Hi people here at vogons,

I feel like I did everything I could do to fix a problem I have playing back module music with a gravis ultrasound classic using hardware mixing. So I need help to diagnose and hopefully resolve that issue. To describe the problem I did some recording that I'll attach to the thread highlighting the issue (all on the same computer: broken_*.mp3 is done with cmod gus hardware mixing and ok_*.mp3 is done with iplay gus software mixing). It is somewhat random, in that every music affected will not always sound the same, but the distortion will differ depending on state of affair (irq, dma, memory manager, previous module played, moon phase and what not). Some demos that use gus hw mixing are affected by this. The problem seem less apparent with other players that support hw mixing like openCubic Player or gusmod, but something yet sound not quite right, I would like to continue using my favorite player since day one, capacamod, it used to work great, unfortunately I did not know what changed since it started playing like this.

So what I did so far, I swapped the gus classic with a gus max. Did try all the different irq/dma settings. I also removed other hardware in the computer (sb1.5, voodoo2 and changed the matrox g450 for some s3 or ati). I'm not very good with pnp bios, but I did try change isa irq to pnp/icu thing to no success, but if you had anything to recommend, it's always easy to test.

Here is the most precise description I can do of the setup, but if you think I omited anything you deem important I'll be glad to provide further information: The computer is a pentium 166mmx with award modular bios v4.51pg. Chipset is ALi m1541 aladdin V on Asus P5A motherboard (system bus speed of 66mhz). Video is a matrox pci mga450 32mb on irq 14 with a voodoo2. There is 128mb of ram. Hard disk is a 32gb compact flash on an pci controller Promise Ultra133 TX2 on irq 15 running freedos 1.2. NIC is a 3com 3c905b-tx fast ethernlink xl 10/100 on irq9. The sb1.5 is at a220 i7 d1 and the gus irq is 11, midi is 5 playback and record dma are 3. Note that I cannot reproduce the problem playing midi.

To make thing more interesting for those who take the time to read my thread (and because I enjoy photography) here is a picture of the setup: