... I would reboot, to be sure the modules are unloaded at first, then load them with this command.
[root@localhost ~]# modprobe snd_es81xx io=0x220, irq=5, dma=1, dma16=5, mpu_io=0x330, midi=0x388 <Enter>
After which, try alsaconf again, to see if it now finds the card and sets it up properly.
Reboot; modprobe -r; dma=1,dma16=5 or dma1=1,dma2=5... alas; no success yet. I have been swapping hard drives and comparing operating systems on this machine today, and now have the following to report:
1) The Slax 6.1.2 live CD seems to make use of OSS for its default sound system.
2) Slax has sound output only initially - after several minutes of operation, its sound system fails; mplayer/kplayer/vlc all lock up and refuse to either play anything or even exit properly (xkill is required), and YouTube crashes FireFox completely only a second or so after it begins playing.
3) No sound was obtained from any other modern distro (although I haven't bothered with some of the older ones yet.).
4) Windows 98SE has been installed successfully onto another hard drive - its soundsystem is functioning properly.
5) Windows indicates the same IO and DMA port parameters; however, it also indicates one additional
port address that does not seem to be mentioned in any of the linux documentation: an ES1869 Control Interface (WDM), at 0x0250-0257 (in Basic configuration 0000, and with "Use automatic settings" enabled.).
By the way; as a completely-unrelated aside, I found your user icon (of all things!) to be of some interesting use today. I have the old Armada 1750 machine set up on a coffeetable beside my Acer TravelMate 2203LCi - a more 'modern' 2.80GHz Celeron D unit with 1.25GB of DDR memory, and an ATI Mobility Radeon 9000 IGP chip for video. Both laptops were running 2010 E17 Final (each fully updated) at the time, and happened to be displaying the same forum page - with your user icon. I noticed that one seemed to be animating faster, so I timed them by counting sixty 'eyeglass-raises' each against a stopwatch. The results worry me:
Compaq: 66 seconds;
Something must surely be wrong, somewhere. This same Acer had performed properly previously, with Minime 2008 installed... why is it so slow now, with 2010? How could it possibly be, that an 'obsolete' 400MHz P2 machine with only Mach64-based video and a mostly-missing BIOS, actually manages to browse (and behave overall) considerably
faster than a machine with more modern video, four times the amount of RAM, and a CPU that is more than seven times speedier?
All the more impetus to restore the older unit to proper service, I think...