Specifications

Glossary
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collision In a LAN, if two computers transmit a
packet of data at the same time on the network,
the data can become garbled, which is known as a
collision.
collision detection/avoidance A process used
on a LAN to prevent data packets from interfering
with each other and to determine whether data
packets have encountered a collision and initiate a
resend of the affected packets.
color graphics adapter See CGA.
color palette The colors available to a graphics
adapter for display.
COM port A serial port on a PC that conforms to
the RS-232 standard. See also RS-232.
COMDEX The largest international computer
trade show and conference in the world, managed
by MediaLive International, Inc. See
www.comdex.com for the latest information.
command An instruction that tells the com-
puter to start, stop, or continue an operation.
COMMAND.COM An operating system file that is
loaded last when the computer is booted. This is
the command interpreter or user interface and
program-loader portion of DOS.
command interpreter The operating system
program that controls a computer’s shell or user
interface. The command interpreter for MS-DOS
(and the command-line sessions in Windows
9x/Me) is
COMMAND.COM; the command interpreter
for the graphical shell in Windows versions
through 9x/Me is
WIN.COM; the command inter-
preter for NT-based versions of Windows (including
Windows 2000 and later) is
CMD.COM.
common The ground or return path for an elec-
trical signal. If it’s a wire, it usually is colored black.
common mode noise Noise or electrical distur-
bances that can be measured between a current- or
signal-carrying line and its associated ground.
Common mode noise is frequently introduced to
signals between separate computer equipment com-
ponents through the power distribution circuits. It
can be a problem when single-ended signals are
used to connect different equipment or compo-
nents that are powered by different circuits.
CompactFlash An ATA flash memory card phys-
ical format approximately one third the size of a
standard PC Card. Often abbreviated CF or CF+,
CompactFlash cards are identical in function to
standard ATA Flash PC Cards (PCMCIA) but use
50 pin connectors instead of 68. ATA flash cards
contain built-in disk controller circuitry to enable
the card to function as a solid-state disk drive. CF
cards can plug into a CompactFlash socket or with
an adapter into a standard Type I or II PC Card
(PCMCIA) slot. CF cards are used by many types of
digital cameras.
CompactPCI The PICMG standard for PCI-based
industrial computers, CompactPCI boards plug into
a 220-pin IEC-1076 bus.
compatible 1) In the early days of the PC indus-
try when IBM dominated the market, a term used
to refer to computers from other manufacturers
that had the same features as a given IBM model.
2) In general, software or hardware that conforms
to industry standards or other de facto standards so
that it can be used in conjunction with or in lieu of
other versions of software or hardware from other
vendors in a like manner.
compiler A program that translates a program
written in a high-level language into its equivalent
machine language. The output from a compiler is
called an object program.
complete backup A backup of all information
on a hard disk, including the directory tree
structure.
composite video Television picture information
and sync pulses combined. The complete wave
form of the color video signal composed of chromi-
nance and luminance picture information; blank-
ing pedestal; field, line, and color-sync pulses; and
field-equalizing pulses. Some video cards have an
RCA jack that outputs a composite video signal. See
also RGB.
compressed file A file that has been reduced in
size via one or more compression techniques. See
also archive file.
computer A device capable of accepting data,
applying prescribed processes to this data, and dis-
playing the results or information produced.
Appendix A
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