Sound in the DOS emulator

by Darren Prescott

The main change between the DOS subsystem between Windows 2000 and Windows XP was the addition of sound support; Windows XP emulates a Creative Labs Soundblaster 2.0, which should in theory allow most DOS games to run with full sound effects. Things aren't that simple, though, and a soundcard emulator is recommended.

First off, the inbuilt emulator is configured using autoexec.nt; the file contains a SET BLASTER command (as used in 'real' DOS) to configure the emulator. Unless you have a specific reason to change it, the defaults should suit most games.

The defaults (which you'll need when configuring certain DOS games) are as follows:

Card type: Soundblaster 2 (or just plain Soundblaster - not SB Pro or SB 16)
Address: 0x220
IRQ: 5
DMA: 1
MIDI / MPU port: 0x330

If your game allows you to select General MIDI for music then you should hear music; however plenty of games only support the Adlib and FM synthesizers (such as the OPL2 and OPL3 found on ISA Soundblaster boards). If you're lucky enough to be running an old ISA Soundblaster, then you should be able to run these games (such as the Commander Keen series) and hear the FM music and sound effects. Those running PCI sound cards (such as the SB Live and Audigy) won't hear anything, though - as your soundcard lacks the hardware that FM synthesis uses. To hear Adlib/FM sound effects and music, you'll need a soundcard emulator such as VDMS or SoundFX.

Even if you have an old ISA soundcard, you'll find that some games won't give any audio at all, even if you've set everything up correctly. In some cases, you'll need to use a program called CLI2NOP; in others you'll need one of the following soundcard emulators:

The only decent free soundcard emulator. This emulates a Soundblaster 16 (so you'll get stereo sound effects); it also provides a bridge to the MIDI or FM hardware of your soundcard. The newer versions include an FM emulator. There is a support forum and a compatibility list of known working games. http://www.ece.mcgill.ca/~vromas/vdmsound/

A commercial product, this also includes FM support. SoundFX emulates cards ranging from the plain Soundblaster to the SB 16; it also allows access to the EMU8000 processor on the SB AWE series of cards. SoundFX emulates an FM chip and provides various configuration options for the FM sample rate. A free trial version is available from the site. The full version costs £25 or $40. http://www.softsystem.co.uk/page3.htm

Virtual PC, like VMWare, allows you to run multiple operating systems under an emulated PC. It includes SB emulation, complete with an FM emulator. When used with DOS, it allows a few games that wouldn't run under Windows XP to work, although it is very expensive if you just use it for DOS gaming. http://www.connectix.com/

CLI2NOP is supplied as part of SoundFX NT and is included in the free trial ZIP file. It allows some games to run that otherwise wouldn't due to their use of interrupts. A full explanation is included in the cli1nop.bat file included with SoundFX NT.

 

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