NEC POWERMATE 5100 - SERVICE, Service Manual

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4 Glossary
bit
Binary digit. The smallest unit of computer data. A single digital piece of
information, generally represented by the numeral 0 or 1. Usually the transition
between the states of +5V and -5V within a computer, the charge of a transistor in
an integrated circuit, or the change in polarity of a magnetic region on a disk. See
byte. Data compression schemes can enable the transmission of more than one bit
per voltage transition.
bit block transfer
Moving part of a screen image as a single block rather than moving a pixel at a
time. Bit block transfers are much faster than moving the same pixels individually,
and it is common in accelerated video cards.
bitBLT
Bit Block Transfer.
bitmap
Any occurrence where a single location in memory and a single pixel correspond.
Usually applies to screen or printer output. .BMP files are bitmapped graphics files.
bits per second
(bps) A unit of transmission. Also called baud rate.
block
A contiguous section of bits considered as a whole, especially in memory. On a
disk, the data in one sector; in modem data transfer, the bits between checksums.
board
Printed circuit board. Board onto which computer components are soldered and thin
wires are printed to connect the components.
boot
To start up a computer. The computer is generally booted in one of three ways: by
turning on the power switch (cold boot), by pressing the reset switch, or by
simultaneously pressing the Ctrl, Alt, and Del keys (warm boot). Booting the
system after it has already been powered up and booted is referred to as rebooting.
Also the process of booting itself. Boot is from “bootstrap,” a reference to a
computer’s ability to set itself up, or pull itself up by its own ‘bootstraps.’ See cold
boot and warm boot.
bootable device
Any type of hardware that carries the information (software) required by the
computer to start properly. This device must also have the capacity to be
recognized by the computer in the first stages of the boot process.
boot block
The part of a disk that contains the software (such as the operating system loader)
that enables the computer to start.