~E~
erase head ~ ezine
A/B Switch box ~ America On-line AMI BIOS ~ Arithmetic Operation ARP ~ AVI Backbone ~ Bit Image Bit Map ~ Boot Disk Boot Drive ~ Bytes Per Inch C++ ~ Carrier Frequency carrier system ~ certification CGI ~ Chooser extension cipher ~ Clipper Chip clock ~ color color bits ~ communications satellite communications server ~ computer security CON ~ copy copy program ~ cycle time daemon ~ defragmentation demand paging ~ digitize DikuMUD ~ disk disk buffer ~ Document Style Semantics and Specification Language document window ~ dynamic Web page Easter egg ~ erase erase head ~ ezine F2F ~ finger2 firewall ~ font suitcase footer ~ FYI Game Control Adapter ~ GUI HAL ~ hot key1 hot key2 ~ Hz i486DX ~ internal modem internet ~ ISO 9660 ISO/OSI model ~ just-in-time K1 ~ knowledge base L1 cache ~ LU luggable computer ~ LZW compression MAC ~ MILNET mime ~ msec MTBF ~ MYOB named anchor ~ network drive Network File System ~ number crunching object ~ overwrite mode P5 ~ PC/XT keyboard PDA ~ pipeline processing piracy ~ preventive maintenance preview ~ pwd quasi-language ~ QWERTY keyboard R&D ~ registration marks Registry ~ RFI RF shielding ~ run-time library SAA ~ server error server push-pull ~ soft return software ~ style sheet stylus ~ System T1 ~ ToggleKeys token ~ typography UART ~ uupc V.120 ~ view2 viewer ~ VxD w3 ~ WinG WINS ~ WWW X.25 ~ X Windows Yahoo! ~ yotta- Z39.50 standard ~ Zulu time
erase head
n. The device in a magnetic tape machine that erases previously recorded information.
ergonomic keyboard
n. A keyboard designed to reduce the risk of wrist and hand injuries that result from prolonged use or repetitive movement. An ergonomic keyboard can include such features as alternative key layouts and palm rests. See also Dvorak keyboard, keyboard, Kinesis ergonomic keyboard.
ergonomics
n. The study of people (their physical characteristics and the ways they function) in relation to their working environment (the furnishings and machines they use). The goal of ergonomics is to incorporate comfort, efficiency, and safety into the design of keyboards, computer desks, chairs, and other items in the workplace.
error
n. A value or condition that is not consistent with the true, specified, or expected value or condition. In computers, an error results when an event does not occur as expected or when impossible or illegal maneuvers are attempted. In data communications, an error occurs when there is a discrepancy between the transmitted and received data. See also critical error, error message, error rate, error ratio, fatal error, hard error, inherent error, intermittent error, logic error, machine error, overflow error, parity error, propagated error, read error, recoverable error, syntax error, system error, write error. Compare fault.
error checking
n. A method for detecting discrepancies between transmitted and received data during file transfer.
error detection and correction
n. A method for discovering and resolving errors during file transfer. Some programs only detect errors; others detect and attempt to fix them.
error file
n. A file that records the time and type of data processing and transmission errors.
error handling
n. The process of dealing with errors (or exceptions) as they arise during the running of a program. Some programming languages, such as C++, Ada, and Eiffel, have features that aid in error handling. See also bug (definition 1).
error message
n. A message from the system or program indicating that an error requiring resolution has occurred.
escape code
n. A character or sequence of characters that indicates that a following character in a data stream is not to be processed in the ordinary way. In the C programming language, the escape code is the backslash \, which has several uses, as shown by the statement printf ("The backslash \"\\\" is the escape code.\n") ;. The last backslash, which is the next-to-last character in the string, indicates that the following n is not to be printed but that the sequence \n represents the newline character. By contrast, the backslashes before the quotation marks indicate that the latter are to be printed, rather than marking the end of one string and the beginning of another; similarly, the backslash before a backslash indicates that the second backslash is to be printed, rather than serving as an escape code. The resulting output is The backslash"\" is the escape code.
Escape key
n. A key on a computer keyboard that sends the escape (ESC) character to the computer. In many applications, the Escape key moves the user back one level in the menu structure or exits the program. See also Clear key.
escape sequence
n. A sequence of characters that usually begins with the ESC character (ASCII 27, hexadecimal 1B), which is followed by one or more additional characters. An escape sequence escapes from the normal sequence of characters (such as text) and issues an instruction or command to a device or program.
ESC character
n. One of the 32 control codes defined in the ASCII character set. It usually indicates the beginning of an escape sequence (a string of characters that give instructions to a device such as a printer). It is represented internally as character code 27 (hexadecimal 1B) Also called escape character.
ESDI
n. Acronym for Enhanced Small Device Interface. A device that allows disks to communicate with computers at high speeds. ESDI drives typically transfer data at about 10 megabits per second, but they are capable of doubling that speed.
ESP
n. See enhanced serial port.
ESP IEEE standard
n. Short for Encapsulating Security Payload IEEE standard. A standard for providing integrity and confidentiality to IP (Internet Protocol) datagrams. In some circumstances, it can also provide authentication to IP datagrams. See also authentication, datagram, IEEE, IP.
e-text
n. Short for electronic text. A book or other text-based work that is available on line in an electronic media format. An e-text can be read on line or downloaded to a user's computer for offline reading. See also ezine.
Ethernet
n. 1. An IEEE 802.3 standard for contention networks. Ethernet uses a bus or star topology and relies on the form of access known as Carrier Sense Multiple Access with Collision Detection (CSMA/CD) to regulate communication line traffic. Network nodes are linked by coaxial cable, by fiber-optic cable, or by twisted-pair wiring. Data is transmitted in variable-length frames containing delivery and control information and up to 1500 bytes of data. The Ethernet standard provides for baseband transmission at 10 megabits (10 million bits) per second. See also 10Base2, 10Base5, 10BaseF, 10BaseT, baseband, bus network, coaxial cable, contention, CSMA/CD, IEEE 802 standards, twisted-pair cable. 2. A widely used local area network system developed by Xerox in 1976, from which the IEEE 802.3 standard was developed.
Ethernet/802.3
n. The IEEE standard for 10- or 100-Mbps transmissions over an Ethernet network. Ethernet/802.3 defines both hardware and data packet construction specifications.
Eudora
n. An e-mail client program originally developed as freeware for Macintosh computers by Steve Dorner at the University of Illinois, now maintained in both freeware and commercial versions for both Macintosh and Windows by Qualcomm, Inc.
EULA
n. See End-User License Agreement.
evaluation
n. The determination, by a program, of the value of an expression or the action that a program statement specifies. Evaluation can take place at compile time or at run time.
exa-
prefix Abbreviated E. A prefix meaning one quintillion (1018). In computing, which is based on the binary (base-2) numbering system, exa- has a literal value of 1,152,921,504,606,846,976, which is the power of 2 (260) closest to one quintillion.
exabyte
n. Abbreviated EB. Roughly 1 quintillion bytes, or a billion billion bytes, or 1,152,921,504,606,846,976 bytes.
exception
n. In programming, a problem or change in conditions that causes the microprocessor to stop what it is doing and handle the situation in a separate routine. An exception is similar to an interrupt; both refer the microprocessor to a separate set of instructions. See also interrupt.
exception error 12
n. An error created in DOS environments caused by a stack overflow. This problem may be corrected by modifying the CONFIG.SYS file and editing the STACKS= entries.
executable1
adj. Of, pertaining to, or being a program file that can be run. Executable files have extensions such as .bat, .com, and .exe.
executable2
n. A program file that can be run, such as file0.bat, file1.exe, or file2.com.
executable program
n. A program that can be run. The term usually applies to a compiled program translated into machine code in a format that can be loaded into memory and run by a computer's processor. In interpreter languages, an executable program can be source code in the proper format. See also code (definition 1), compiler (definition 2), computer program, interpreter, source code.
execute
vb. To perform an instruction. In programming, execution implies loading the machine code of the program into memory and then performing the instructions.
exit
vb. In a program, to move from the called routine back to the calling routine. A routine can have more than one exit point, thus allowing termination based on various conditions.
expanded
adj. A font style that sets characters farther apart than the normal spacing. Compare condensed.
expanded memory
n. A type of memory, up to 8 MB, that can be added to IBM PCs. Its use is defined by the Expanded Memory Specification (EMS). Expanded memory is not accessible to programs in MS-DOS, so the Expanded Memory Manager (EMM) maps pages (blocks) of bytes from expanded memory into page frames in accessible memory areas. See also EEMS, EMS, Expanded Memory Manager, page frame.
Expanded Memory Manager
n. A driver that implements the software portion of the Expanded Memory Specification (EMS) to make expanded memory in IBM and compatible PCs accessible. See also EMS, expanded memory, extended memory. Acronym: EMM.
expansion
n. A way of increasing a computer's capabilities by adding hardware that performs tasks that are not part of the basic system. Expansion is usually achieved by plugging printed circuit boards (expansion boards) into openings (expansion slots) inside the computer. See also expansion board, expansion slot, open architecture (definition 2), PC Card, PCMCIA slot.
expansion board
n. A circuit board that is plugged into a computer's bus (main data transfer path) to add extra functions or resources to the computer. Typical expansion boards add memory, disk drive controllers, video support, parallel and serial ports, and internal modems. For laptops and other portable computers, expansion boards come in credit card-sized devices called PC Cards that plug into a slot in the side or back of the computer. Also called expansion board, extender board. See also expansion slot, PC Card, PCMCIA slot.
expansion slot
n. A socket in a computer, designed to hold expansion boards and connect them to the system bus (data pathway). Expansion slots are a means of adding or enhancing the computer's features and capabilities. In laptop and other portable computers, expansion slots come in the form of PCMCIA slots designed to accept PC Cards. See also expansion board, PC Card, PCMCIA slot.
expert system
n. An application program that makes decisions or solves problems in a particular field, such as finance or medicine, by using knowledge and analytical rules defined by experts in the field. It uses two components, a knowledge base and an inference engine, to form conclusions. Additional tools include user interfaces and explanation facilities, which enable the system to justify or explain its conclusions as well as allowing developers to run checks on the operating system. See also artificial intelligence, inference engine, intelligent database, knowledge base.
expiration date
n. The date on which a shareware, beta, or trial version of a program stops functioning, pending purchase of the full version or the entry of an access code.
Explorer
n. See Internet Explorer, Windows Explorer.
export
vb. To move information from one system or program to another. Files that consist only of text can be exported in ASCII (plain text format). For files with graphics, however, the receiving system or program must offer some support for the exported file's format. See also EPS, PICT, TIFF. Compare import.
extended ASCII
n. Any set of characters assigned to ASCII values between decimal 128 and 255 (hexadecimal 80 through FF). The specific characters assigned to the extended ASCII codes vary between computers and between programs, fonts, or graphics characters. Extended ASCII adds capability by allowing for 128 additional characters, such as accented letters, graphics characters, and special symbols. See also ASCII.
extended characters
n. Any of the 128 additional characters in the extended ASCII (8-bit) character set. These characters include those used in several foreign languages, such as accent marks, and special symbols used for creating pictures. See also extended ASCII.
extended memory
n. System memory beyond 1 megabyte in computers based on the Intel 8086 processors. This memory is accessible only when an 80386 or higher-level processor is operating in protected mode or in emulation on the 80286. To use extended memory, MS-DOS programs need the aid of software that temporarily places the processor into protected mode or by the use of features in the 80386 or higher-level processors to remap portions of extended memory into conventional memory. Programs running under Microsoft Windows, OS/2, and other operating systems that run on Intel processors and use the protected mode of the 80386 and higher-level processors can access all system memory in the same way. See also EMS, extended memory specification, protected mode.
extended memory specification
n. A specification developed by Lotus, Intel, Microsoft, and AST Research that defines a software interface allowing real-mode applications to use extended memory and areas of memory not managed by MS-DOS. Memory is managed by an installable device driver, the Expanded Memory Manager (EMM). The application must use the driver to access the additional memory. See also Expanded Memory Manager, extended memory. Acronym: XMS.
extended VGA
n. An enhanced set of Video Graphics Array (VGA) standards that is capable of displaying an image of from 800 × 600 pixels to 1600 × 1200 pixels and that can support a palette of up to 16.7 million (224) colors. This palette approaches the 19 million colors that a normal person can distinguish, so it is considered a digital standard for color realism that parallels analog television. Also called Super VGA, SVGA. See also analog-to-digital converter, CRT, VGA.
extension manager
n. On the Macintosh, a utility that allows the user to determine which extensions are loaded when the computer is turned on. See also extension (definition 4).
External Gateway Protocol
n. A protocol for distributing information regarding availability to the routers and gateways that interconnect networks. See also gateway, router. Acronym: EGP.
external hard disk
n. A free-standing hard disk with its own case and power supply, connected to the computer with a data cable and used mainly as a portable unit. See also hard disk.
external modem
n. A stand-alone modem that is connected via cable to a computer's serial port. See also internal modem.
extract
vb. 1. To remove or duplicate items from a larger group in a systematic manner. 2. In programming, to derive one set of characters from another by using a mask (pattern) that determines which characters to remove.
ezine
n. Short for electronic magazine. A digital production available on the Internet, a BBS, or other online service, often free of charge.
A/B Switch box ~ America On-line AMI BIOS ~ Arithmetic Operation ARP ~ AVI Backbone ~ Bit Image Bit Map ~ Boot Disk Boot Drive ~ Bytes Per Inch C++ ~ Carrier Frequency carrier system ~ certification CGI ~ Chooser extension cipher ~ Clipper Chip clock ~ color color bits ~ communications satellite communications server ~ computer security CON ~ copy copy program ~ cycle time daemon ~ defragmentation demand paging ~ digitize DikuMUD ~ disk disk buffer ~ Document Style Semantics and Specification Language document window ~ dynamic Web page Easter egg ~ erase erase head ~ ezine F2F ~ finger2 firewall ~ font suitcase footer ~ FYI Game Control Adapter ~ GUI HAL ~ hot key1 hot key2 ~ Hz i486DX ~ internal modem internet ~ ISO 9660 ISO/OSI model ~ just-in-time K1 ~ knowledge base L1 cache ~ LU luggable computer ~ LZW compression MAC ~ MILNET mime ~ msec MTBF ~ MYOB named anchor ~ network drive Network File System ~ number crunching object ~ overwrite mode P5 ~ PC/XT keyboard PDA ~ pipeline processing piracy ~ preventive maintenance preview ~ pwd quasi-language ~ QWERTY keyboard R&D ~ registration marks Registry ~ RFI RF shielding ~ run-time library SAA ~ server error server push-pull ~ soft return software ~ style sheet stylus ~ System T1 ~ ToggleKeys token ~ typography UART ~ uupc V.120 ~ view2 viewer ~ VxD w3 ~ WinG WINS ~ WWW X.25 ~ X Windows Yahoo! ~ yotta- Z39.50 standard ~ Zulu time