external cache memory
A RAM cache using SRAM chips. Because SRAM chips
operate at several times the speed of DRAM chips, the
microprocessor can retrieve data and instructions faster
from external cache memory than from RAM.
Abbreviation for Fahrenheit.
Acronym for file allocation table. The file system structure
used by MS-DOS to organize and keep track of file storage.
The Microsoft Windows NT
systems can optionally use a FAT file system structure.
Abbreviation for Federal Communications Commission.
A type of EEPROM chip that can be reprogrammed from
a utility on diskette while still installed in a computer; most
EEPROM chips can only be rewritten with special pro-
To prepare a hard-disk drive or diskette for storing files.
An unconditional format deletes all data stored on the disk.
The format command in MS-DOS 5.0 or higher includes an
option that allows you to unformat a disk, if you have not yet
used the disk for file storage.
Abbreviation for feet.
Abbreviation for gram(s).
Abbreviation for gravities.
Abbreviation for gigabyte(s). A gigabyte equals 1,024 mega-
bytes or 1,073,741,824 bytes.
See video mode.
Dell PowerEdge 2200 Systems User's Guide
Acronym for graphical user interface.
Abbreviation for hexadecimal. A base-16 numbering sys-
tem, often used in programming to identify addresses in
the computer's RAM and I/O memory addresses for de-
vices. The sequence of decimal numbers from 0 through
16, for example, is expressed in hexadecimal notation as:
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F, 10. In text,
hexadecimal numbers are often followed by h or preceded
by 0x. MS-DOS conventional memory—the first 640 KB of
memory addresses—is from 00000h to 9FFFFh; the MS-DOS
upper memory area—memory addresses between 640 KB and
1 MB—is from A0000h to FFFFFh.
A metal plate with metal pegs or ribs that help dissipate
heat. Some microprocessors include a heat sink.
Abbreviation for high memory area. The first 64 KB of
extended memory above 1 MB. A memory manager that
conforms to the XMS can make the HMA a direct exten-
sion of conventional memory. See also conventional
memory, memory manager, upper memory area, and
A host adapter implements communication between the
computer's bus and the controller for a peripheral. (Hard-
disk drive controller subsystems include integrated host
adapter circuitry.) To add a SCSI expansion bus to your
system, you must install the appropriate host adapter.
Abbreviation for the High Performance File System option
in the OS/2 and Windows NT operating systems.
Abbreviation for hertz.
Abbreviation for input/output. The keyboard and a printer,
for example, are I/O devices. In general, I/O activity can
be differentiated from computational activity. For exam-
ple, when a program sends a document to the printer, it is
engaging in I/O activity; when the program sorts a list of
terms, it is engaging in computational activity.