Cloud History Software Engineering

The Byte – 1956 AD

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The Byte

Werner Buchholz (b. 1922), Louis G. Dooley (dates unavailable)

“Designers of the early binary computers faced a fundamental question: how should the computers’ storage be organized? The computers stored information in bits, but computer users didn’t want to write programs that manipulated bits; they wanted to solve math problems, crack codes, and generally work with larger units of information. The memory of decimal computers such as ENIAC and the UNIVAC I was organized in groups of 10 alphanumeric digits, called words. The binary computers also organized their memory into words, but these groups of bits were called bytes.”

Unit systemunits derived from bit
Unit ofdigital information, data size
SymbolB or (when referring to exactly 8 bits) o

“It appears that the word byte was coined simultaneously in 1956 by Werner Buchholz at IBM, working on the IBM STRETCH (the world’s first supercomputer), and by Louis G. Dooley and others at MIT Lincoln Lab working on the SAGE air-defense system. In both cases, they used the word byte to describe the inputs and outputs of machine instructions that could operate on less than a full word. The STRETCH had 60-bit words and used 8-bit bytes to represent characters for its input/output system; the SAGE had instructions that could operate on 4-bit bytes.”

“The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer[1][2] and for this reason it is the smallest addressable unit of memory in many computer architectures. To disambiguate arbitrarily sized bytes from the common 8-bit definition, network protocol documents such as The Internet Protocol (RFC 791)(1981) refer to an 8-bit byte as an octet.[3]

“Over the next 20 years, the definition of a byte was somewhat fluid. IBM used 8-bit bytes with its System/360 architecture, and 8-bit groups were the standard for AT&T’s long-distance digital telephone lines. DEC, on the other hand, successfully marketed a series of computers with 18-bit and 36-bit words, including the PDP-7 and the PDP-10, which both utilized 9-bit bytes.”

“This lack of consistency resulted in the early Internet standards avoiding the word byte entirely. Instead, the word octet is used to describe a group of 8 bits sent over a computer network, a usage that survives to this day in Internet standards.”

“Nevertheless, by the 1980s, the acceptance of 8-bit bytes was almost universal—largely a result of the microcomputer revolution, because micros used 8-bit bytes almost exclusively. In part, that’s because 8 bits is an even power of 2, which makes it somewhat easier to design computer hardware with 8-bit bytes than with 9-bit bytes.”

“Today the era of 9-bit bytes is all but forgotten. And what about collections of 4 bits? Today these are called a nibble (sometimes spelled nybble).”

Multiples of bytes:

Multiples of bytes

Prefixes for multiples of bits (bit) or bytes (B)


“Today’s computers most frequently use bytes consisting of 8 bits, represented by 1s and 0s.”

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