Early Digital Audio Hardware

This chapter traces the development of interactive audio, from the 'hooter' on very early computers through to 1-bit audio and simple sound-chips on home micros. We hear how the basic issues of timing, pitch control, polyphony, acoustic envelopes and representations of volume have been addressed from first principles then adapted psychoacoustically.

Key people: Ada Lovelace, Alan Turing, Pete Sampson, Nolan Bushnell, Robert Yannes, Rob Hubbard, Matt Smith.

The oscillogram detail from the cover of the book was produced by a Sinclair ZX Spectrum's one-bit BEEP command

The oscillogram above shows output from a 1982 Sinclair ZX Spectrum's BEEP 8,48 command. This is detail from a photograph taken by Matthew Logue for the cover of the book.

Underlying concepts: interrupt control, music players, noise, overmodulation, polyphony, parametric filters, chord arpeggios, bitstreams, ADSR, CDMA, DAC, MIDI.

Platforms mentioned: Manchester Mark 1, MIT TX-0, Atari VCS, TRS-80, Apple ][, Acorn Atom, Intellivision, Vectrex, ZX Spectrum, ColecoVision, Oric, C64, Memotech, Adam, Sord, Amstrad CPC, MSX, Einstein, Master System, Apple IIGS, SAM, Atari ST, Megadrive/Genesis, Neo Geo.

Components described: GI AY-8910/8912, Intel 8253, TI SN76477 and SN76489, Atari TIA and POKEY, Commodore SID, SAA1099, Ensoniq DOC 5503.

Games noted: Space War, Computer Space, Space Invaders, Centipede, Gauntlet, Missile Command, Firefox, I Robot, Major_Havoc, Return of the Jedi, Meteor Attack, Manic Miner, Commando, International Karate, Fairlight, Zombie Zombie, TOCA Race Driver.

Further reading

The Essence of Interactive Audio - first chapter abstract.
Sample Replay - next chapter abstract.
Return to the index of chapters.
Click here to get your own copy of Beep To Boom.

Copyright © 2019 Simon N Goodwin     [';']