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tool used to create a hole, usually in some hard substance, by its rotary or hammering action. Many different tools make up the drill family. The awl is a pointed instrument used for piercing small holes.
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part of the bridle of a horse’s harness. Bits appeared in the late Bronze Age, when the horse was first used as a beast of burden. Originally they were made of soft material (sinew) and were secured in the horse’s mouth by bone cheekpieces. Bronze bits and cheekpieces appeared at the turn of the first millennium B.C., and iron bits were prevalent in the seventh and sixth centuries B.C. Iron snaffles with movable rings at the ends were used in Rus’. In the late Middle Ages, bits were very intricate and sometimes richly ornamented. Modern bits consist of two parts and have snaffle rings.
A binary digit. In the computer, electronics, and communications fields, “bit” is generally understood as a shortened form of “binary digit.” In a numerical binary system, a bit is either a 0 or 1. Bits are generally used to indicate situations that can take one of two values or one of two states, for example, on and off, true or false, or yes or no. If, by convention, 1 represents a particular state, then 0 represents the other state. For example, if 1 stands for “yes,” then 0 stands for “no.”
In a computer system a bit is thought of as the basic unit of memory where, by convention, only either a 0 or 1 can be stored. In a computer memory, consecutive bits are grouped to form smaller or larger “units” of memory. Depending upon the design of the computer, units up to 64 bits long have been considered. Although there is common agreement as to the number of bits that make up a byte, for larger memory units the terminology depends entirely on the convention used by the manufacturer. In all of these units the leftmost bit is generally called the most significant bit (msb) and the rightmost the least significant bit (lsb).
Bytes and larger units can be used to represent numerical quantities. In these cases the most significant bit is used to indicate the “sign” of the value being represented. By convention a 0 in the msb represents a positive quantity; a 1 represents a negative quantity. Depending on the convention used to represent these numbers, the remaining bits may then be used to represent the numerical value. In addition to numerical quantities, bytes are used to represent characters inside a computer. These characters include all letters of the English alphabet, the digits 0 through 9, and symbols such as comma, period, right and left parentheses, spaces, and tabs. Characters can be represented using ASCII (American Standard Code for Information Interchange) or EBCDIC (Extended Binary Coded Decimal Interchange Code). The latter is used by some mainframe computers. Computers are set up to handle only one of these two character codes. Generally, the internal representation of a character is different in the two codes. For instance, in ASCII the plus sign is represented by the numerical sequence 00101011, and in EBCDIC, by 01001110.
bit2 Maths Computing
The unit of information; the amount of information obtained by asking a yes-or-no question; a computational quantity that can take on one of two values, such as false and true or 0 and 1; the smallest unit of storage - sufficient to hold one bit.
A bit is said to be "set" if its value is true or 1, and "reset" or "clear" if its value is false or 0. One speaks of setting and clearing bits. To toggle or "invert" a bit is to change it, either from 0 to 1 or from 1 to 0.
The term "bit" first appeared in print in the computer-science sense in 1949, and seems to have been coined by the eminent statistician, John Tukey. Tukey records that it evolved over a lunch table as a handier alternative to "bigit" or "binit".
See also flag, trit, mode bit, byte, word.
bit(1) (Built-In Test) See BIST.
(2) (BInary digiT) The smallest element of computer storage. It is a single digit in a binary number (0 or 1). The bit is physically a transistor or capacitor in a memory cell, a magnetic domain on disk or tape, a reflective spot on optical media or a high or low voltage pulsing through a circuit.
Bits for Transmission
Bits are widely used as a measurement for network transmission. One hundred megabits per second means that 100 million pulses are transmitted per second.
Bytes for Storage
Groups of bits make up storage units in the computer, called "characters," "bytes," or "words," which are manipulated as a group. The most common is the byte, made up of eight bits and equivalent to one alphanumeric character. Measurements for storage components, such as disks, files and databases, are given in bytes rather than bits. See space/time.
|Storage - Making it Smaller|
|Making the spot or cell smaller increases the storage capacity. Our disks hold staggering amounts of data compared to 10 years ago, yet we still want more. Look up holographic storage for a look into a fascinating future of storage technology.|
|Transmission - Making it Faster|
|The bit is transmitted as a pulse of high or low voltage. Speed is increased by making the transistors open and close faster, which is a combination of making the microscopic elements within the transistor smaller and more durable.|