Platform - Computer » Apple IIgs
The Apple IIgs' sound was provided by an Ensoniq ES5503 DOC wavetable sound chip, the same chip used in Ensoniq Mirage and Ensoniq ESQ-1 professional-grade synthesizers. The chip allowed for 32 separate channels of sound, though most software paired them into 16 stereo voices, as did most of the standard tools of the operating system (the MIDISynth Tool Set grouped four channels per voice, for a limit of seven-voice audio). The IIgs is often referred to as a "fifteen-voice system," though one stereo voice is reserved by the OS at all times for timing and system sounds. Software that doesn't use the OS, or uses custom-programmed tools (most games and demos do this), can access the chip directly and take advantage of all 32 voices.
A standard 1?8-inch headphone jack was provided on the back of the case, and standard stereo computer speakers could be attached there. However, it provided only mono sound through this jack, and a third-party adapter card was required to produce true two-channel stereo, despite the fact that the Ensoniq and virtually all native software produced stereo audio (stereo audio was essentially built into the machine, but had to be de-multiplexed by third-party cards). Applied Engineering's SonicBlaster was one of a few developed cards for this purpose.