The Master System was a video game console produced by Sega beginning in 1985. For audio, the SMS used a clone of the Texas Instruments SN76489 chip. These clones were also present in the Sega Genesis and Game Gear systems, the latter adding stereo functionality.
The SN76489 chip has 1 white noise and 3 square wave tone generators. Each channel has 16 levels of volume. The third square wave channel can also be used to control periodic noise in the white noise channel.
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