Glossary 105
expansion card — An add-in card, such as a NIC or SCSI
adapter, that plugs into an expansion-card connector on
the system board. An expansion card adds some
specialized function to the system by providing an
interface between the expansion bus and a peripheral.
expansion-card connector — A connector on the system
board or riser board for plugging in an expansion card.
F — Fahrenheit.
FAT — File allocation table. The file system structure
used by MS-DOS to organize and keep track of file
storage. The Microsoft® Windows® operating systems can
optionally use a FAT file system structure.
flash memory — A type of EEPROM chip that can be
reprogrammed from a utility on diskette while still
installed in a system; most EEPROM chips can only be
rewritten with special programming equipment.
format — To prepare a physical disk or diskette for storing
files. An unconditional format deletes all data stored on
the disk.
FSB — Front-side bus. The FSB is the data path and
physical interface between the processor and the main
memory (RAM).
ft — Feet.
FTP — File transfer protocol.
g — Gram(s).
G — Gravities.
Gb — Gigabit(s); 1024megabits or 1,073,741,824 bits.
GB — Gigabyte(s); 1024megabytes or 1,073,741,824
bytes. However, when referring to physical disk capacity,
the term is usually rounded to 1,000,000,000 bytes.
graphics mode — A video mode that can be defined as x
horizontal by y vertical pixels by z colors.
group — As it relates to DMI, a group is a data structure
that defines common information, or attributes, about a
manageable component.
guarding — A type of data redundancy in which a set of
physical disks stores data and an additional disks stores
parity data. See also mirroring, striping, and RAID.
h — Hexadecimal. A base-16 numbering system, often
used in programming to identify addresses in the system’s
RAM and I/O memory addresses for devices. In text,
hexadecimal numbers are often followed by h.
headless system — A system or device that functions
without having a keyboard, mouse, or monitor attached.
Normally, headless systems are managed over a network
using an Internet browser.
host adapter — A host adapter implements
communication between the system’s bus and the
controller for a peripheral device. (Disk controller
subsystems include integrated host adapter circuitry.) To
add a SCSI expansion bus to your system, you must install
or connect the appropriate host adapter.
hot-pluggable — The ability to remove a system
component or attached device without powering down
the system. While a component may be "hot-pluggable,"
you should never remove a component or device while
data traffic is occurring that involves the component. For
more information, see the documentation for your
specific component or device.
Hz — Hertz.
I/O — Input/output. A keyboard is an input device, and a
monitor is an output device. In general, I/O activity can be
differentiated from computational activity.
ID — Identification.
IDE — Integrated drive electronics. A standard interface
between the system board and storage devices.
integrated mirroring — Provides simultaneous physical
mirroring of two drives. Integrated mirroring functionality
is provided by the system’s hardware. See also mirroring.
internal processor cache — An instruction and data cache
built into the processor.
IP — Internet Protocol.
IPX — Internet package exchange.
IRQ — Interrupt request. A signal that data is about to be
sent to or received by a peripheral device travels by an IRQ
line to the processor. Each peripheral connection must be
assigned an IRQ number. Two devices can share the same
IRQ assignment, but you cannot operate both devices
simultaneously.