NEC POWERMATE ES 5200 - SERVICE, Руководство по обслуживанию

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6 Glossary
chassis
The metal frame to which the electronic components of the computer (such as the
system board, power supply, and drive bays) are attached. The chassis goes inside
the system unit cover.
checksum
A number, calculated from a block of data, used to verify the integrity of that data.
For example, a modem could send a block of data and include the number of 1’s
that occur in the block. The receiving modem could count the number of 1’s it
receives and compare its own number with the transmitted number. If the numbers
are the same, the transmission was probably OK.
clock
Electronic timer (oscillator) used to synchronize computer operations. The
oscillator generates the timing pulses that coordinate and enable the flow of data
within a digital device. Also a circuit powered by battery that keeps track of the
date and time for human and various system requirements.
clock speed
The frequency at which a clock oscillates. In microcomputers, measured in MHz.
The faster the clock, the faster the computer can compute.
CMOS
Complementary Metal Oxide Semiconductor. A chip on the system board that
contains nonvolatile memory. CMOS is backed up by an internal lithium battery
that preserves clock/calendar data and system configuration parameters stored in
CMOS.
codec
Coder-decoder. Used primarily with Internet phone and video conferencing
products, this software compresses digitized data and decompresses it at the other
end, allowing for faster data transfer and less delays
cold boot
Process of starting up the computer by turning on the power. If power is already on,
the process means to turn off the computer and turn it on again. A cold boot
reinitializes all devices.
compression
Any scheme for recording data with fewer bits. For example, stating how many
times something occurs can be shorter than stating each occurrence. It is shorter to
say “print a million white pixels” than to say “print white pixel number one, print
white pixel number two . . .”
D
default
The system’s factory setting for a specific device feature or system function. A
setting that a computer uses if it has not been modified by a user.