Digital sound revolution

The digital sound revolution (or digital audio revolution) refers to the widespread adoption of digital audio technology in the computer industry beginning in the 1980s.

Some of the first computer music was created in 1961 by LaFarr Stuart, who wrote software to modulate the duration of and between pulses (pulse-width modulation or "PWM", via a process now often referred to as "bit-banging") on a bus line that had been connected to an amplified speaker originally installed to monitor the functioning of Iowa State University's CYCLONE computer, a derivative of the Illiac. The entire computer was used to create simple, recognizable tunes using digital audio.

The speakers in the IBM PC (released in 1981) and its successors may be used to create sounds and music using a similar mechanism.

The first specialized audio circuits in computers included simple analog oscillators that could be set to desired frequencies, generally approximating tones along the musical scale. An example of this is Atari POKEY custom ASIC used in the Atari 800.

The next development was to produce a base frequency, and then modulating it with analog filters to create desired effects; this process of audio waveform synthesis using frequency modulation is usually referred to as FM synthesis. This technology was introduced in the early 1980s by Yamaha, which began manufacturing FM synth boards for Japanese computers such as the NEC PC-8801 and PC-9801 in the early 1980s. This allowed personal computer game audio to have greater complexity than the simplistic beeps from internal speakers. These FM synth boards produced a "warm and pleasant sound" that musicians such as Yuzo Koshiro and Takeshi Abo utilized to produce video game music that is still highly regarded within the chiptune community.

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