Toshiba PORTEGE M400 User Manual
Page 241
User’s Manual
Glossary--4
Glossary
bit: Derived from "binary digit," the basic unit of information used by the
computer. It is either zero or one. Eight bits is one byte. See also
byte.
board: A circuit board. An internal card containing electronic components,
called chips, which perform a specific function or increase the
capabilities of the system.
boot: Short for bootstrap. A program that starts or restarts the computer.
The program reads instructions from a storage device into the
computer’s memory.
bps: Bits per second. Typically used to describe the data transmission
speed of a modem.
buffer: The portion of the computer’s memory where data is temporarily
stored. Buffers often compensate for differences in the rate of flow
from one device to another.
bus: An interface for transmission of signals, data or electric power.
byte: The representation of a single character. A sequence of eight bits
treated as a single unit; also the smallest addressable unit within the
system.
C
cache memory: High speed memory which stores data that increases
processor speed and data transfer rate. When the CPU reads data
from main memory, it stores a copy of this data in cache memory.
The next time the CPU needs that same data, it looks for it in the
cache memory rather than the main memory, which saves time. The
computer has two cache levels. Level one is incorporated into the
processor and level two resides in external memory.
capacity: The amount of data that can be stored on a magnetic storage
device such as a floppy disk or hard disk. It is usually described in
terms of kilobytes (KB), where one KB = 1024 bytes and megabytes
(MB), where one MB = 1024 KB.
card: Synonym for board. See board.
CardBus: An industry standard bus for 32-bit PC cards.
CD-ROM: A Compact Disc-Read Only Memory is a high capacity disc that
can be read from but not written to. The CD-ROM drive uses a laser,
rather than magnetic heads, to read data from the disc.
CD-R: A Compact Disc-Recordable disc can be written once and read
many times. See also CD-ROM.
CD-RW: A Compact Disc-ReWritable disc can be rewritten many times.
See also CD-ROM.
character: Any letter, number, punctuation mark, or symbol used by the
computer. Also synonymous with byte.
chassis: The frame containing the computer.
chip: A small semiconductor containing computer logic and circuitry for
processing, memory, input/output functions and controlling other
chips.