Sound
The epitome of the Apple II design philosophy was the Apple II sound circuitry. Rather than having a dedicated sound-synthesis chip, the Apple II had a toggle circuit that could only emit a click through a built-in speaker or a line out jack; all other sounds (including two, three and, eventually, four-voice music and playback of audio samples and speech synthesis) were generated entirely by software that clicked the speaker at just the right times. Not for nearly a decade would an Apple II be released with a dedicated sound chip (though with six expansion slots, users could add sound functionality via a soundcard like the Mockingboard). Similar techniques were used for cassette storage: the cassette output worked the same as the speaker, and the input was a simple zero-crossing detector that served as a relatively crude (1-bit) audio digitizer. Routines in the ROM were used to encode and decode data in frequency-shift keying for the cassette.
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Famous quotes containing the word sound:
“Envy awakens at the sound of a distant laugh.”
—Mason Cooley (b. 1927)
“The Young Man’s Best Companion, The Farrier’s Sure Guide, The Veterinary Surgeon, Paradise Lost, The Pilgrim’s Progress, Robinson Crusoe, Ash’s Dictionary, and Walkingame’s Arithmetic, constituted his library; and though a limited series, it was one from which he had acquired more sound information by diligent perusal than many a man of opportunities had done from a furlong of laden shelves.”
—Thomas Hardy (1840–1928)
“Philosophy ... does not talk, but write, or, when it comes personally before an audience, lecture or read; and therefore it must be read to-morrow, or a thousand years hence. But the talker must naturally be attended to at once; he does not talk on without an audience; the winds do not long bear the sound of his voice.”
—Henry David Thoreau (1817–1862)