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E1
- Four-wire digital
line "trunk" that can carry 2.048 Mbps.
Easter
egg - Term used for
special hidden code within an application that will only be ran if a
special procedure is ran such as holding down shift while clicking on an
icon in the program.
EBCDIC
- Refer to extended
binary coded decimal interchange code.
Echo
- Echo can mean
several things with communications and computers, however generally
follow the idea of sound or data being repeated to the sender. Can be
used with networks when a message is sent over the network the message /
information can be echoed back to the host computer to insure that it is
received correctly.
Echo
check - Precise use of
an echo in communications to ensure data is transmitted completely and
correctly.
Echoplex-
Type of visual echo check. When you type something on-screen to send to
another computer via modem, it is echoed back to your screen so the
message can be visually checked for inconsistencies by the user.
Echo
suppressor - Device
used to eliminate the echo heard on telephone lines. The echo suppressor
switches back and forth to allow the part currently speaking to send a
strong signal to the listener without hearing an echo of his own voice.
During full-duplex modem communication, the echo suppressor must be
switched off to allow the tow modems to exchange data at the same time.
ECP
- Refer to extended
capabilities port.
Edge
connector - Found
along one edge of an expansion card, edge connectors are made of lines or
stripes of metal that fit into an expansion slot inside a computer or a
ribbon cable connector.
EDI
- Refer to electronic
data interchange.
Edit
mode - Mode that
allows the modification of files.
Editor
- Also can be referred
to as a text editor, a type of program that lets you create and
manipulate text files. There are several kinds of editors. Regular,
full-screen editors lets you edit the text you see on-screen by
navigating the file with the cursor or arrow keys.
EDLIN
- Line editor used in
older DOS versions (older then DOS 5.0). Allows the editing of files
however only one at a time and can be very tedious in editing files that
have several lines.
EDO
- Technology of memory
used with newer motherboards supporting SIMM. On a computer that supports
EDO memory allows a CPU to access memory 10 to 15 percent faster the
compatible Fast Page memory.
Edutainment
software - Software
generally for children that runs along the fine line between education
and entertainment.
EEPROM
- Refer to
electrically erasable programmable read-only memory.
EGA
- Refer to Enhanced
graphics adapter.
EIA
- Refer to Electronic
Industries Association.
EIDE
- Refer to enhanced
integrated drive electronics.
EISA
- Refer to extended
Industry Standard Architecture.
Electronically
erasable programmable read-only memory (EEPROM) -
Form of EPROM that can be erased and reprogrammed with an electrical
process. This type of memory remembers data when the power is turned off,
and an electrical charge is needed for reprogramming. EEPROM is often
used to store a computer's BIOS. Generally, you will need a special PROM
programming device to change any data in EEPROM.
Electroluminescent
display (ELD) - First
flat screen with a wide angle that was used in portable computers, this
thin type of display uses electrical currents to give off light and
create on-screen images. A layer of phosphor is sandwiched between two
grids of horizontal and vertical electrodes. Where the electrodes
crisscross, pixels can be lit by passing a current through the
corresponding electrodes. These pixels , or tiny picture elements, then
combine to create the on-screen image.
Electromagnet
- Device that creates
a magnetic field by using an electric current. In computers,
electromagnets can be found on the read / write heads of disk drives.
Electromagnets are composed of wire coiled around an iron core.
Electromagnetic
spectrum - The range
of frequencies displayed by electromagnetic radiation visible light is a
form of electromagnetic radiation, as well as such familiar emissions as
X-rays, microwaves, and radio signals.
Electromotive
Force (EMF) - Another
name for difference of potential.
Electron
gun - Component used
in televisions and computer monitors that produce and manipulate the
electron beam that creates images in cathode-ray tube (CRT) displays.
Electronic
data interchange (EDI) -
Standards specifying how computerized business communications, such as
orders and invoices, should be formatted. EDI is supposed to eliminate
paperwork and speed up processes by making sure business and customer
computers can understand the data they send each other.
Electronic
Industries Association (EIA) - Group
which defines electronic standards in the U.S.
Electronic
mail (E-mail) - Text
messages and or files, images, and more sent through a network to a
specified individual or group.
Electronic
Numerical Integrator And Calculator (ENIAC) -Completed in 1946 at the University of Pennsylvania, it took about
1,800 square feet and used about 18,000 vacuum tubes, weighing almost 50
tons. First developed to help with the war effort the computer was
designed to calculate trajectories for new artillery being used against
German forces. However ENIAC was not completed until the end of the war .
The ENIAC wowed the world when it debuted, counting to 5,000 in one-fifth
of a second, although it probably has less computing power than some of
today's calculator's Although debated whether the ENIAC was the first
real real electronic computer, it has often been touted as such. The
ENIAC is now being displayed at the Smithsonian Institution in Washington
D.C.
Electronic
office - Term
described largely unrealized vision of the paperless office, where
electronic versions of documents stored in computers completely supplant
paper versions stored in file cabinets and in pies on desks.
Electronic
publishing - Type of
publishing in which the entire process, including the end result, is
electronic. Usually such publishing's are published on diskettes,
CD-ROM's, and through the Internet.
Electronic
white board - Computer
hardware and software that lets users of different PCs simultaneously
view and annotate a document or image. The electronic version usually
resembles an actual white board that users can draw on with a styles or
marker.
Electron
tube - Also known as a
vacuum tube, a glass tube that holds electrical changes within a vacuum
and is capable of turning on and off or amplifying electrical signals.
These tubes were used in the first computers for digital processing, but
have been replaced by transistors in most computers today.
Electrophotography
- Technology combining
elements of photography with electricity to reproduce images in some
printers and photocopiers. Negative image is created on a drum that is
electostatically charged. Where the light (from sources such as laser or
light-emitting diodes) comes though, the drum carries no charge. Powdery
toner sticks to the charged areas of the drum, and then is transferred to
the paper, where it adheres due to pressure and heat.
Electrostatic
- An electric charge
that doesn't flow through a medium but remains in one place. An
electrostatic charge likely is responsible for sticking all that dust on
your computer screen, and is also used in electrophotic printers to hold
toner particles on a drum.
Elite
- Typeface that can
fit 12 characters in one inches with each character the same width as
another.
ELIZA
- Written by Dr.
Joseph Weizenbaum as a joke, ELIZA was a famous psychotherapy computer
program designed to carry on a conversation with users by simply
repeating statements back as questions, picking out specific keywords
from previous comments made by the user.
Elf
emission - Refer to
extremely low frequency emissions.
E-mail
- Refer to electronic
mail.
Em
- Typography unit of
measure. In many fonts, it equals the width of a capital M.
Em
dash - A punctuation
mark that signifies a change of thought or explains an idea further.
Because most keyboards lack a key for the em dash (-), it must usually be
created with a special key combination specific to the program being
used.
Embedded
command - When you
embed a command within the text of a document, you insert it in a
specific place to affect the text there. For instance, you might use
embedded commands within a word processor to tell the program where you
want the text bolder, in italics, or in another font.
Embedded
object - Copy of an
object or file pasted into another file. For instance, if you want to
incorporate a small spreadsheet created with spreadsheet software into a
word processor.
EMF
- Refer to
Electromotive Force
Emm386.exe
- Executable file that
runs the expanded memory manager in Intel 80386-based and higher
computers. It uses extended memory to act as expanded memory, lets you
load programs into upper memory, and must first be activated by adding
several lines into the config.sys.
EMS
- Refer to expanded
memory specification.
EM
space - Represents a
space between letters or words that is the width of the point size. Named
after the em unit of measurement in typography, the em space is equal in
width of a capital M.
Emotions
- Can also be referred to as smile's and short for emotion icons, letters
or symbols used on the keyboard to represent what you are feeling such as
a :-) when your head is turned to the left represents a smiley.
Emulator
- Device, in the form of hardware or software that allows a computer or
other device to act as if it were something else. For example you may
want to use software designed for an IBM or compatible computer to work
on a Macintosh or vise versa.
Encapsulated
PostScript (EPS) -
Graphics file format that includes PostScript commands, which tell a
PostScript printer how the file should be printed. Instructions were
usually included in a .EPS file extension. For more file extensions refer
to our Extension Page.
Encode
- To change something
into a programming code. For instance, changing a letter into the binary
code for that letter, or changing an analog sound into a digital file.
Encrypt
- The act of encoding
a file for the purpose of preventing others from gaining access to its
contents. An encrypted file appears as a string of gibberish. In order to
read or use the file, it must be decrypted. Files are usually encrypted
using encryption programs. In most cases only users with the correct
password are able to use the encryption program to make the file readable
again.
En
dash - A dash smaller
than an em dash but usually longer than a regular hyphen; often used in
place of the word "to" such as 10-5 p.m.
Endless
loop - Also known as
an infinite loop; a continuous repetition of a program segment. For
example, in a BASIC program, an endless loop can be created by using the
GOTO statement going to another segment in the program referring back to
the original GOTO.
End
key - A key found on
most computer keyboards (indicated by the word End) that moves the cursor
to the end of the line, paragraph, page, screen, or document, depending
upon the program and specific key combination used.
End-of-file
(EOF) - A code placed
by a computer after a file's last byte of data. EOF marks are helpful in
data transmission and storage. Files are stored in blocks, and the end
marker helps the computer know it has allocated enough space to store the
file.
End-of-line
(EOL) - A code or mark
a user or computer may place at the end of a line of text to indicate the
end of that line.
End-of-message
(EOM) - In
communications, this code or mark is used to signal to the receiving
computer that the full message has been transmitted.
End-of-Text
(ETX) - In
communications, a code or mark used to signal to the receiving computer
that all of a text file has been transmitted. Because there may be some
other transmission checking codes that follow to check that everything
was sent correctly, users shouldn't assume that the ETX code means the
transmission is complete.
End
user - The individual
person who uses hardware or software programmed or designed by another.
Energy
Star - An
environmental Protection Agency (EPA) program to encourage PC's and
peripherals that use less energy. For a computer, printer, or monitor to
carry an Energy Star label, it must meet certain requirements. First, a
device must be able to sense when it has been left inactive for a
specific amount of time. Once the device has decided it has been left
inactive, then it must be able to power down to a mode in which it
consumes no more than 30 watts of energy. Monitors in this state, for
example, will go blank. No data is lost when computer components enter a
low-power mode, but it may take a few seconds for the computer to
"wake up" once again. Usually moving the mouse or pressing a
key on the keyboard would get the computer out of this mode.
Engine
- The part of an
application that actually controls the manipulation of data. Don't
confuse the engine with the interface or with things such as device
drivers, which help the software work with components within the
computer. Engine also may refer to a special processor used inside the
computer to speed up graphics and printing.
Enhanced
graphics adapter (EGA) - A
video card manufactured by IBM in 1984 that has higher resolution, more
colors (16 from a palette of 64), and obeys the computer much faster than
the older video cards, such as color / graphics adapter (CGA). EGA cards
can produce a resolution of 640 horizontal pixels by 350 vertical pixels,
which is not quite as capable as VGA with 640 x 480 resolution but better
than the color / graphics adapter card with a 320 x 200 resolution.
Enhanced
Integrated Drive Electronics (EIDE) - Also known as Fast AT Attachment (Fast ATA), this is an updated version
of the Integrated Drive Electronics (IDE) storage interface that works
with hard drives and CD-ROM drives. It can transfer data to and from the
drive three to four times faster than the IDE standard (transferring data
between 11MB and 16.6MB per second), and can support devices that store
more data (up to about 8GB) than IDE drives.
Enhanced
keyboard - The type of
keyboard that comes with almost all PCs sold today. It includes 101 or
102 keys. The biggest difference between enhanced keyboards and earlier
versions is that the enhanced keyboard has 12 function keys running
across the top of the keyboard, instead of 10 that run down the left
side. Other changes include the addition of extra CTRL, keys, ALT keys,
and cursor arrow keys between the letter keys and numeric keypad on the
right side.
Enhanced
mode - Most often, you
will see this term used in the phrase 386-enhanced mode. This is
Microsoft Windows mode used by 386, 486, and Pentium computers to take
advantage of virtual memory, allowing computers to run more than one
program at a time so the programs don't interfere with each other's
allocation of memory. It's the standard mode used by Windows for
Workgroups and can be run by Windows 3.1 requiring at least 2MB of RAM.
It also allows DOS applications to be run within a window in Windows.
Enhanced
Parallel port (EPP) - A
type of parallel port that looks like any parallel port with 25 pins and
the same shape. However, it can work about twice as fast as the original
parallel ports, and can transfer data back and forth between a peripheral
and a computer at the same time. This type of parallel port was developed
by Intel, Xircom, and Zenith, at the same type the extended capabilities
port (ECP) was being developed by Microsoft and Hewlett-Packard. EPP is a
popular type of port for many portable computers.
Enhanced
serial interface (ESI) - A
standard introduced by Hayes Microcomputer Products for the serial port,
which is commonly used to connect a modem or other such device to the
computer. Along with an enhanced serial port, the connection should allow
for easy data transfer over phone lines up to speeds of 38.4 Kilobits per
second.
Enhanced
Small Devices Interface (ESDI) - A standard interface popular in the 1980s that allowed hard drives, tape
drives, and diskette drives to work with a computer. It could transfer
data at about 1MB to 3MB a second. However, ESDI has been outdated by
storage interfaces such as IDE, EIDE, and SCSI.
ENIAC
- Refer to Electronic
Numerical Integator and Calculator.
Enquiry
Character - A code
that some communications devices will send to devices with which they are
communicating in order to request a response for identification or to
make a connection.
En
space - A space that
takes up only half a point size, named after the typography unit of
measurement en.
Enterprise-Wide
network - A network
that connects computers throughout an organization including computers in
different buildings or cities. This includes the computers, servers,
gateways, and all the components that make up the network.
Entry
- Most often, an entry
refers to a word, phrase, number, or other information that you might
enter into a spreadsheet or database cell or field. Although what you
enter in one field may be more than one word or number, it's considered a
whole entry.
computer
can read from but not store information to. However, they are erasable
when exposed to ultraviolet light and can be reprogrammed. Hardware
manufactures like to use EPROM when they need memory that can be changed.
Erase
head - A type drive
component near the read / write head that erases information on the tape
by demagnetizing it.
Ergonomics
- The study or science
of how people interact with their work areas. The goal is to keep things
as comfortable and effective as possible. Ergonomics can help to
determine the proper setup of a chair, desk, or monitor height.
Error
Control - Various
techniques that check the reliability of characters (parity) or blocks of
data. V.42 and MNP error control protocols use error detection (CRC) and
retransmission of flawed frames (ARQ).
Error
rate - A measure of a
communication or network connection's reliability. Specifically, the
number of units with errors compared to the total number of units
transmitted.
ESDI
- Refer to Enhanced
Small Devices Interface.
Ethernet
- A widely used
local-area network (LAN) protocol created by Xerox in 1976. Later it was
rewritten by Xerox with Digital Equipment Corp. and Intel. Ethernet is
the original carrier sense multiple access / collision avoidance (CSMA/CD)
LAN that lets PCs listen for pauses before they "speak." Early
Ethernet models used a sort of bus architecture with coaxial (television)
cable. A new implementation called 10Base-T, lets Ethernet networks use
wiring similar to that used in telephone systems. While Ethernet is one
of the more popular LAN systems today, it is the middle-of-the-line in
terms of manageability, cost, and speed.
Exa
- Used as a prefix
before a unit of measurement this terms equals about one quintillion, or
10th to the 18th power. To be more exact, exa- actually equals
1,152,921,504,606,846,976, or 2 to the 60th power.
Exabyte(EB)
- Approximately one
quintillion bytes or about, 1,000,000,000,000,000,000 bytes.
Exception
- In communications
anything that happens that is out of the ordinary. In programming, an
exception is something that happens, maybe caused by an error or a
variation, to make the microprocessor put what it is doing on hold to
perform another set of instructions first.
.EXE
- A file extension on
a PC computer that indicates the file is an executable file.
Executable
file - A file that can
be executed, or run, as opposed to data files, which are simple
collections of data that can be used by executable files.
Execute
- To run a file or
command, or to complete and action.
Exit
- A command or option
that will get you out of and close a program. It may require a special
keystroke or key combination in a DOS program, or require you to select
the Exit option from the File menu in a Windows program.
Expand
- To change the view
of a hierarchical listing so that the entire branch of the directory is
displayed. For example, in the Windows File Manager, a listing of files
could be expanded so that all the folders and files are showing, instead
of just the folders.
Expanded
memory - The amount of
memory past the first 640KB of memory (which is known as conventional, or
base, memory), up to 1MB. Also known as the upper memory area, this area
is often used to hold programs and device drivers that might otherwise
use up conventional memory space. To operate properly in DOS, expanded
memory requires a special manager application or an expanded memory
manager. See our RAM diagram for
an example of what all the sections of memory look like.
Expanded
memory manager (EMM) - A
device driver that lets DOS based computers use expanded memory. It
requires additional hardware, in the form of an expansion memory board,
to use the expanded memory manager in 8088-, 8086, and 286 based systems,
although 386-based systems and higher simply require the memory managers
to tun extended memory into expanded memory.
Expanded
memory specification (EMS) - The
specification that lets DOS systems use more than 1MB of RAM, swapping
pages out of expanded memory into an area the operating system can
access. Expanded memory is "expanded" past the first 640KB of
memory (which is known as conventional, or base, memory), up to 1MB. Also
known as the upper memory area, this area is often used to hold programs
and device drivers that might otherwise use up conventional memory space.
Expansion
- Adding extra
hardware to your computer, such as a better video card, a CD-ROM drive,
or a sound card, to give your PC added capability. Usually this requires
plugging an external devices into a port on the computer, or installing a
circuit card into a slot within the computer.
Expansion
card - An add-on
electronic circuit board that gives a computer new abilities. Expansion
cards can be used to connect devices such as modems, fax / modems, sound
cards, graphics cards. These cards fit into expansion slots on the riser
board or motherboard inside the computer's case. Portable computers use a
special slot on the back or on the side called a PC card or PCMCIA slot.
Expansion
slot - A slot or
socket inside a computer that allows the installation of add-on expansion
cards. Such cards give the computer new abilities or otherwise improve
operations. The slot is actually an outlet on the motherboard that
provides a direct connection between the computer bus, or main data
pathway, and the expansion card. Expansion cards must be made to fit the
various types of expansion slots. The main types are ISA, EISA, VESA, PCI,
and AGP.
Expert
system - Considered a
form of artificial intelligence; this is an application that makes
decisions by using facts, rules, and a reasoning ability called an
inference engine. The facts are supplied by human experts in a particular
field. Common categories include medical, investments, automobile
routing, insurance, equipment repairs, and science. Users query, or ask a
question, of the expert system. It then comes up with an answer according
to the facts and rules with which it has been programmed, and explains
its results. However, these results may sometimes be a little skewed by a
computer's "black-or-white" approach to reasoning. Also called
rule-based system.
Explode
- To restore
compressed data back to its original form. Also see unzip.
Export
- To transfer data
from one computer to another or one application to another. Before a file
is exported, the computer or program generally must change the file to a
format the other computer or program can use. Many desktop publishing
word processing, and graphics programs will include an Export command
that allows the user to select a format for the exported file.
Expression
- A combination of
symbols and letters that represents an operation of value in computer
programming. Expressions may be strings of characters and symbols, such
as "Jane Dow," or numeric phrases, such as 2 + 3. You also
might use an expression of symbols and letters in a database to search
for data or in a spreadsheet to perform calculations. An expression
differs from an action statement, which performs an action instead of
designating a value.
Extended
ASCII - While the
regular American Standard Code for Information Interchange (ASCII) uses
seven bits of code characters (equaling 128 characters), extended ASCII
uses eight bits, adding another 128 characters. The original ASCII
defines the codes for the average letters and numbers used by computers.
Extended ASCII defined extra characters, such as a special symbols,
foreign language letters, or drawing characters.
Extended
Binary Coded Decimal Interchange Code (EBCDIC) - A
coding method used by larger computer systems to present letters,
numbers, and other symbols in a binary language the computer can
understand. Codes can be made of eight bits of information, allowing for
256 possible character codes. EDCDIC was first developed by IBM. The
coding used by most PCs and microcomputers, however, is ASCII.
Extended
capabilities port (ECP) - A
parallel port standard developed by Microsoft Corp. and Hewlett-Packard
for high-speed port that allows communications back and forth between the
computer and the peripheral. Another, similar type of parallel port is
the enhanced parallel port (EPP). The parallel port types don't differ in
size, they just differ in how they operate.
Extended
graphics array (XGA) - IBM's
upgrade to the VGA video card. With a resolution of 1,024 horizontal
pixels by 768 Vertical pixels and 256 colors it is proprietary standard -
meaning it will only work on IBM systems.
Extended
Industry Standard Architecture (EISA) - The standard for an IBM and IBM-compatible computer data bus that can
transfer 32 bits of data at a time. The architecture is used by some
Intel 80386-, 80486-, and Pentium-based computers and was designed in
1988 by a group of IBM competitors as an alternative to IBM's bus at the
time, MCA (Micro Channel Architecture). EISA is backward compatible with
an older 16-bit bus standard called ISA (Industry Standard Architecture).
Extended
memory - The name for
all memory above the first megabyte. Extended memory is not usually
available to DOS programs under normal circumstances because most DOS
programs are formatted to use conventional memory. It is available to
Microsoft Windows programs (when the computer is operating in a protected
or virtual real mode), and can be used by RAM disks or disk caches. The
expanded memory manager can allow extended memory to act as expanded
memory.
Extended
memory specification (XMS) - Determines
how a 286-based or higher computer can use extended memory and the high
memory area in DOS, requiring the use of the expanded memory manager (EMM)
driver. Extended memory extends the operation system's reach beyond the
first megabyte of memory , while the high memory area is the first 64KB
of that extended memory. It was originally developed by Microsoft Corp.,
Intel Corp., AST Research, and Lotus Development Corp.
Extended
Technology (XT) - The
full name for the first IBM PC that contained a hard disk. It was
introduced in 1983.
Extended
video graphics array (Extended VGA) - Refer to Super VGA.
Extension.
- Refer to file
extension.
External
command - A DOS
command not included in Command.com, which is the DOS file that teaches
the computer how to respond to most commands. A command is excluded from
the Command.com because its definition is too length. An good example of
an external command would be FDISK.COM.
External
Function (XFCN) - A
function or task created by the user or developer that is not available
in the original program.
External
icons - User-created
or non Windows icons.
External
LAN adapter - An
external unit, usually in the form of a PC card, that plugs into a PC
card socket or laptop computer in order for it to connect to a local-area
network. The only requirement is that the adapter is compatible with the
network's topology and that the laptop has the proper network software
and operating system on it.
External
modem - A modem that
does not reside inside the computer's case but is in a box of its own
external of the computer. External modems generally hook up to the Serial
port and are usually more expensive then Internal modems, but can be
easier to install.
External
storage - Any type of
computer storage that isn't included in the computer's main memory. Any
hard disk drive, diskette, tape drive, or other similar device would be
an external storage unit.
Extremely low frequency emissions (ELF emissions) - One of the magnetic emissions given off by
computer monitors. It is unknown if such emissions are harmful to humans,
who encounter tham near many common appliances, such as hair dryers. To
regulate such emissions, the Swedish government created the MRP II
standard for computer monitors. Monitors meeting this standard give off
very low ELF emissions.
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