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Glossary
buffer: An area of memory where information is held until it can be
processed. Buffers are frequently used to compensate for the fact
that some parts of the system are faster than others. For example, the
computer sends information to a printer much faster than even the
fastest printer can handle it. A print buffer stores printer information,
enabling the computer to continue with other tasks. As the printer
prints a page, it looks in the buffer to see what to do next.
bus: An electrical circuit that connects the microprocessor with other
parts of the computer, such as the video adapter, disk drives and
ports. It is the highway along which data flows from one device to
another. See also local bus.
busy: A code indicating the number called is busy.
byte: A sequence of eight bits. A byte is the smallest addressable unit of
data. Each byte represents an integer up to 255 in decimal (11111111
in binary, or FF in hexadecimal), or a character (such as a letter,
numeral, or other symbol). See also binary, bit, gigabyte,
hexadecimal, kilobyte, megabyte.
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carrier: A modem converts the digital signals of the personal computer
into analog signals to send them through the telephone line. The
analog signals are "carrier," because they transport the data. The
analog frequency is determined by the individual communication
specifications.
capacity: The amount of information that can be stored in a computer's
memory or on a storage device such as a hard disk, diskette, or
CD-ROM. Capacity is usually measured in terms of kilobytes (KB),
megabytes (MB) or gigabytes (GB). See also gigabyte, kilobyte,
megabyte.
checksum: A method of checking data errors. Data is divided into blocks,
and the total of the data in those blocks is checked to determine
whether the data has been correctly transmitted. The total value is
called checksum.
character: Any letter, number or symbol you can use on the computer.
Some characters are non-printing characters, such as a paragraph
break in a word-processing program. A character occupies one byte
of computer storage.
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