WinXP comes with a fairly nasty SB emulation built into NTVDM (DOS virtual machine). Your 1st challange is to find out if you're actually using VDMSound or if the MS driver is being used instead? Maybe VDMSound is never being used given the sounds are alike (with/out VDMSound being loaded). I run Win2K so no next to nothing about the built in SB emulation layer of WinXP.

ok thanks

How to I work out whether the Microsoft emulation or the VDMsound emulation is being used then?

Disable XP SB emulation in autoexec.nt.

You mean by putting A0 as the base port address?

If I do that won't it also cause a problem for the game I am trying to run as the blaster environment variable will be set wrong?

I have tried putting SET BLASTER=A0 as the blaster variable to disable the XP emulation.

However, I get no sound in the game. This doesn't surprise me as the game is probably using A0 as the blaster address.

However if I then try to change the Blaster variable from within my dos session, I still get no sound, and after quitting the game the blaster variable has automatically reverted to A0.

Therefore I'm not quite following how I can disable the XP SB emulation whilst still succesfully using VDMSound.
cheers

Patrick - I am not sure if this will work, but I think you can do this:

1) In AUTOEXEC.NT do the "SET BLASTER=A0" trick. This should prevent the NTVDM SoundBlaster emulation from working.

2) In the VDMSound LaunchPad, go to "Advanced..", then "Troubleshooting" tab. Enable "Diagnostic log" and log Everything for the VDMSound SoundBlaster emulation. You might also want to enable logging for all the other stuff in there.

3) You can also try to add a "SET BLASTER=some valid values" in the "Custom configuration" field of the "Troubleshooting" tab.

Now run the game, and see if you can locate the log-file. I am nor sure where VDMSound creates the file, so go crazy with the search function & "modified in the last 1 days". If the game is going through the SoundBlaster emulation provided by VDMSound, you should see *something* in the log.

When using the "Run with VDMS" shortcut, the environment variable BLASTER is set via VDMS.INI in the VDMSound directory.

You can verify this by using "Run with VDMS" on command.com in the system32 directory. Run it, type in SET and you should see: "BLASTER=A220 I7 D1 H5 P330 T6"

Whereas just running cmd.exe, autoexec.nt uses: BLASTER=A220 I5 D1 P330 T3

I have created the VDMS log file and it does say that the SB emulation was initialised. It is full of performance warnings about DMA updates too infrequent.

Is that an indication that VDMSound is running correctly then?