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A Bit In Computer

author
Brent Mccoy
• Friday, 06 November, 2020
• 7 min read

The bit is a basic unit of information in computing and digital communications. The bit represents a logical state with one of two possible values.

bit computer basic hackaday io
(Source: hackaday.io)

Contents

Frequently, half-, full-, double- and quad-words consist of a number of bytes which is a low power of two. Ralph Hartley suggested the use of a logarithmic measure of information in 1928.

Claude E. Shannon first used the word bit in his seminal 1948 paper A Mathematical Theory of Communication “. He attributed its origin to John W. Turkey, who had written a Bell Labs memo on 9 January 1947 in which he contracted “binary information digit” to simply bit “.

Manner Bush had written in 1936 of “bits of information” that could be stored on the punched cards used in the mechanical computers of that time. The first programmable computer, built by Konrad Use, used binary notation for numbers.

For devices using positive logic, a digit value of 1 (or a logical value of true) is represented by a more positive voltage relative to the representation of 0. The specific voltages are different for different logic families and variations are permitted to allow for component aging and noise immunity.

In the earliest non-electronic information processing devices, such as Jacquard's loom or Babbage's Analytical Engine, a bit was often stored as the position of a mechanical lever or gear, or the presence or absence of a hole at a specific point of a paper card or tape. The first electrical devices for discrete logic (such as elevator and traffic light control circuits, telephone switches, and Konrad Use's computer) represented bits as the states of electrical relays which could be either “open” or “closed”.

bit computer
(Source: www.youtube.com)

When relays were replaced by vacuum tubes, starting in the 1940s, computer builders experimented with a variety of storage methods, such as pressure pulses traveling down a mercury delay line, charges stored on the inside surface of a cathode-ray tube, or opaque spots printed on glass discs by photolithographic techniques. The most common is the unit byte, coined by Werner Buchwald in June 1956, which historically was used to represent the group of bits used to encode a single character of text (until UTF-8 multi byte encoding took over) in a computer and for this reason it was used as the basic addressable element in many computer architectures.

The trend in hardware design converged on the most common implementation of using eight bits per byte, as it is widely used today. However, because of the ambiguity of relying on the underlying hardware design, the unit octet was defined to explicitly denote a sequence of eight bits.

Computers usually manipulate bits in groups of a fixed size, conventionally named words “. In the 21st century, retail personal or server computers have a word size of 32 or 64 bits.

The International System of Units defines a series of decimal prefixes for multiples of standardized units which are commonly also used with the bit and the byte. The prefixes' kilo (10 3) through gotta (10 24) increment by multiples of 1000, and the corresponding units are the kilo bit (bit) through the cohabit (Bit).

The reason given is: it cites a fact about global information content in computers from 2007. Please update this section to reflect recent events or newly available information.

dell
(Source: www.1000bit.it)

When the information capacity of a storage system or a communication channel is presented in bits or bits per second, this often refers to binary digits, which is a computer hardware capacity to store binary data (0 or 1, up or down, current or not, etc.). If the value is completely predictable, then the reading of that value provides no information at all (zero entropic bits, because no resolution of uncertainty occurs and therefore no information is available).

Using an analogy, the hardware binary digits refer to the amount of storage space available (like the number of buckets available to store things), and the information content the filling, which comes in different levels of granularity (fine or coarse, that is, compressed or uncompressed information). For example, it is estimated that the combined technological capacity of the world to store information provides 1,300 exabytes of hardware digits in 2007.

However, when this storage space is filled and the corresponding content is optimally compressed, this only represents 295 exabytes of information. In the 1980s, when bit mapped computer displays became popular, some computers provided specialized bit block transfer instructions to set or copy the bits that corresponded to a given rectangular area on the screen.

In most computers and programming languages, when a bit within a group of bits, such as a byte or word, is referred to, it is usually specified by a number from 0 upwards corresponding to its position within the byte or word. Other units of information, sometimes used in information theory, include the natural digit also called a Nat or nit and defined as log 2 e ( 1.443) bits, where e is the base of the natural logarithms ; and the it, ban, or Hartley, defined as log 2 10 ( 3.322) bits.

Conversely, one bit of information corresponds to about LN 2 ( 0.693) NATO, or log 10 2 ( 0.301) Hartley. Some authors also define a bi nit as an arbitrary information unit equivalent to some fixed but unspecified number of bits.

kaypro screen front computer computers punk phosphor bit 1000 ii which 1000bit does
(Source: www.1000bit.it)

Anderson, John B.; Johansson, Rolf (2006), Understanding Information Transmission ^ Hay kin, Simon (2006), Digital Communications ^ IEEE Std 260.1-2004 ^ “Units: B”. If the base 2 is used the resulting units may be called binary digits, or more briefly bits, a word suggested by J. W. Turkey.

^ National Institute of Standards and Technology (2008), Guide for the Use of the International System of Units. Archived 3 June 2016 at the Payback Machine ^ Beer, Robert William (2000-08-08).

With IBM's STRETCH computer as background, handling 64-character words divisible into groups of 8 (I designed the character set for it, under the guidance of Dr. Werner Buchwald, the man who DID coin the term byte for an 8- bit grouping). Most important, from the point of view of editing, will be the ability to handle any characters or digits, from 1 to 6 bits long the Shift Matrix to be used to convert a 60- bit word, coming from Memory in parallel, into characters, or bytes as we have called them, to be sent to the Adder serially.

Assume that it is desired to operate on 4 bit decimal digits, starting at the right. The first reference found in the files was contained in an internal memo written in June 1956 during the early days of developing Stretch.

The possibility of going to 8 bit bytes was considered in August 1956 and incorporated in the design of Stretch shortly thereafter. The first published reference to the term occurred in 1959 in a paper “Processing Data in Bits and Pieces” by G A Black, F P Brooks Jr and W Buchwald in the IRE Transactions on Electronic Computers, June 1959, page 121.

kaypro computer computers 1000bit
(Source: www.1000bit.it)

The notions of that paper were elaborated in Chapter 4 of Planning a Computer System (Project Stretch), edited by W Buchwald, McGraw-Hill Book Company (1962). The rationale for coining the term was explained there on page 40 as follows: Byte denotes a group of bits used to encode a character, or the number of bits transmitted in parallel to and from input-output units.

System/360 took over many of the Stretch concepts, including the basic byte and word sizes, which are powers of 2. For economy, however, the byte size was fixed at the 8 bit maximum, and addressing at the bit level was replaced by byte addressing.

Black, Gerrit Anne ; Brooks, Jr., Frederick Phillips ; Buchwald, Werner (1962), “Chapter 4: Natural Data Units” (PDF), in Buchwald, Werner (ed. 39–40, LCC 61-10466, archived from the original (PDF) on 2017-04-03, retrieved 2017-04-03 ^ Beer, Robert William (1959).

The book introduces Claude Shannon and basic concepts of Information Theory to children 8 and older using relatable cartoon stories and problem-solving activities. “The World's Technological Capacity to Store, Communicate, and Compute Information” Archived 2013-07-27 at the Payback Machine, especially Supporting online material Archived 2011-05-31 at the Payback Machine, Martin Hilbert and Priscilla López (2011), Science, 332(6025), 60-65; free access to the article through here: martinhilbert.net/WorldInfoCapacity.html Bhattacharya, Amitabh (2005).

It's a single unit of information with a value of either 0 or 1 (off or on, false or true, low or high). Anything larger and the computer would need to break up the number into smaller pieces.

heathkit computer 1000bit
(Source: www.1000bit.it)

Below is a listing of byte values in comparison to other units of measurements. Bit (b)Value A bit in a Bit (b)1Bits in a Nibble (N)4Bits in a Byte (B)8Bits in a Kilo bit (Kb)1,000Bits in a Kilobyte (KB)8,000Bits in a Exhibit (KIB)1,024Bits in a Kilobyte (KiB)8,192Bits in a Megabit (Mb)1,000,000Bits in a Megabyte (MB)8,000,000Bits in a Megabit (MIB)1,049,000Bits in a Megabyte (MiB)8,389,000Bits in a Gigabit (GB)1,000,000,000Bits in a Gigabyte (GB)8,000,000,000Bits in a Gibbet (GIB)1,000,000,000Bits in a Gigabyte (GiB)8,590,000,000Bits in a Terabit (Tb)1,000,000,000,000Bits in a Terabyte (TB)8,000,000,000,000Bits in a Terabit (Tie)1,100,000,000,000Bits in a Terabyte (Tie)8,796,000,000,000Bits in a Megabit (Pb)1,000,000,000,000,000Bits in a Petabyte (PB)8,000,000,000,000,000Bits in a Exhibit (PIB)1,126,000,000,000,000Bits in a Petabyte (PIB)9,007,200,000,000,000Bits in an Exact (Ex)1,000,000,000,000,000,000Bits in an Exabyte (EX)8,000,000,000,000,000,000Bits in an Exhibit (EIB)1,152,921,500,000,000,000Bits in an Exabyte (EIB)9,223,372,040,000,000,000Bits in a Zettabyte (LB)8,000,000,000,000,000,000,000Bits in a Zettabyte (YB)8,000,000,000,000,000,000,000,000 Although bit is an acronym, it can be written in all uppercase like most acronyms or as all lowercase.

When deciding what style to use for your writing, make sure to remain consistent. Like most style guides, Computer Hope chooses to write bit in all lowercase.

The term was first used by John Turkey, a leading statistician and adviser to five U.S. presidents, in a 1946 memo for Bell Labs. His recommendation was the most natural-sounding portmanteau that had been proposed at the time, so it gained popularity and was shortly thereafter codified in A Mathematical Theory of Communication by mathematician Claude E. Shannon.

More meaningful information is obtained by combining consecutive bits into larger units such as bytes, kilobytes, gigabytes, and megabytes. Bits are also used to describe how quickly data is transferred across a network, usually as kilo bits per second (KBS), megabits per second (Mbps), or in rare cases, gigabits per second (GPS).

To put this in context, a feature-length, high definition film usually requires about 5 Mbps for uninterrupted streaming. Multiple bytes (and by extension, bits) can also be expressed using binary prefixes with base 2 math, although it is much less common because of its complexity.

kaypro
(Source: www.1000bit.it)

The terms “bits” and “bytes” are often confused and are even used interchangeably since they sound similar and are both abbreviated with the letter “B.” It is important not to confuse these two terms, since any measurement in bytes contains eight times as many bits.

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