Sound hardware was probably one of the more complex and irritating elements of DOS gaming in the early 1990’s. So many choices, incompatibilities and even different advantages and disadvantages for sound effects/speech or music. So what do you choose today, especially when an emulator like DOSBox gives you so many audio choices?
Well this entry will describe the major sound cards that impacted the DOS era of PC gaming, a brief history and their compatibility with DOSBox. I will also create a chart that will list in my opinion, the best music and sound effect emulation options for your gaming titles.
Definitions:
PCM – Pulse Code Modulation, is a digital representation of an analogue sample, also used by audio CDs and occasionally on DVDs
DAC – Digital to Analogue Converter, used for playing back digital sound and music through standard speakers and headphones.
ADC – Analogue to Digital Converter, used for recording samples from a standard microphone and storing it on a digital format on the computer.
DSP – Digital Signal Processing or Processor essentially is the same as DAC/ADC combined meaning it allows for both digital to analogue playback and analogue to digital recording.
channel – A single music instrument or sound sample
FM synthesis – frequency modulation synthesis, generates and distorts an audio tone to fake an instrument, often used on synthesises from 1980’s and earlier and has a very electronic, artificial sound.
Wavetable synthesis – In PC audio it refers to pre-recorded sounds and samples or instruments that are then manipulated for tone and pitch.
PC speaker
1 tone generator, mono.
Introduced as the only form of audio output on the original IBM PC back in August 1981. The PC speaker had the ability to only play one waveform tone at one time, making it useless for music and gaming. The notoriety of the speaker’s quality would later earn it the title of the PC squeaker or PC beeper.
Given what was available on other, cheaper computers at the time one can only assume this offering by IBM was a form of cost cutting. Though, the PC’s target market were business applications so it is understandable why IBM originally choose to ignore audio in its original PC specification.
Unfortunately this limited audio ability would later come to haunt the PC especially with gaming. It would take well over a decade for entrench audio replacements to become standard.
Developers did find hacks around the limitations of the PC speaker with various games for the era managing to reproduce multiple toned music, digital sound-fx and even speech. At best these hack reproduced a 6bit, single PCM DAC like channel. Unfortunately they had many problems that limited it’s wide spread usage. Firstly they were often CPU speed sensitive, whereby a processor that would be too fast or slow would distort and warp the audio output. There was no volume control, just an off/on BIOS option. The output volume was often too quiet making it hard to hear, and this was compounded by the fact most PCs had the speaker hidden deep inside the PC’s steal casing.
A bargain basement Commodore VIC-20 from the same era came with a RRP of $299.95US. In comparison the IBM PC started with a RRP of $1,565 for a base model. Yet the VIC-20 has significantly better audio capabilities then the IBM.
“The VIC chip had three rectangular-wave sound generators. Each had a range of three octaves, and the generators were located on the scale about an octave apart, giving a total range of about five octaves. In addition, there was a white noise generator. There was only one volume control, and the output was in mono.” – Wiki
DOSBox emulates all functionality of the PC Speaker including the PCM like DAC hacks; though usually you will need to manually adjust the DOSBox speed (cycles) settings to get it working correctly.Dunzhin: Warrior of Ras Volume I by Computer Applications Unlimited from 1982 is an early example of DAC playback through the PC speaker.
Tandy 1000 / Tandy DAC
3 pulse-width modulation channels plus one white channel, mono
8-bit DAC up to 22050 KHz, mono
The original Tandy 1000 series of computers that first came out in 1984 upgraded the internal PC speaker to three channels plus white noise. Later models also allowed for external volume control and support for headphones. When implemented in software the Tandy 1000 audio is a big improvement over the default PC speaker.
In 1989 Tandy released the 1000 SL series of computers that updated their 3 channel audio chip to incorporate an onboard 8bit, mono DAC/ADC for digital sampling and playback. This was supported by a number of games, including a few Sierra titles (like Space Quest 3). They experimented with it for a brief period before the Creative Sound Blaster went retail and took their attention away.
DOSBox emulates both Tandy audio (3 channel) and Tandy DAC.
I recommend setting the DOSBox.conf tandy=true rather than tandy=auto to force older games to auto-detect the Tandy 3 channel audio. You might also have to set the DOSBox machine=tandy. For Tandy DAC, DOSBox also requires that sbtype= is set to any allowed value other then none.
- BattleTech 2 – Tandy 1000 speech and music
- SimCity sound effects compared, original PC, Tandy DAC
- Space Quest 3 – Tandy 1000 music
- Space Quest 3 – Tandy 1000 SL/TL music, effects and speech
- Ultima 6 – Tandy 1000 music
Covox Speech Thing / Disney Sound Source
8-bit DAC, mono
The Covox Speech Thing was a simple 8bit DAC/ADC adapter that plugged into a PC’s parallel printer port. Originally released in 1986, it later was revised and marketed under various brands and names, including Disney who in the early 1990’s used it for use in their education software.
Note there are a few games that support the Covox Voice Master / Sound Master; this was an internal sound card rather than a printer port adaptor. DOSBox does not support these internal Covox based cards.
DOSBox emulates the Covox printer devices including The Disney Sound Source, which offers better audio quality.
AdLib / OPL2 / YM3812
9 channel FM synthesis, mono
Introduced in 1987 the AdLib Music Synthesizer Card was the first add-on music card to gain wide spread support within the PC industry. While it wasn’t the first, nor was it the most popular, it became the de-facto standard for software and game manufactures in the early 1990’s when music and sound card support first became common.
To implement support early games often required an AdLib driver known as a DOS TSR (Terminate and Stay Resident) to be loaded into memory. Though this requirement was later dropped as many games included and loaded their own audio drivers. The card used a Yamaha YM3812 9 channel FM synthesis chip which is also known as the OPL-2.
Moby Games states that in 1987 there were only 3 games with AdLib support. By 1988 there were 9 games with support, 53 out of 342 in 1989 and 138 out of 406 in 1990, 150 out of 381 in 1991.
DOSBox emulates AdLib audio. AdLib emulation is set using oplmode=. auto tells DOSBox to control emulation. opl2 emulates the original AdLib, that is also used by the original Sound Blaster. dualopl2 emulates two OPL-2 chips, as used by the first generation of Sound Blaster Pro cards. opl3 emulates the AdLib Gold series of cards and was also used by the Sound Blaster 16.
Roland MT32 / MPU401 / LAPC-1
32 channel wave synthesis, stereo
The Roland MT-32 Sound Module from the Japanese company Roland was released in 1987. It was a programmable synthesiser that supported up to 32 notes played at once using a 16-bit DAC at a sample rate of 32000 HZ.
Quality was significantly better than the alternative AdLib, and the Roland retail prices represented this.
MobyGames game support: 1988 there were 6 DOS games with support; 24 in 1989, 68 in 1990 and 87 in 1991.
DOSBox provides interface support to MPU401 hardware attached to your computer. DOSBox does not offer MPU401 emulation, rather it uses your soundcard’s own General MIDI implementation. Of which the quality and accuracy will vary depending on your audio card, drivers and operating system. The default DOSBox mpu401 settings should work for most people.
Creative Music System / Game Blaster
Twin 6 channel FM synthesis, stereo
Creative Music System released in 1987 was the first add-on soundcard by the Singaporean based company that would later become Creative Labs. The card used two Philips SAA 1099 chips that each supported 6 channels of wave a noise in stereo. Price at a similar level to the AdLib, the CMS audio was of poorer quality so it never gained wide industry support.
“sounding not unlike twelve simultaneous PC speakers” – Wiki quote
MobyGames game support: in 1987 there was one game with CMS support, 6 in 1988 and 17 in 1989. By 1990 there were 40 but this dropped down to 17 titles in 1991 after the Sound Blaster was popularised.
Sound Blaster 1 / 2
9 channel FM synthesis, single 8 bit DSP, mono
Sound Blaster 1.0 first appeared in 1989 and was the successor to the not so popular Creative Music System that was by then known as the Game Blaster. The Sound Blaster 1.0 was a kind of hybrid card in that it offered backwards support for its earlier Game Blaster series. It also included the Yamaha YM3813 chip that was used in the more popular AdLib card. In addition Creative also included a digital signal processor allowing the playback of sampled sound at 23 KHz and recording at 12 KHz. Priced in retail at the same level as the AdLib and with the additional value add-ons such as a built in game port. The Sound Blaster out valued and out featured its rival, eventually forced the AdLib company to file for bankruptcy.
MobyGames game support: 4 in 1988, 9 in 1989, 71 in 1990, 115 in 1991.
Sound Blaster 1.5 released in 1990 removed the included CMS support, probably as a cost cutting measure.
Sound Blaster 2.0 was released in 1991 and basically offered improvements to the digital signal processor chip. Upgrading the playback to 44KHz 8 bits and allowed for auto-DMA which removed an undesirable clicking sound that was audible in earlier cards.
Sound Blaster Pro
Twin 9 channel FM synthesis, twin 8 bit DSP, stereo
Sound Blaster Pro 1.0 for all intent and purposes was the successor to the Sound Blaster series of cards with the introduction stereo. Like the earlier CMS line of cards it used two YM3812 chips to emulate stereo. Though games had to be specially programmed for this to work otherwise the games would only detect a single, mono chip. The DSP chip was upgraded to allow for 44KHz 8 bit samples in mono or 22KHz samples in stereo.
Sound Blaster Pro 2.0 removed the twin YM3812 chips and replaced them with a single Yamaha YMF262 otherwise known as the OPL-3. It allowed for 20 FM synthesis channels in stereo.
DOSBox emulates the Sound Blaster 1, 2 and Pro. sbtype= allows you to manually force Sound Blaster emulation. sb1 emulates the original mono Sound Blaster. sb2 emulates revision 2 of the same card. sbpro1 emulates Sound Blaster Pro. sbpro2 emulates revision 2 of the card. sb16 emulates the Sound Blaster 16.
Pro AudioSpectrum (PAS)
Twin 9 channel FM synthesis, 8bit DSP, stereo
Created by newly formed Californian based Media Vision. The first Pro AudioSpectrum released in 1991 was an 8 bit stereo card that used two YM3812 chips for FM music and had its own DSP chip. I am pretty sure the DSP chip was stereo but was not Sound Blaster compatible, limiting its appeal. It did however include a SCSI CDROM interface allowing the connection of a then new to market CDROM drive. There were significant savings for buyers who purchased a PAS over a SB Pro with a separate SCSI card.
There is no AudioSpectum emulation in DOSBox.
Pro AudioSpectrum Plus / 16 (PAS)
18 channel FM synthesis, 16bit 44KHz DSP, stereo
Released in 1992 the PAS 16 supported 16 bit 44KHz playback and 16 bit recording. Because of the built in SCSI CDROM interface, the card would often be bundled with expensive multi-media packages which included a CDROM drive. The 16 bit PAS was price at the same point as Creative’s 8 bit Sound Blaster Pro, making it a popular choice for non-gamers.
The PAS Plus and PAS 16 are essentially the same cards for audio playback. They are both backwardly compatible with AdLib, Sound Blaster 1.5 and the original PAS.
There is no AudioSpectum Plus/16 emulation in DOSBox.
Sound Blaster 16
18 channel FM synthesis, 16bit 44KHz DSP, stereo
Released in the middle of 1992, the 16 series was the next major upgrade to the Sound Blaster range of cards. It finally saw Creative catch up to competing cards by offering 16 bit, 44KHz playback. Music was upgraded to the now standard Yamaha OPL-3 chip. In retail it came with the usual Creative price mark-up but it did offer backwards compatibility with the earlier SB series.
DOSBox emulates SoundBlaster 16 audio.
Gravis Ultra Sound
14 wave-sampled channels at 16 bit 44KHz DSP or 32 channels at 19Khz, stereo
In 1992 Advanced Gravis a well known Canadian joystick company brought out the bright red and quite long Gravis Ultra Sound add-on card. Priced slightly higher than the Sound Blaster Pro, the Ultra Sound gave users lots of bang for their buck. Unfortunately this was at the expense of compatibility with the Sound Blaster series. Leaving most gamers with current titles having no or limited audio support.
The card itself was a wave-table soundcard with 256kbs of RAM built in. Unlike the Sound Blaster AWE-32 it did not come with any pre-saved samples, so everything had to be loaded through software drivers or by the game itself. As the card did not offer any hardware emulation for Sound Blaster DSP chip or even the now ancient AdLib OPL-2 chip, everything had to be emulated using uploaded samples. This required extra computer memory, CPU resources and often utilised hacks and patches to get many non-supported games to work. This meant that some owners of a GUS would also had a cheap Sound Blaster clone in their machine for complete gaming compatibility.
On the plus side, when games did offer support for the GUS, it offered far greater audio capability than anything else on the home consumer market. It allowed for 14 channels at 44KHz playback or 32 channels at 19.2KHz.
A number of games require the use of GUS drivers that can be downloaded from here. These cannot be distributed with DOSBox as their copyright is incompatible with the DOSBox GNU open source license. You will need to unzip the drivers to a directory which is usable within the DOSBox shell. Then change ultradir= to point to the directory. Other then this requirement, DOSBox offers complete GUS emulation.
Sound Blaster AWE32
30 channel wave synthesis, 16bit 44KHz DSP, stereo, EAX like effects
In early 1994 Creative released the Sound Blaster AWE-32 which for all intents and purposes was basically a Sound Blaster 16 with a built in synthesizer board and effects chip. This was useless though unless the game directly supported these features which was not common. The card came with a 1mbit sample ROM and included 512kbit of RAM for user samples. It used 30 sampled channels plus two channels for the FM OPL-3 synthesizer.
Using software drivers it could also attempt to emulate General MIDI and MT-32 audio. Though the drivers consumed valuable conventional memory and were not able to work with common 32-bit protect mode DOS programs.
A budget version of the card was released in 1995. Known as the Sound Blaster 32, it removed the included RAM as well as support for bass, treble and gain adjustments.
There is no DOSBox emulation for the AWE32 series.
General MIDI – GM/GS
24 channel wave synthesis
General MIDI is not a sound card rather it is a 1991 standard for synthesisers that were later adopted to PC audio composing cards and by game developers for use in their games. The standard requires the use of at least 24 simultaneous voices and uses 128 predefined sounds.
GS was an extension to General MIDI that was created by Roland the makers of the original MT-32. The first GS generation introduced extra predefined General MIDI sounds taking the total number up to 226.
Quality of General MIDI and GS is totally dependent on the pre-recorded samples or instruments used by the sound cards. Often cards that claimed ‘GM compatibility’ by using their in built ROM samples sounded inferior, sometimes even offensive when compared to an authentic Roland-built General MIDI PC card.
Most of the time support for General MIDI could be tied to a Sound Blaster. The Sound Blaster would provide the digital sound effects and speech while the General MIDI device would provide the music.
General MIDI mapping is provided in DOSBox, but the sample quality is dependent on your computer’s soundcard and operating system. Most modern Creative cards using the default Windows XP or Vista MIDI device sound reasonably authentic.
DOSBox Supported Devices .. in which order are the best to use?
This chart is a matter of personal opinion and is based on running DOSBox under Windows XP/Vista host system with a Sound Blaster Audigy 2 and a pair of amplified stereo speakers. Of course audio quality will also depend on the software or game operating under DOSBox.
| Music | Sound Effects and Speech | |
| Best | Gravis UltraSound – 1992 | Gravis UltraSound |
| General MIDI (depending on your host operating system and setup) – 1991 | Sound Blaster 16 | |
| Roland MT-32 (real device) – 1987 | Sound Blaster Pro | |
| Sound Blaster 16 / Sound Blaster Pro 2/ OPL-3 – 1992 | Sound Blaster | |
| Roland MT-32 (when mapped to a GM driver) – 2005 | Disney Sound Source – 1990 / Covox Speech Thing / Tandy DAC – 1986 | |
| Sound Blaster Pro -1991 | Tandy 1000 / Creative Sound Master / Game Blaster / PC speaker | |
| Sound Blaster / AdLib / OPL-2 – 1987 | AdLib / MT-32 | |
| Creative Sound Master / Game Blaster – 1988 | ||
| Tandy 1000 – 1983 | ||
| Worst | PC Speaker – 1981 |
Great article! I actually found this only because I was looking for the GUS drivers for DOSBox
but it sure was an interesting read. Thumbs up!
Comment by Daniel — June 26, 2008 @ 5:51 am |
Wow… This is going to be invaluable in setting up games in DOSBox! I’m only early in the article still, but wanted to toss a comment at you both in thanks and to point out that the audio samples you linked to for each section are giving 404 (not found) errors.
Comment by Koselara — November 13, 2008 @ 6:22 pm |
good lord this takes me waaay back. And go figure, I still have this cute little Disney SoundSource box, is has a converter with MICKEY MOUSE ears too.
I wonder what I should do with it? Is there a museum for stuff like this?
It almost ended up in the garbage really. Now I wonder if it should be saved… (sigh).
Comment by shanna — January 3, 2009 @ 12:40 am |
There are computer museums world wide. Just type ‘computer museum’ in Google and go from there. Else you could always put it on Ebay, there are many private collectors for things like this. Just don’t go into the auction expecting a super high price.
Comment by Ben — January 3, 2009 @ 9:50 am |
The links to the audio samples have been fixed and are now working.
Comment by Ben — March 27, 2009 @ 5:39 pm |
Hello I’d Just like to point out something how do i enable sound blasters infamous “p330″ because ROTT and SHADOW WARRIOR won’t do 16bit sound without P330
Comment by Peter — June 20, 2009 @ 3:51 pm |
Are you sure you think your using the correct hack? Because the SET BLASTER = P330 sets the MIDI port, and that has nothing to do with 16bit sound.
http://www.rinkworks.com/apogee/s/6.4.2.shtml
Anyway if you do need to add the SET BLASTER path you can do it by editing the DOSBox config file. Scroll to the very bottom until you find the lines below and add your SET BLASTER setting, but make sure it matches the DOSBox Sound Blaster settings.
[autoexec]
# Lines in this section will be run at startup.
SET BLASTER=A220 I7 D1 T3 P330 H5
Comment by Ben — June 20, 2009 @ 9:06 pm |