Specifications
8
Appendix A Glossary
the Athlon XP is designed mainly for single proces-
sor applications. All three use the improved
Thoroughbred core and 3DNow! Professional multi-
media extensions. The Athlon XP processors
include AMD’s new QuantiSpeed design for faster
internal operation and are rated by their perfor-
mances relative to the Intel Pentium 4, rather than
by their clock speeds. For example, the Athlon XP
2600+, which performs comparably to the Pentium
4 2.6GHz processor, runs at a clock speed of about
2.1GHz.
Athlon 64 An AMD processor (code-named
Clawhammer) that includes the standard 32-bit x86
instruction set as well as 64-bit extensions. It uses a
new ball grid array socket called Socket 754; an inte-
grated DDR memory controller (instead of using the
North Bridge for memory connections); an
improved version of the AMD-developed
HyperTransport connection to AGP, PCI, and other
components; and an improved heatsink-mounting
solution. It supports MMX and AMD 3DNow!
Instructions for multimedia and uses a performance-
rating system similar to that used by 32-bit Athlon
processors. See also Athlon. See also Socket 754.
Athlon 64 FX An AMD processor based on the
Athlon 64, but offering an integrated dual-channel
memory controller, faster clock speeds, and a 1MB
memory cache in all models. Initial versions used
Socket 940, but later models use Socket 939, AM2
and F. See also Socket 939, Socket AM2, Socket F and
Socket 940.
Athlon 64 X2 A dual-core version of the AMD
Athlon 64 processor that features separate L2 mem-
ory caches for each core and an integrated crossbar
memory switch for fast transfer of information
between each core. This processor uses Socket 939
and AM2. See also Socket 939.
ATM (asynchronous transfer mode) A high-
bandwidth, low-delay, packet-like switching and
multiplexing technique. Usable capacity is seg-
mented into fixed-size cells consisting of header
and information fields, allocated to services on
demand.
attribute byte A byte of information, held in
the directory entry of any file or folder, that
describes various attributes of the file or folder,
such as whether it is read-only or has been backed
up since it last was changed. Attributes can be set
by the DOS
ATTRIB command or with Windows
Explorer.
ATX A motherboard and power supply form fac-
tor standard designed by Intel in 1995. It is charac-
terized by a double row of rear external I/O
connectors on the motherboard, a single keyed
power supply connector, memory and processor
locations that are designed not to interfere with the
installation of adapter cards, and an improved cool-
ing flow. The current specification—ATX 2.0—was
introduced in December 1996.
audio A signal that can be heard, such as
through the speaker of the PC. Many PC diagnostic
tests use both visual (onscreen) codes and audio
signals.
audio frequencies Frequencies that can be
heard by the human ear (approximately
20Hz–20,000Hz).
auto-answer A setting in modems enabling
them to answer incoming calls over the phone
lines automatically.
auto-dial A feature in modems enabling them to
dial phone numbers without human intervention.
auto-disconnect A modem feature that enables
a modem to hang up the telephone line when the
modem at the other end hangs up.
auto-redial A modem or software feature that
automatically redials the last number dialed if the
number is busy or does not answer.
AUTOEXEC.BAT A special batch file DOS and
Windows 9x execute at startup. Contains any num-
ber of DOS commands that are executed automati-
cally, including the capability to start programs at
startup. See also batch file.
autoloader A tape or Iomega REV–based drive
that contains multiple media cartridges and a
mechanism for removing and inserting cartridges as
each cartridge is filled.
automatic head parking Disk drive head
parking performed whenever the drive is powered
off. Found in all modern hard disk drives with a
voice-coil actuator.
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