4 Glossary
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.
boot sector
The part of the boot block that contains the operating system loader, a program that starts by
itself and loads the operating system.
bps
Bits per second. The number of bits of data that can be transmitted in one second. Because
data compression schemes enable more than one bit per voltage transition, bps is equivalent
to baud only if no compression is used.
buffer
A place, especially in RAM, for the temporary storage of data for the purpose of speeding
up an operation such as printing or drive access. Data from a buffer is available more
quickly than data from where the buffer got it. Typically buffers get data before it is needed
so it is ready quickly when needed. Similar to cache.
burst mode
When a device seizes control of the bus, sends data, then relinquishes control of the bus.
Any time a device sends data without interruption instead of taking turns with other devices.