The SN76489 Programmable Sound Generator (PSG) is a TTL compatible four-channel sound chip from Texas Instruments. Its main application has been the generation of music and sound effects in game consoles, arcade games and home computers (such as the BBC Micro). A Motorola 68000-based computer with various TTL chips. ... A sound chip is an integrated circuit (i. ... Texas Instruments (NYSE: TXN), better known in the electronics industry (and popularly) as TI, is a company based in Dallas, Texas, renowned for developing and commercializing semiconductor and computer technology. ... Sound effects or audio effects are artificially created or enhanced sounds, or sound processes used to emphasize artistic or other content of movies, video games, music, or other media. ... The Nintendo GameCube is an example of a popular video game console. ... Centipede by Atari is a typical example of a 1980s era arcade game. ... The home computer is a consumer-friendly word for the second generation of microcomputers (the technical term that was previously used), entering the market in 1977 and becoming common during the 1980s. ... The BBC Micro, affectionately known as the Beeb, was an early home computer. ...

Features of the SN76489 are:

• Three square wave, programmable tone generators
• One programmable white noise generator
• Programmable attenuation
• Mono audio output

The frequency of the square waves produced at each channel is derived by two factors: the speed of the external clock and a value provided in a control register for that channel (called N). Each channel's frequency is arrived at by dividing the clock by 32 and then dividing the result by N. A square wave is a kind of basic waveform. ... For other uses of the term white noise, see white noise (disambiguation). ... Attenuation is the decrease of the amount, force, magnitude, or value of something. ... Sine waves of various frequencies; the lower waves have higher frequencies than those above. ...

An SN76489 clone is included 'on-chip' in SEGA's Video Display Processors (VDP) for their Master System, Game Gear, and Mega Drive (Sega Genesis in North America), game consoles. The basic functions are the same, but the randomness for the noise channel is generated differently. Sega Corporation ) is an international video game software and hardware developing company, and a former home computer and console manufacturer. ... Sega Master System The Sega Master System (SMS for short) (Japanese: マスターシステム), was an 8-bit cartridge-based gaming console manufactured by Sega. ... The Sega Game Gear was Segas first portable gaming system. ... Sega MegaDrive 2 European version with joypad, game cart + box Sega Mega Drive (Japanese: メガドライブ Mega Doraibu) was a 16-bit video game console released by Sega. ... The Mega Drive/Genesis was a 16-bit video game console released by Sega in Japan (1988), Europe (1990) and most of the rest of the world as the Mega Drive. ... World map showing North America A satellite composite image of North America. ...

External links

• Data Sheet (Original PDF)
• SN76489 Data Sheet
• SN76489 Sound Chip Details
• SN76489 Notes