Programmable sound generator

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A programmable sound generator (PSG) is a sound chip that generates (or synthesizes) audio signals built from one or more basic waveforms, and often some kind of noise. PSGs use a relatively simple method of creating sound compared to other methods such as frequency modulation synthesis or pulse-code modulation. [1]


Technical details

PSGs are controlled by writing data to dedicated registers on the chip via an external CPU; hence the name programmable sound generator. One or more basic waveforms are generated (typically a square, triangle or saw-tooth wave) and often a noise signal. The waveforms' frequency and volume (and noise's tone and volume) are typically shaped using an envelope and or mixed before being sent to the audio output stage. [1]

Many PSGs feature three tone channels and one noise channel including the AY-3-8910, SN76489 and MOS Technology 6581.


In the late 1970s, more electronic consumer devices began to be designed with audio features. PSG were partly developed as a way of incorporating relatively complex sounds at a low cost. [1] [2] PSGs were in many arcade games, game consoles, and home computers of the 1980s and 90s.

In 1978, General Instrument released the AY-3-8910, the design of which was later licensed by Yamaha Corporation for their YM2149. These chips were used as the standard for the MSX computer standards 1 and 2, respectively. The features of this chip were also incorporated into other Yamaha sound chips including the YM2203 and YM2608 chips, these were also capable of FM synthesis. In the same year Atari design the POKEY chip for its home computers and game systems, it incorporate a PSG. [3]

In 1981, Texas Instruments SN76489 was produced for the TI-99/4 computer. This was also used in the Tandy 1000 and IBM PCjr.

In 1982, MOS Technology 6581 was produced for the Commodore 64. [4] The main chip in the Nintendo Entertainment System, the Ricoh 2A03, included a PSG. [3]

List of PSGs

Further reading

See also

Related Research Articles

MOS Technology 6581 sound chip

The MOS Technology 6581/8580 SID is the built-in programmable sound generator chip of Commodore's CBM-II, Commodore 64, Commodore 128 and Commodore MAX Machine home computers. It was one of the first sound chips of its kind to be included in a home computer prior to the digital sound revolution.

Yamaha YM2612 FM synthesis sound chip by Yamaha

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Texas Instruments SN76489 programmable sound generator chip

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Yamaha YM3812

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Roland SH-101 monophonic analog synthesizer

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Philips SAA1099

The Philips SAA1099 sound generator was a 6-voice sound chip used by some 1980s devices, notably:

General Instrument AY-3-8910 General Instrument AY-3-8910

The AY-3-8910 is a 3-voice programmable sound generator (PSG) designed by General Instrument in 1978, initially for use with their 16-bit CP1610 or one of the PIC1650 series of 8-bit microcomputers. The AY-3-8910 and its variants were used in many arcade games—Konami's Gyruss contains five—and pinball machines as well as being the sound chip in the Intellivision and Vectrex video game consoles, and the Amstrad CPC, Oric-1, Colour Genie, Elektor TV Games Computer, MSX, and later ZX Spectrum home computers. It was also used in the Mockingboard and Cricket sound cards for the Apple II and the Speech/Sound Cartridge for the TRS-80 Color Computer.

ARP Omni polyphonic analog synthesizer

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Synthesizer Electronic musical instrument

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Oberheim Xpander analog synthesizer

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Texas Instruments SN76477 Sound generating integrated circuit

SN76477 "complex sound generator" is a sound chip produced by Texas Instruments (TI). The chip came to market in 1978, and TI ceased production of the part. A 100% compatible version, identified as ICS76477, has been listed as 'in stock' by at least one US-based component stockist. The chip is typically used as a sound effects generator in arcade games and toys and for hobby projects. The use of the SN76477 in a musical context is limited by the fact that it was difficult to electronically control the pitch of the produced sound.

Yamaha YM2203

The YM2203, a.k.a. OPN, is a three-channel sound chip developed by Yamaha. It was the progenitor of Yamaha's OPN family of FM synthesis chips used in many videogame and computer systems throughout the 1980s and early 1990s. The YM2203 itself was used in a variety of NEC computers, along with various arcade game machines.

Yamaha YM2608

YM2608, a.k.a. OPNA, is a sixteen-channel sound chip developed by Yamaha. It's a member of Yamaha's OPN family of FM synthesis chips, and the successor to the YM2203. It was notably used in NEC's PC-8801/PC-9801 series computers.

Yamaha YM2164

The Yamaha YM2164 a.k.a.OPP, is an FM synthesis sound chip developed by Yamaha, an enhanced version of their YM2151 a.k.a. OPM. The OPP was used in various MIDI-based synthesizers by Yamaha - DX21, DX27, DX100, SFG-05, FB-01 - plus several licensed products: the IBM Music Feature Card and Korg's DS-8 and Korg 707.

Casio CZ synthesizers family of synthesizers

The CZ series is a family of low-cost phase distortion synthesizers produced by Casio in the mid-1980s. Eight models of CZ synthesizers were released: the CZ-101, CZ-230S, CZ-1000, CZ-2000S, CZ-2600S, CZ-3000, CZ-5000, and the CZ-1. Additionally, the home-keyboard model CT-6500 used 48 phase distortion presets from the CZ line. The CZ synthesizers' price at the time of their introduction made programmable synthesizers affordable enough to be purchased by garage bands. Yamaha soon introduced their own low-cost digital synthesizers, including the DX-21 (1985) and Yamaha DX100, in light of the CZ series' success.

Yamaha DX21

The Yamaha DX21 is a digital bi-timbral programmable algorithm synthesizer with a four operator synth voice generator which was released in 1985. It uses sine wave-based Frequency Modulation (FM) synthesis. It has two FM tone generators and a 32-voice Random Access Memory (RAM), 32 user voices and 128 Read Only Memory (ROM) factory preset sounds. As a programmable synth, it enables users to create their own unique synthesized tones and sound effects by using the algorithms and oscillators. The instrument weighs 8 kg (17.6 lbs). On its release, it sold for $795.


  1. 1 2 3 Burstein, S. (1979-02-01). "A multichannel programmable sound generator IC". 1979 IEEE International Solid-State Circuits Conference. Digest of Technical Papers. XXII: 218–219. doi:10.1109/ISSCC.1979.1155925.
  2. Torelli, G.; Caironi, G. (1983-08-01). "New Polyphonic Sound Generator Chip with Integrated Microprocessor-Programmable ADSR Envelope Shaper". IEEE Transactions on Consumer Electronics. CE-29 (3): 203–212. doi:10.1109/TCE.1983.356303. ISSN   1558-4127.
  3. 1 2 "Sound generators of the 1980s home computers". Retrieved 2019-12-02.
  4. "Full Page Reload". IEEE Spectrum: Technology, Engineering, and Science News. Retrieved 2019-12-02.