It would be stretching our imagination to suggest that Sir Francis had digital audio on his minde (sic) when he wrote the prophetic words
Sir Francis Bacon, 1623
...a man may express and signifie the intentions of his minde, at any distance... by... objects... capable of a twofold difference onely.
Nonetheless, this basic idea forms the basis of everything we do in digital computing, digital communications, and digital audio/video. In 1832, Samuel F. B. Morse used the very same idea to propose that telegram words be coded into binary addresses or binary codes that could be transmitted over telegraph lines and decoded at the receiving end to unravel the telegram. Morse abandoned his scheme, illustrated in Figure 1, as too complicated and, in 1838, proposed his fabled Morse code for coding letters (instead of words) into objects (dots, dashes, spaces) capable of a threefold difference onely (sic).
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The basic idea of Figure 1 is used today in cryptographic systems,
where the “address
In this chapter we study three fundamental questions in the construction of binary addresses or binary codes. First, what are plausible schemes for mapping symbols (such as words, letters, computer instructions, voltages, pressures, etc.) into binary codes? Second, what are plausible schemes for coding likely symbols with short binary words and unlikely symbols with long words in order to minimize the number of binary digits (bits) required to represent a message? Third, what are plausible schemes for “coding” binary words into longer binary words that contain “redundant bits” that may be used to detect and correct errors? These are not new questions. They have occupied the minds of many great thinkers. Sir Francis recognized that arbitrary messages had binary representations. Alan Turing, Alonzo Church, and Kurt Goedel studied binary codes for computations in their study of computable numbers and algorithms. Claude Shannon, R. C. Bose, Irving Reed, Richard Hamming, and many others have studied error control codes. Shan- non, David Huffman, and many others have studied the problem of efficiently coding information.
In this chapter we outline the main ideas in binary coding and illustrate the role that binary coding plays in digital communications. In your subsequent courses in electrical and computer engineering you will study integrated circuits for building coders and decoders and mathematical models for designing good codes.
"Reviewer's Comments: 'I recommend this book as a "required primary textbook." This text attempts to lower the barriers for students that take courses such as Principles of Electrical Engineering, […]"