SN76489

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SN76489
SN76489AN - Bare.jpg
Developer: Texas Instruments
Released: 198?-??-??
Type: Chip
Channels:

1.) Pulse Wave
2.) Pulse Wave
3.) Pulse Wave
4.) Noise

The SN76489 is a family of PSGs designed by Texas Instruments and released in the early 1980s. Each version of the chip features 3 pulse wave channels and 1 noise channel. The noise channel can be put into either periodic noise or white noise mode. This was a significant improvement on their earlier chip, the SN76477 and gave rise to copycats emulating TI's 3 Voice Chipset. These improvements made the SN76489 series widely popular throughout the 1980s, but couldn't overtake the AY-3-8910 which dominated the audio chip market at the time.

Versions

Minor additions were made to each model in the family, but each is backward compatible to the previous models.

SN76489

SN76489AN - Bare.jpg

Original is SN76489, narrow version is SN76489N, revised is SN76489A, revised narrow is SN76489AN.

SN76494

SN76494N - On a TI 99-8.jpg

Original is SN76494, narrow version is SN76494N, revised is SN76494A, revised narrow is SN76494AN. Unlike the SN76889, which doesn't use pin 9, the SN76494 utilizes the pin for audio input.

SN76496

SN76496 - On a PCjr.jpg

Original is SN76496, narrow version is SN76496N, revised is SN76496A, revised narrow is SN76496AN. Like the SN76494, pin 9 is used for audio input.

The chip was cloned by NCR who produced the very similar NCR 8496. However, the clone never took off and appears to have only been used in the Tandy 1000 line of computers. The chip was also used in Sega's Game Gear, adding a stereo effect.

Devices

Over the years, a number of computers, video game consoles, and peripheral devices used the SN76496. This is a chronological breakdown of those devices.

Release Device Chip
1981-12-01 BBC Micro  ?
1981-??-?? CreatiVision  ?
1982-08-?? ColecoVision SN76489AN x1
1982-11-?? Sord M5  ?
1983-07-15 SG-1000 SN76489AN
1983-10-?? Coleco Adam  ?
1984-03-?? PCjr 3 Voice SN76496N x1
1984-11-?? Tandy 3 Voice  ?
1986-06-?? Master System  ?
1986-??-?? BBC Master  ?
1988-10-29 Mega Drive/Genesis  ?
198?-??-?? MC1 SN76489N x3
198?-??-?? MZ-800  ?
1993-06-26 Pico  ?
1995-10-?? Nomad  ?
1998-10-28 Neo Geo Pocket  ?
1999-03-16 Neo Geo Pocket Color  ?
Unreleased (c. 1983) TI 99/8 SN76494N x1

Games

The SN76489 series didn't see the popularity of it's competitor the AY-3-8910, but it did see a lot of use in the early 1980s.

1980

According to the MAME arcade database, the first time a SN76489 chip appeared on an arcade game was 1980 on Space Force. However, this may be a mistake since it sites the use of three SN76496 chips, but it is unlikely that these particular chips were manufactured until around 1983.

List of 1980 Games
Release Game Chip Sample
1980-??-?? Space Force (ARC) 3x SN76496 No Music

1981

Despite the release of the new SN76489 chip, the older SN76477 saw more use in 1981. However, both chips fell far from the ubiquity of the AY-3-8910.

List of 1981 Games
Release Game Chip Sample
1981-??-?? Cosmic Avenger (ARC) 2x SN76489
1981-??-?? Lady Bug (ARC) 2x SN76489N
1981-??-?? Space Bugger (ARC) 2x SN76489

1982

There was an increase in the usage of the SN76489 in 1982 to close to 10 different cabinets, and the chip overtook the older SN76477 model. However, Texas Instruments wasn't even making a dent in the AY-3-8910 market which had about 10 times the popularity.

List of 1982 Games
Release Game Chip Sample
1982-??-?? Dorodon (ARC) 2x SN76489
1982-??-?? Lasso (ARC) 2x SN76489
1982-??-?? Slither (ARC) 2x SN76489
1982-??-?? Snap Jack (ARC) 2x SN76489
1982-??-?? Space Raider (ARC) 5x SN76489
1982-??-?? Super Locomotive (ARC) 2x SN76496

Downloads

Document Download
SN76489AN Manual Download - (info)
SN76494 / SN76496 Manual Download - (info)

Picture Gallery

Emulation Status

Due to the chip's popularity, it has been emulated several times.

  • DOSBox emulates it for PCjr and Tandy support.
  • MAME has emulated it for the various arcade games that require it.
  • Any console or computer emulator in the list of devices above that has music must emulate some version of the SN76489.

Links