Need more information. What OS? Soundcard? Drivers?

maybe speed problem. try to turn off the cache

It is a speed issue. U6 sound effects (not music,) was done using the PC speaker (like Ultima 1-5 did.) It was also written with a 386 in mind (processor speed of 16Mhz IIRC.) Running on a Pentium, your speeds are too fast for the speaker sounds to play correctly. There was a patch to slow down the sound effects, but I was never able to get it to work correctly. It slowed things down far too much. If I remember correctly, the author told me that it was designed on a 486 system, and on Pentium systems the loop multiplier didn't work right, resulting in too much slow down. The only way I got the sound working right was to move it to my main (modern,) system and run it through DOSBox.

Increase IO wait states. Especially 8-bit IO wait states as FM music needs long enough delays between IO writes.

Another suggestion is to use a sound card with OPL3 chip, as they can be accessed faster than OPL2 chip, so that may remove FM being garbage problem.

badmojo wrote:

Need more information. What OS? Soundcard? Drivers?

DOS 6.20, Sound Blaster AWE32, standard Creative driver 1.0.

I thought you were talking about the sound-FX not the music. The music worked fine on my 1.4Ghz system with AWE32 and no ability to adjust the wait-states of the 16/8 bit ISA slots. Couldn't get the FX working so gave up and moved it back to my modern system. 🙁