Glossary-4 User’s Manual
Glossary
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.
CMOS: Complementary Metal-Oxide Semiconductor. An electronic circuit
fabricated on a silicon wafer that requires very little power.
Integrated circuits implemented in CMOS technology can be tightly
packaged and are highly reliable.
cold start: Starting a computer that is currently off (turning on the power).
COM1, COM2, COM3 and COM4: The names assigned to the serial and
communication ports.
commands: Instructions you enter at the terminal keyboard that direct the
actions of the computer or its peripheral devices.
communications: The means by which a computer transmits and
receives data to and from another computer or device. See parallel
interface; serial interface.