Toshiba A40 Series - Manual (Page 271)

Glossary-3
G
LOSSARY
ASCII: American Standard Code for
Information Interchange. ASCII code is
a set of 256 binary codes that represent
the most commonly used letters,
numbers, and symbols.
async: Short for asynchronous.
asynchronous: Lacking regular time
relationship. As applied to computer
communications, asynchronous refers
to the method of transmitting data that
does not require a steady stream of
bits to be transmitted at regular time
intervals.
B
backup: A duplicate copy of files kept
as a spare in case the original is
destroyed.
batch file: A file that can be executed
from the system prompt containing a
sequence of operating system com-
mands or executable files.
binary: The base two number system
composed of zeros and ones (off or
on), used by most digital computers.
The right-most digit of a binary number
has a value of 1, the next a value of 2,
then 4, 8, 16, and so on. For example,
the binary number 101 has a value of 5.
See also ASCII.
BIOS: Basic Input Output System.
The firmware that controls data flow
within the computer. See also firmware.
bit: Derived from "binary digit," the
basic unit of information used by the
computer. It is either zero or one. Eight
bits is one byte. See also byte.
board: A circuit board. An internal
card containing electronic compo-
nents, called chips, which perform a
specific function or increase the
capabilities of the system.
boot: Short for bootstrap. A program
that starts or restarts the computer.
The program reads instructions from a
storage device into the computer’s
memory.
bps: Bits per second. Typically used
to describe the data transmission
speed of a modem.
buffer: The portion of the computer’s
memory where data is temporarily
stored. Buffers often compensate for
differences in the rate of flow from one
device to another.
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
cache memory