Atari · 1979 · 1970s–1980s · 4 voices
POKEY was Atari's combined audio and I/O chip for the 8-bit home computers, providing four independent voices capable of both pure tone and polynomial counter noise in a chip that also handled keyboard scanning, serial communication, and potentiometer reading.
POKEY (POtentiometer and KEYboard) was designed by Doug Neubauer at Atari and first appeared in the Atari 400 and 800 home computers in 1979, simultaneously in the Asteroids and Missile Command arcade PCBs. The chip provided four independent channels, each generating audio from a counter that could be clocked at different rates and combined with a polynomial counter for various noise textures. By selecting different clock divisors and poly counter lengths, composers could produce pure tones, white noise, buzzy tones, and unusual timbres not achievable on the AY-3-8910 or SN76489. A key technique was channel pairing — combining two 8-bit counters into a single 16-bit counter, which lowered the minimum frequency and enabled bass tones the Atari's competitors could not produce. POKEY also handled keyboard scanning, joystick port reading, serial I/O, and the random number generator in the same package — an unusually versatile chip.