Atari POKEY
Atari POKEY (C012294) pin-out
The
Atari POKEY is a digital
I/O chip found in the
Atari 8-bit family of home computers and many
arcade games in the
1980s. Its name comes from
POtentiometer and
KEYboard, as it was commonly used to sample (
ADC) potentiometers (such a game
paddles) and scan matrices of switches (such as a computer
keyboard). POKEY is also well known for its sound effect and music generation capabilities, producing a distinctive
square wave sound popular among
chip tune aficionados. The
LSI chip has 40 pins and is identified as
C012294.
The USPTO granted U.S. Patent 4,314,236 to Atari on February 2, 1982 for an "Apparatus for producing a plurality of audio sound effects". This referred to POKEY's sound generation abilities. The inventors listed were Steven T. Mayer and Ronald E. Milner.
No longer manufactured, POKEY is emulated in software by classic arcade emulators (e.g. MAME) and Atari 8-bit emulators.
Features
- audio
- 4 semi-independent audio channels
- channels may be configured as one of:
- four 8-bit channels
- two 16-bit channels
- one 16-bit channel and two 8-bit channels
- per-channel volume, frequency, and waveform (square wave with variable duty cycle or polynomial noise)
- high-pass filter
- keyboard scan (up to 64 keys)
- pot ports (8 independent ports, each with 8-bit resolution)
- timers (audio channels 1, 2, and 4 can be configured to cause timer interrupts when they cross zero)
- random number generator (8 or 9 bits of a 17-bit polynomial counter can be read)
- serial I/O port
- IRQ interrupts