th3_" are
`Fully
`technologies, _ terms and a
`
`

`
`'I.:.:3"
`
`;'a'|lo_ca_’_tlon E
`
`eral pointers address the same chunk of storage, the pro-
`gram may free the storage using one of the pointers but
`then attempt to use another one (an alias), which would no
`longer be pointing to the desired data. This bug is avoid-
`able by the use of allocation strategies that never use more
`than one copy of a pointer to allocated core memory, or by
`the use of higher-level languages, such as LISP, which
`employ a garbage collection feature. Also Called.‘ stale
`pointer bug. See also alias, dynamic allocation, garbage
`collection.
`
`align vb. 1. in an application such as a word processor, to
`position lines of type relative to some point, such as the
`page margin. The most common types of alignment are
`left- and right-aligned and centered. See the illustration.
`2. To adjust some device to position it within specified tol-
`erances, such as the readlwrite head relative to a track on a
`disk. 3. In data handling, to store multiple-byte data units
`so that the respective bytes fall in corresponding locations
`of memory.
`‘
`
`Left
`M
`aligned
`to the
`left
`edge
`
`
`
`Right
`aligned
`to the
`right;
`
`edge
`
`Center
`centered
`arounda
`midpoint
`
`Decimal
`' ;.999
`:l.0;99
`:l.00;999
`10f.999
`
`'
`
`Align.
`
`alignment :1. The arrangement of objects in fixed or pre-
`determined positions, rows, or columns. For example, the
`Macintosh Finder can do automatic alignment of icons in
`a folder or on the desktop.
`
`Allegro 7:. Ported to a number of operating systems, Alle-
`gro is a freeware library of functions for use in program-
`ming computer games and graphics programs. It is written
`for the DJGPP compiler in a mixture of C and assembly
`language. The most recent release version is 4.0.0. See
`also assembly language, DJGPP.
`
`allocate vb. To reserve a resource, such as sufficient
`memory, for use by a program. Compare deallocate.
`
`allocation in. In operating systems, the process of reserv-
`ing memory for use by a program.
`
`
`
`
`
`Aux
`
`lso allows for stor-
`
`xture maps in sys-
`for large amounts
`uns at 66 MHz——
`upport data transfer
`[10ca1bu5_
`
`-
`Of Ipdpagkiiguthem
`stan at .
`thentication infor-
`
`data, which allows
`t allowed. See also
`
`:5 audio files in the
`
`: and Silicon Graph-
`
`sed on Apple and
`1F stores waveform
`also waveform.
`
`Instant Messenger.
`'ovided for free by
`, instant messages
`1_1S1n1iIt1I:Z}:‘IM soft"
`smg
`X91355‘
`iging. Compare
`Messenger.
`_
`,
`ion introduced by
`ass network and
`._ Card_equ§pped
`of an AirPort base
`the IEEE 802.11
`lustry standard and
`ad equipment.
`[her and decrypt
`etworks. Airsnort
`
`Jllects packets of
`2a, AirSnort is able
`the transmission.
`aws in the Wired
`
`lee also password
`
`tive Executive. A
`developed and
`:stations and PCs.
`
`[arm n. A visual or auditory signal from a computer
`' mg the user to an error or a hazardous situation.
`:2. See load balancing.
`,
`,
`,
`.
`‘git rt. 1. In many operating systems Wllll GUIs (graphi-
`agar interfaces), an audible or visual alarm that signals
`'1-for or represents a warning of some sort. See also
`
`ox. 2. In programming, an asynchronous notifica-
`-sent by one thread to another. The alert interrupts the
`I -‘plefll thread at defined points in its execution and
`uses it to execute an asynchronous procedure call. See
`
`' synchronous procedure call, thread (definition l).
`rt. box n. An on-screen box in a GUI (graphical user
`terrace) that is used to deliver a message or warning.
`in3 cu.,_.“.1.c:on 3>¢
`
`rter service in. A service used by the server and other
`mu’ es to notify selected users and computers of adrninis-
`ve alerts that occur on a computer. The Alerter service
`quires the Messenger service. See also administrative
`"“ens,-Messenger service, service.
`HOL n. Acronym for Algorithmic Language. The first
`tr-uctured procedural programming language, developed
`the Late 19505 and once widely used in Europe.
`oiithm n. A finite sequence of steps for solving a logi-
`th
`tical
`roblem or erforming a task.
`of ma _mm
`P
`P
`_
`orithmlc language n. A programming language, such
`Ada, Basic, C, or Pascal, that uses algorithms for prob-
`Solving.
`-I
`'
`lgorlthmio Language rt. See ALGOL.
`has n. 1. An alternative label for some object, such as a
`le or data collection. 2. A name used to direct e-mail
`"cssages to a person or group of people on a network.
`'
`false signal that results from the digitization of an
`g audio sample.
`sing n. In computer graphics, the jagged appearance
`ifcurves or’ diagonal lines on a display screen, which is
`
`sad by low screen resolution. See the illustration.
`
`.
`
`_ asing. The lower resolution of the image on the right
`" eals the aliasing effect.
`
`.l.i?l5ing bug n. A class of subtle programming errors that
`i_1_I_1 arise in code that performs dynamic allocation. If sev-
`
`

`
`
`
`medium“ n. A substance in which signals can be trans
`mitted, such as a wire or fiber-optic cable. See media . ‘
`medium model it. A memory model of the Intel 80x35
`processor family. The medium model allows only 54 kn[p
`bytes for data but generally up to 1 megabyte for code 58
`also memory model.
`'
`E
`medium-scale integration n. A concentration of cirmm
`elements in the hundreds on a single chip. Acronym _- Ms!
`See also integrated circuit.
`
`meg it. See megabyte.
`rnega- prefix One million (105). In computing, which is
`based on the binary (base-2) numbering system, mega. has
`a literal value of 1,048,576, which is the power of 2 (210)
`closest to one million. Abbreviation: M.
`megabit n. Usually 1,048,576 bits (239); sometimes -m,E,_
`preted as 1 million bits. Abbreviation: Mb, Mbit.
`e n. Usually 1,048,576 bytes £22“); sometimes
`megabyt
`interpreted as 1 million bytes. Abbreviation: MB.
`megacycie n. A term for 1 million cycles—usually used
`llion cycles per second. Abbreviation: MC,
`to mean 1 mi
`See also megahertz.
`
` ' Mell:s§,a‘:=l
`
`
`''\‘9'J&€aX"€$e9V:e\§‘;€t§I5i9.6?».St§1x\wzl_\.ri:..:«.m<«'s4.:-.»l»se_l.-,.»,-rm;-,,,,g,.,,,
`
`
`.
`
`'5
`i
`|
`I
`
`megaflops it. See MFLOPS.
`megahertz n. A measure of frequency equivalent to l
`million cycles per second. Abbreviation: Ml-lz.
`megapel display n. See rnegapixel display.
`megapixel adj. A reference to image resolution of one
`million pixels or more. The term is used in reference to
`.
`.
`.
`devices such as digital cameras, scanners, and computer
`monitors and display adapters.
`ay capable of dis—
`megapixel display :1. A video displ
`playing at least 1 million pixels. For example, a video dis-
`play with a screen size of 1024 horizontal pixels and 1024
`vertical pixels is a rnegapixel display. Also
`called.‘ megapel display.
`Melissa n. A macro virus that affects Word files in
`Microsoft Office 97 and Office 2000 and first appeared in
`the spring of 1999. Melissa is delivered asan attachment to
`' an e-mail with the subject line “An Important Message
`From <user name>," a message beginning “Here is that
`,” or both. When the attachment
`document you asked for. . .
`is opened, the virus propagates (if Microsoft Outlook is
`installed) by sendingitselfto the first 50 e—mail addresses in
`On the infected machine‘
`the user's Outlook address book.
`
`; .mechatronic's I‘
`
`"
`
`‘Z 1'
`
`'
`
`I
`
`
`
`permit an electric current
`surfaces. Because the markings
`hes that ride on the surface
`to flow,
`a set of conductive brus
`detect these conductive
`of the conductive wheels can
`n the mouse translate these
`markings. The electronics i
`nto mouse-movement infor-
`electrical movement signals i
`the computer. See also mouse,
`mation that can be used by
`mouse, optomechanical
`trackball. Compare optical
`IIIOUSB.
`
`from the words mechan-
`mechatronics n. A term derived
`field of engineering that
`ical and electronics to describe :1
`electronic engineering
`applies mechanical, electrical, and
`manufacture. A relatively
`concepts to product design and
`able to products in
`new discipline, mechatronics is applic
`factoring, and
`medicine, robotics, manu
`fields as diverse as
`consumer electronics.
`such as paper, disk, and
`media n. The physical material,
`tape, used for storing computer-based information. Media
`is plural; medium is singular.
`Media Access control n. See MAC.
`ntrol Interface :1. See MCI (definition 1).
`sion n. Transferring data from one sto
`-media conver
`from disk to tape.
`medium to another—-—for example,
`at removes or obliterates data
`media eraser n. Adevice th
`olesale basis, usually by
`from a storage medium on a wh
`(such as zeros) over it. See also
`writing meaningless data
`bulk eraser.
`
`rage
`
`
`
`ce used with local area networks
`media filter n. 1. A devi
`two different types of
`(LANS) as an adapter between
`45 connector might be used
`media. For example, an R1-
`hielded twisted pair (UTP)
`between coaxial cable and uns
`ar in function to transceivers.
`cables. Media filters are simil
`LANs, manufacturers often
`As with many components to
`products, so a LAN
`choose different names for similar
`ch media filters are required
`expert is needed to decide whi
`coaxial cable, connector
`for a particular LAN. See also
`UTP. 2. A device added
`(definition 1), LAN, transceiver-,
`filter out elelttronic noise from the
`'diafilter mightbe added
`to data networks to
`31 Cabling 30 l3T‘5"'31'1l3
`environment. For example, a me
`to an Ethernet network based on coaxi
`by nearby electronic equin
`(definition 1}
`data loss from interference
`ment. See also coaxial cable, Ethernet
`e of audio or
`media stream n. A continuous sequenc
`audio-and—video through a network.
`g to the middle part of a range
`rnediumi adj. Of or relatin
`of possible values.