Atari POKEY
|
|
Atari POKEY (C012294) pin-outThe 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.
| Contents |
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
Pokey music
The design of the POKEY made it possible for games to have polyphonic music and sound effects of up to four channels. One of the sound-engines developed for the Atari 8-bit family was called the AMP engine (Advanced Music Processor). This was used by the musician Gary Gilbertson.
Now it is possible to emulate the POKEY's sound capabilities in software. This can be done with the SAP player[1] (http://asma.atari.org/).
See also
External links
- ASMA — Atari SAP Music Archive (http://asma.atari.org/) A collection of POKEY chip-music (SAP) players and SAP music from various Atari 8-bit games.