HP Vectra VL6 7 Administrator's Manual page 108

Glossary
referred to as the AT bus. The XT bus
is 8 bits wide and the AT bus is 16 bits
wide. The AT bus has become a de
facto industry standard.
ISR Interrupt Service Routine. A
sequence of software instructions
that are executed as a result of a
hardware interrupt.
jumper A plastic and metal shorting
bar that slides over two or more
electrical contacts to set certain
conditions. Older (legacy) ISA
network adapter cards require the
user to set the DMA channel and IRQ
using jumpers on the card itself.
Newer network cards no longer
require the user to set jumpers. The
DMA channel, IRQ, and so on, can be
set with software or are set
automatically using Plug and Play.
keyword A word reserved for
special use by a program.
kilobyte A unit of information
consisting of 1,024 bytes.
Abbreviation: KB.
LAN Local Area Network. A general-
purpose communications network
that interconnects a variety of devices
within a limited geographical area. A
LAN might connect computers on
adjacent desks, within a building, or
within several buildings of a campus.
LAN activity light A light on the
front panel of some Vectra PCs which
indicates when the PC is accessing
the network.
legacy A term used to refer to older
hardware and software still in use. In
the Plug and Play context, legacy
means the installed base of adapter
cards that do not conform to the Plug
and Play standard.
LocalTalk The cabling scheme
supported by the AppleTalk network
protocol for Apple Macintosh
computers. LocalTalk is a 230-Kbs
medium access method which is
relatively slow, but popular because it
is inexpensive and easy to install and
maintain.
Loopback Test A diagnostic test in
which a transmitted signal is returned
to the sending device after passing
through all, or a part of, a network.
Loopback provides a way of
comparing the transmitted signal with
the returned signal for integrity.
MAC Media Access Control. The
MAC sublayer defines the medium-
independent capability for frame
transmission and reception using the
CSMA/CD_CD access method.
MAC address A 12-digit
hexadecimal number that identifies a
specific network node and allows
messages to be directed to that node
only. Because the IEEE has assigned
identifiers for each hardware
manufacturer, no two pieces of
equipment have the same address.
Your MAC address is unique.
English 108