Sound Cards
Introduction
For the first 5-6 years of the IBM PC and its compatibles, their audio output came from nothing more than a simple loudspeaker with a tone generator. For business, this was acceptable - even preferable, since a PC in an office environment really shouldn't be a distraction to others! Only when games started to become more mainstream did the PC get acceptable audio.
With the introduction of the Ad Lib sound card in 1987, the world of PCs would begin its period of growth in home entertainment. As with most successful ventures, it wasn't long before a flurry of competitors entered the stage for a piece of the action.
As well as Ad Lib, a number of other "formats" were supported by games to varying degrees. Some of these are:
- IBM Music Feature Card
- Tandy 1000
- Covox Speech Thing / Disney Sound Source (DSS)
- Windows Sound System
- Gravis Ultrasound
- MediaVision Pro Audio Spectrum
- Roland MT-32 / LAPC-I
- General MIDI
It would be easy to state that Creative Labs cornered the market in the DOS gaming era, but that would be unfair to focus solely on the utter maelstrom of sound cards produced by them, as other manufacturers over time often produced some arguably better sounding solutions.
There is a lot more to a sound card than just the main chips which affect audio quality, but when comparing sound cards there are three primary chips responsible for setting the baseline for a card's capabilities. They are:
- the FM synthesizer chip
- the audio codec chip
- the DAC (Digital-to-Analog Converter) chip
For a more detailed look at these chips, please read the FM Synthesizers, Codecs and DACs page. Of course a sound card may have high-quality chips but supporting circuitry may be of poor quality or badly designed, resulting in a "noisy" card.
Catching the Wave
If you're relatively new to understanding PC audio hardware from 1985 to 1995, this may help clear up some misconceptions. Broadly speaking, there are five categories of audio hardware for the PC. These are:
1) An FM synthesis sound card with no digital sample playback capability, e.g. Ad Lib.
2) A sound card that supports both FM synthesis and basic digital sample playback, e.g. Sound Blaster.
3)
A sound card that either has Wavetable samples onboard *or* has a header to allow an optional daughterboard to be connected. Many 16-bit ISA sound cards have one of these headers.
4) A wavetable daughterboard - not a sound card in its own right, these are modules that supplement a sound card, providing it with wavetable samples.
5) A MIDI synthesizer (either on a card or an external device) - if on an external device these need to be connected to an interface or a sound card's MIDI/Game port to receive details of what to decode and playback.
Sound Cards Listed
PC audio is quite a large topic, so here are some links to my audio hardware manufacturer pages: