on. Not sure why this would be helping though.

I'm still thinking along the lines of what is different with this PC compared to 30 years ago when essentially the same configuration worked... Could using the XTide bios play a role somehow? I need it to run the system on CF, but I guess I could buy a small HDD and test the system with that in order to take XTide out of the equation.

I tried playing the Jazz and OMF music, as well as unrelated mod files with Impulse Tracker and ran into similar playback issues as the epic games. If I were to describe the state of things right now, it seems music that uses the official gus standard samples (Doom, Boppin, GUS midi player, Raptor, many games where I rely on SBOS for soundblaster/adlib music) work fine, but stuff like tracker music that wants to load its own samples provides the skips and drops.

I guess there's a hardware conflict, not sure what to do though. I've test configured the gus with so many permutations of baseport, dma, irq, I don't know what to check in that area that I haven't already.

As I did not see it mentioned whether you tried it: did you try changing (increasing) the wait states for the ISA bus in the BIOS settings? And did you try any setting with just DMA channels 0 and 1?

CHiLL72 wrote on 2024-07-31, 13:43:

As I did not see it mentioned whether you tried it: did you try changing (increasing) the wait states for the ISA bus in the BIOS settings? And did you try any setting with just DMA channels 0 and 1?

Thanks for trying to help 🙂

I do not see any settings in this pc's bios to make adjustments to the isa bus.

I've tried Dma 1 and 0 as Gus variable settings in the autoexec and still had the playback issues. I also just tested every Dma option in the one must fall options (1-7) and all of them have the drop outs.

I haven't fixed my issue yet, but I did discover and solve another issue.

If you have the Gus irq and recording irq set to the same value in the ultrasound variable , this seems to cause a few idiosyncratic problems in games when using sbos. Namely, in skyroads the music and sfx will play but the game will freeze about one second after the first sound effect plays every time. Just adding this here to be found by future users.

I found a reference to someone else having GUS playback skipping notes. Seems as some suggested it could be related to ISA bus speed, which I haven't been able to figure out a way to adjust on my motherboard

From here: https://nerdlypleasures.blogspot.com/2016/10/ … ultrasound.html

Some games will have skips or lag in the GUS playback if the ISA bus speed is set to the default, 8.25MHz, but setting it to 7.19MHz in the BIOS seems to eliminate most problems. Setting it to 6.6MHz is required for smooth playback in the DOOM games and One Must Fall 2097. Other people get their Utrasounds working fine without needing separate DMA and IRQ settings or lowering the bus speed. I do not know if this is an issue particular to the ACE or to the SiS motherboard chipset (SiS 85C471 + 85C407) I am using.

[The GUS OMF skipping notes issue is a weird one. I tried lowering the bus speed to 6.6MHz and that seems to have fixed the issue. I have posted a new recording, so feel free to compare. It seems like 6.6MHz is the right bus speed for my card. I don't know if this is just my card being weird or an issue with the ACE, but I have never read anything about GUS cards being especially sensitive to bus speed.

dukeofurl wrote on 2024-08-07, 00:47:

I found a reference to someone else having GUS playback skipping notes. Seems as some suggested it could be related to ISA bus speed, which I haven't been able to figure out a way to adjust on my motherboard

That seems a likely culprit if you've eliminated all the other possibilities, especially with the card itself.

FWIW, the slowest system I've used a GUS with was a 386 DX/40. For the most part I don't any obvious skipping or audio drop-outs, other than the aforementioned cases with Epic Pinball.