Sound Blaster Settings in DOSBox: IRQ 7, DMA 1, Address 220 — In Plain Words

The manual’s exact words

The manual’s answer to “There is no sound” says:

“Be sure that the sound is correctly configured in the game. This might be done during the installation or with a setup/setsound utility that accompanies the game. First see if an autodetection option is provided. If there is none try selecting Soundblaster or Soundblaster 16 with the default settings being ‘address=220 irq=7 dma=1’ (sometimes highdma=5).”

The manual adds, in that same answer: “The parameters of the emulated sound cards can be changed in the DOSBox configuration file.”

The configuration file is DOSBox’s settings file.

What each word means, in plain words

These are glosses — plain-words framing to help you read the manual’s line. The numbers themselves are the manual’s, quoted above.

• Address 220 — the address is the place the game looks for the sound card. If the game looks in a different place than DOSBox uses, it will not find the card.
• IRQ 7 — IRQ is the number the sound card uses to get the computer’s attention. The game and DOSBox must be set to the same one.
• DMA 1 — DMA is another matching setting. The game and DOSBox must be set to the same one.
• highdma 5 — the manual lists this only with the word “sometimes”: “(sometimes highdma=5).” It is another DMA setting in the manual’s line, and it also has to match.

So the whole job is matching: pick Soundblaster or Soundblaster 16 in the game’s setup, and use the same address, IRQ, and DMA numbers the manual gives.

What DOSBox provides by default

The manual’s answer to “What sound hardware does DOSBox presently emulate?” lists “SoundBlaster 16 / SoundBlaster Pro I & II / SoundBlaster I & II” and says:

“By default DOSBox provides Soundblaster 16 level 16-bit stereo sound. You can select a different SoundBlaster version in the configuration of DOSBox.”

In plain words: DOSBox starts out pretending to be a SoundBlaster 16. That is why the manual’s no-sound answer tells you to select Soundblaster or Soundblaster 16 in the game.

The [sblaster] section in the configuration file

Sound Blaster settings live in the part of the configuration file headed [sblaster].

The wiki’s dosbox.conf page is very short on this section. In full, its [sblaster] section says “Sound Blaster related settings” and points to a Sound page for more. The wiki page does not list setting names or values for this section on that page.

So this page does not print a list of [sblaster] values from the wiki, because the wiki page does not give one. The setting name the manual itself uses in the configuration file is sbtype — see the next sections for the exact values the manual prints for it.

sbtype — picking a different Sound Blaster, or turning it off

sbtype is the name the manual uses in the DOSBox configuration file. In plain words, it picks which Sound Blaster DOSBox provides. The manual prints these values for it:

• sbtype=sbpro1 — the manual’s no-sound answer says: “In certain cases it might be useful to use a different emulated sound device like a soundblaster pro (sbtype=sbpro1 in the DOSBox configuration file) or the gravis ultrasound (gus=true).”
• sbtype=none — this turns Sound Blaster emulation off. See the next section for the two places the manual says to use it.
• sbtype=sb16 — the manual mentions this as the setting to go back to after using sbtype=none for Tandy sound: “Don’t forget to set the sbtype back to sb16 if you don’t use tandy sound.”

When the manual says to use sbtype=none

The manual’s list of emulated sound hardware says, under Tandy DAC: “Some games may require turning off sound blaster emulation (sbtype=none) for better tandy DAC sound support.”

The manual’s Troubleshooting section gives the same setting a different job. For a game that closes DOSBox, crashes, or hangs, it says to see if the game works with a default DOSBox installation and to try it with sound disabled, and adds: “additionally you can set sbtype=none and gus=false in the DOSBox configuration file”.

In plain words: sbtype=none is a test and a workaround in the manual, not the normal setting. The normal setting the manual points back to is sbtype=sb16.

If a game has no sound — the manual’s steps, in order

• Be sure the sound is correctly configured in the game. The manual says this “might be done during the installation or with a setup/setsound utility that accompanies the game.”
• First see if an autodetection option is provided.
• If there is none, try selecting Soundblaster or Soundblaster 16 with the default settings address=220 irq=7 dma=1, sometimes highdma=5.
• If you still don’t get any sound, the manual says: “set the core to normal in DOSBox configuration and use some lower fixed cycles value (like cycles=2000).”
• The manual also says: “assure that your host operating sound does provide sound.” In plain words, check that sound works on your real computer outside DOSBox.
• And, as quoted above, the manual says in certain cases it might be useful to use a different emulated sound device, like a SoundBlaster Pro with sbtype=sbpro1, or the Gravis Ultrasound with gus=true.

Not the Sound Blaster numbers — the music device in the same answer

The manual’s no-sound answer also says: “You might also want to select Sound Canvas/SCC/MPU-401/General MIDI/Wave Blaster at ‘address=330 IRQ=2’ as music device.”

That line is about picking a music device. It is not the Sound Blaster setting. Do not put address 330 or IRQ 2 into the Sound Blaster setup — the Sound Blaster defaults in the manual are address 220, IRQ 7, and DMA 1.

If the sound stutters or sounds stretched or weird

That is a different problem from no sound, and the manual answers it separately:

“You may be using too much CPU power to keep DOSBox running at the current speed. You can lower the cycles, skip frames, reduce the sampling rate of the respective sound device, increase the prebuffer.”

The manual points to the configuration file section for those settings.