Specifications
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Appendix A Glossary
DVD+R/RW are the most compatible, fastest, most
capable, and most popular of all the recordable
DVD formats. See also DVD+R.
DVD±RW A DVD drive capable of reading and
writing to both DVD+R/RW and DVD-R/RW media.
Some of these drives also support some or all of
these media types: DVD+R DL, DVD-R DL, and
DVD-RAM.
DVI (Digital Video Interactive) A standard
that was originally developed at RCA Laboratories
and sold to Intel in 1988. DVI integrates digital
motion, still video, sound, graphics, and special
effects in a compressed format. DVI is a highly
sophisticated hardware compression technique used
in interactive multimedia applications.
DVI (Digital Visual Interface) The current de
facto standard for LCD displays developed by the
Digital Display Working Group in April 1999.
DVI-D provides digital signals only, whereas DVI-I
(which is more common) provides both digital and
analog signals. A DVI-I connector can be converted
to VGA with an external adapter.
Dvorak keyboard A keyboard design by August
Dvorak that was patented in 1936 and approved by
ANSI in 1982. Provides increased speed and com-
fort and reduces the rate of errors by placing the
most frequently used letters in the center for use by
the strongest fingers. Finger motions and awkward
strokes are reduced by more than 90% in compari-
son with the familiar QWERTY keyboard. The
Dvorak keyboard has the five vowel keys (A, O, E,
U, I) together under the left hand in the center row
and the five most frequently used consonants (D,
H, T, N, S) under the fingers of the right hand.
dynamic execution A processing technique
that enables the processor to dynamically predict
the order of instructions and execute them out of
order internally if necessary for an improvement in
speed. Uses these three techniques: Multiple Branch
Prediction, Data Flow Analysis, and Speculative
Execution.
E2000 Also called Energy 2000, this is a Swiss-
developed standard for power management that
calls for computer monitors to use only 5 watts of
power when in standby mode.
EBCDIC (Extended Binary Coded Decimal
Interchange Code) An IBM-developed, 8-bit
code for the representation of characters. It allows
256 possible character combinations within a single
byte. EBCDIC is the standard code on IBM mini-
computers and mainframes, but not on the IBM
microcomputers, where ASCII is used instead.
ECC (error correcting code) A type of system
memory or cache that is capable of detecting and
correcting some types of memory errors without
interrupting processing.
ECP (enhanced capabilities port) A type of
high-speed parallel port jointly developed by
Microsoft and Hewlett-Packard that offers improved
performance for the parallel port and requires spe-
cial hardware logic. ECP ports use both an IRQ and
a DMA channel. See also IEEE 1284.
edge connector The part of a circuit board con-
taining a series of printed contacts that is inserted
into an expansion slot or a connector.
EDO (extended data out) RAM A type of
RAM chip that enables a timing overlap between
successive accesses, thus improving memory
cycle time.
EEB Entry-Level Electronics Bay is a specification
for pedestal servers developed by SSI. See also Server
System Infrastructure (SSI).
EEPROM (electrically erasable programma-
ble read-only memory) A type of nonvolatile
memory chip used to store semipermanent infor-
mation in a computer, such as the BIOS. An EEP-
ROM can be erased and reprogrammed directly in
the host system without special equipment. This is
used so manufacturers can upgrade the ROM code
in a system by supplying a special program that
erases and reprograms the EEPROM chip with the
new code. Also called flash ROM.
EGA (enhanced graphics adapter) A type of
PC video display adapter first introduced by IBM
on September 10, 1984, that supports text and
graphics. Text is supported at a maximum resolu-
tion of 80×25 characters in 16 colors with a charac-
ter box of 8×14 pixels. Graphics are supported at a
maximum resolution of 640×350 pixels in 16 (from
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