Toshiba Tecra A3X - Manual (Page 180)

User’s Manual Glossary-3
Glossary
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 commands 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 components,
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 memory, which saves time. The
computer has two cache levels. Level one is incorporated into the
processor and level two resides in external memory.