Just add the line stereo 1 in the z.cfg file.
Ah, okay, I'll go try that; I was wondering where there might be a "reverse stereo" option, and was a bit puzzled that the setup program didn't include it, unlike most DOS games from the era (such as
Dark Forces and
Master of Orion, the other two DOS games I play like crazy)
The problem here is the Sound Blaster Pro cards. There were no proper left/right standard for those. And while you set it as Sound Blaster 16 in the setup program, there must be something that makes the game think it's a Sound Blaster Pro card. Most newer card that were released after DOS that offered SB emulation have SB Pro emulation. Only exception to this (as far as I know) is SB Live! which had SB 16 emulation.
Yep, that's what I'd drawn the conclusion of, as most programs, as I mentioned, had the option of reversing stereo channels. And yeah, the computer in question is using the cheapie AC'97 integrated audio.