Dictionary of Computing - 5th Edition

magnetic memory

204

magnetic memory /m net kmem(ə)ri/ noun storage that uses a medium that can store data bits as magnetic field changes

magnetic polarity /m net k pəυl r ti/ noun a method of indicating if a point is a source or collector of magnetic flux patterns

magnetic recording /m net k rkɔ d ŋ/ noun the process of transferring an electrical signal onto a moving magnetic tape or disk by means of an magnetic field generated by a magnetic head magnetic screen /m net k skri n/ noun a metal screen to prevent stray magnetic fields affecting electronic components

magnetic storage /m net kstɔ r d'/ noun a method of storing information as magnetic changes on a sensitive disk, such as a floppy disk or hard disk magnetic strip /m net k str p/ noun a layer of magnetic material on the surface of a plastic card, used for recording data

magnetic stripe /m net k stra p/ noun a strip of magnetic material, containing information in coded form, on a plastic card such as a credit card

magnetic strip reader /m net kstr p ri də/ noun same as magnetic

card reader

magnetic tape /m net k te p/ noun a narrow length of thin plastic coated with a magnetic material used to store signals magnetically

COMMENT: Magnetic tape is available on spools of between 200 and 800 metres. The tape is magnetised by the read/write head. Tape is a storage medium that only allows serial access, that is, all the tape has to be read until the required location is found, as opposed to disk storage, which can be accessed randomly.

magnetic tape cartridge /mnet k te p kɑ tr d'/ noun a small box

containing a reel of magnetic tape and a pick up reel, used in a cassette player or tape drive

magnetic tape cassette /m net k te p kə set/ noun same as magnetic tape cartridge

magnetic tape encoder /m net k te p en kəυdə/ noun a device that direct-

ly writes data entered at a keyboard onto magnetic tape

magnetic tape reader /m net k te p ri də/ noun a machine that can read

signals stored on magnetic tape and convert them to an electrical form that can be understood by a computer

magnetic tape recorder /m net kte p r kɔ də/ noun a device with a mag-

netic head, motor and circuitry to allow electrical signals to be recorded onto or played back from a magnetic tape

magnetic tape transport /mnet k te p tr nspɔ t/ noun a computer-

controlled magnetic tape drive mechanism magnetic transfer /m net k

tr nsf / noun the copying of signals stored on one type of magnetic medium to

another

magnetise / m nə ta z/, magnetize verb to convert a material or object into a magnet

magneto-optical disc /m ni təυɒpt k(ə)l d sk/ noun an optical disc that

is used in a magneto-optical recording device

magneto-optical recording /mni təυ ɒpt k(ə)l r kɔ d ŋ/ noun a

method of recording that uses an optical disc covered with a thin layer of magnetic film that is heated by a laser. The particles are then polarised by a weak magnetic field. (NOTE: Magneto-optical discs have very high capacity, over 600Mb, and are re-writable.)

magnitude / m n tju d/ noun a level or strength of a signal or variable

mag tape / m te p/ noun same as magnetic tape (informal)

mail /me l/ noun electronic messages to and from users of a bulletin board or network

mail application programming interface / me l pl ke ʃ(ə)nprəυ r m ŋ ntəfe s/ noun full form

of MAPI

mailbox / me lbɒks/, mail box / me l bɒks/ noun an electronic storage space with an address in which a user’s incoming

messages are stored

mail-enabled /me l n e b(ə)ld/ adjective referring to an application that has access to an electronic mail system without leaving the application This word-proc- essor is mail-enabled – you can send messages to other users from within it.

mail exchange record / me l kstʃe nd' rekɔ d/ noun (in an electronic

mail system) information stored in the DNS, a database that helps locate a domain name on the Internet or a Unix net-

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maintain

work, that tells a mail system how to deliver a mail message to a particular domain

Mail sent to ‘smith&pcp.co.uk’ will be sent to the ‘pcp.co.uk’ server by the MX record, the local server then has to send the message to the user ‘smith’. Also called MX record

mail gateway / me l e twe / noun a software program, or a combination of server and software, that links two different electronic mail systems together so that mail messages can be transferred from one system to another. For example, if you are using Lotus cc:Mail as the electronic mail product within your company, you would need to fit a gateway function to allow messages to be sent to and received by users on the Internet. (NOTE: LAN e-mail systems normally use one of three main standards, MAPI, MHS or VIM, to send mail messages. If you are sending mail from a LAN e-mail system to the Internet the mail gateway needs to convert this standard to one of the Internet mail standards such as POP3 or SMTP before it can be delivered.)

mailing / me l ŋ/ noun the process of sending something using the post or e-mail

mailing list / me l ŋ l st/ noun (in electronic mail) list of the e-mail addresses of users who receive information on a regular basis from a company, a person or from other people on the list. An Internet mailing list allows any person whose name and address are on the list to send a message to the list, which will then automatically distribute a copy of this message to all the other people on the list.

mailmerge / me lm d'/ noun a wordprocessing program which allows a standard form letter to be printed out to a series of different names and addresses

‘Spreadsheet views for data and graphical forms for data entry have been added to the Q&A database, with the traditional reporting, mailmerge, and labels improved through Windows facilities.’ [Computing]

mail server /me l s və/ noun a computer that stores incoming mail and sends it to the correct user and stores outgoing mail and transfers it to the correct destination server on the Internet

mail transfer agent / me l tr nsfe d'ənt/ noun a software program that

manages the way electronic mail messages are transferred over a network. On computers running the Unix operating system and the Internet the ‘sendmail’ software is

the most popular mail transfer agent. Abbr

MTA

mail user agent / me l ju zəe d'ənt/ noun full form of MUA

main /me n/ adjective most important main body / me n bɒdi/ noun a set of

instructions that form the main part of a program and from which other subroutines

are called

main clock / me n klɒk/ noun a clock signal that synchronises all the compo-

nents in a system

main entry /me n entri/ noun an entry in a catalogue that contains the most important information about a particular doc-

ument

mainframe / me nfre m kəm pju tə/, mainframe computer / me nfre m kəm

pju tə/ noun a large-scale high-power computer system that can handle high-ca- pacity memory and backing storage devices as well as a number of operators simultaneously

mainframe access / me nfre mkses/ noun the process of using microcomputers to access a mainframe compu-

ter

main index /me n ndeks/ noun a general index that directs the user gradually to more specific index areas

main loop / me n lu p/ noun a series of instructions performed repeatedly that carry out the main action of a program. This loop is often used to wait for user input be-

fore processing the event.

main memory /me n mem(ə)ri/ noun a fast-access RAM whose locations can be directly and immediately addressed by the CPU The 16-bit system includes up to

3Mb of main memory.

main menu /me n menju / noun a list

of the primary options available

main routine /me n ru ti n/ noun a section of instructions that make up the main part of a program (NOTE: A program often consists of a main routine and several subroutines, which are called from

the main routine.)

mains electricity /me ns lek tr səti/ noun the normal domestic electricity supply to consumers (NOTE: In the UK this is 240 volts at 50Hz. In the US, it is 110

volts at 60Hz.)

main storage /me n stɔ r d'/ noun same as main memory

maintain /me n te n/ verb to ensure a system is in good condition and function-

	maintainability		206
	ing correctly well maintained well			management information service
	looked after	/ me nte nə b l ti/		/ m n d'mənt	nfə me ʃ(ə)n s v s/
	maintainability			noun a department within a company that
	noun the ability to have repairs carried out			is responsible for information and data
	quickly and efficiently if a failure occurs			processing. Abbr MIS (NOTE: In practice,
	maintenance / me ntənəns/ noun 1.			this department is often responsible for
	the task of keeping a machine in good			the computer system in a company.)
	working condition 2. tasks carried out in			management information system
	order to keep a system running, e.g. repair-			/ m n d'mənt nfə me ʃ(ə)n s stəm/
	ing faults and replacing components			noun software that allows managers in a
	maintenance contract / me ntənəns			company to access and analyse data. Abbr
	kɒntr kt/ noun an arrangement with a			MIS
	repair company that provides for regular			manager / m n d'ə/			noun a	user-
	checks and special	repair	prices in the	friendly front end software that				allows
	event of a fault
				easy access to operating system com-
	maintenance release / me ntənəns
				mands
	r li s/ noun a program revision that cor-			Manchester	coding		/ m ntʃestə
	rects a minor problem or bug but does not
				kɒd ŋ/ noun a method of encoding data
	offer any major new features The main-
				and timing signals that is used in commu-
	tenance release of the database program,
				nications. The first half of the bit period in-
	version 2.01, corrects the problem with the
				dicates the value of the bit (1 or 0), and the
	margins.
				second half is used as a timing signal.
	maintenance routine / me ntənəns
				Mandlebrot set / m nd(ə)lbrɒt set/
	ru ti n/ noun a software diagnostic tool
	used by an engineer during preventative			noun a mathematical		equation that is
				called recursively to generate a set of val-
	maintenance operations
				ues. When plotted these form a fractal im-
	major cycle / me d'ə sa k(ə)l/ noun
	the minimum access time of a mechanical			age. fractal
				manipulate /mə n pjυ le t/ verb to
	storage device
	majordomo / me d'ə dəυməυ/ noun			move, edit and change text or data An
	same as listserv			image processor that captures, displays
	make directory / me k da rekt(ə)ri/			and manipulates video images.
	noun full form of MD			manipulation	/mə n pjυ le ʃ(ə)n/
	male connector /me l kə nektə/ noun			noun the process of moving or editing or
	a plug with conducting pins that can be in-			changing text or data The high-speed
	serted into a female connector to provide			database management program allows the
	an electrical connection			manipulation of very large amounts of da-
	malfunction /m l f ŋkʃən/ noun (of			ta.
	hardware or software) the fact of not			man machine interface / m n mə
	working correctly The data was lost due			ʃi n ntəfe s/ noun full form of MMI
	to a software malfunction. verb not to			mantissa /m n t sə/ noun the fraction-
	work properly Some of the keys on the			al part of a number The mantissa of the
	keyboard have started to malfunction.
				number 45.897 is 0.897.
	malfunctioning /m l f ŋkʃən ŋ/ ad-
				manual / m njuəl/		noun a document
	jective not working properly
				containing instructions		about the		opera-
	malfunction routine		/m l f ŋkʃən
				tion of a system or piece of software The
	ru ti n/ noun a software routine used to
				manual is included with the system.
	find and help diagnose the cause of an er-			manual data processing / m njυəl
	ror or fault
	MAN /m n/ noun a network extending			de tə prəυses ŋ/ noun the process of
				sorting and processing information with-
	over a limited geographical area, normally
				out the help of a computer
	a city. Full form metropolitan area net-
				manual entry / m njυəl entri/ noun
	work. Compare LAN, WAN
	manageable / m n d'əb(ə)l/ adjec-			the act of entering data into a computer by
	tive that can be dealt with easily			an operator via a keyboard
	processing problems which are still man-			manual input / m njυəl npυt/ noun
	ageable.			same as manual entry

207	mask register

manually / m njυəli/ adverb done by hand, not automatically The paper has to be fed into the printer manually.

map /m p/ noun a diagram representing the internal layout of a computer’s memory or communications regions verb 1. to retrieve data and display it as a map 2. to represent a network directory path on a remote computer with a local drive letter, enabling a user to view the contents of the remote directory by simply typing in the drive letter rather than the often long and complex directory path 3. to represent a network printer connected to another computer on a network with a local printer identifier, so a user can treat the remote network printer as if it is directly connected to their computer 4. to connect to a disk drive or a printer that is connected to another computer on a network. texture mapping 5. to transform a two-dimen- sional image into a three-dimensional form that can then be rotated or manipulated 6. (in an image) to transform a graphical object from one coordinate system to another so that it can be displayed; e.g., to transform a three-dimensional wire frame model to a solid shaded object. texture mapping

MAPI / em e pi a / noun a set of standards, developed by Microsoft, that defines how electronic mail is sent and delivered. Full form mail application programming interface

MAR / em e ɑ / noun a register within the CPU that contains the next location to be accessed. Full form memory address register

marching display /mɑ tʃ ŋ d sple / noun a display device that contains a buffer to show the last few characters entered

margin / mɑ d' n/ noun 1. the blank space around a section of printed text

When typing the contract leave wide margins. to set the margin to define the size of a margin 2. an extra time or space margin of error / mɑ d' n əv erə/ noun the number of mistakes that is acceptable in a document or in a calculation

mark /mɑ k/ noun 1. a sign put on a page to show something 2. a transmitted signal that represents a logical one or true condition verb to put a mark on something mark block / mɑ k blɒk/ verb to put a block marker at the beginning and end of a block of text

marker / mɑ kə/ noun a code inserted in

a file or text to indicate a special section mark sense / mɑ k sens/ verb to write

characters with conductive or magnetic

ink so that they are then machine readable mark sense device / mɑ k sens d

va s/ noun a device that reads data from special cards containing conductive or

magnetic marks

mark sense reader / mɑ k sens

ri də/ noun same as mark sense device mark sensing card / mɑ k sens ŋ

kɑ d/ noun a preprinted card with spaces

for mark sense characters

mark space / mɑ k spe s/ noun a twostate transmission code using a mark and a space (without a mark) as signals markup / mɑ k p/ noun the addition of instructions for layout and style to a text that is to be printed out

markup language / mɑ k pl ŋ w d'/ noun a computer coding system that gives instructions relating to the layout and style to be used for a document marquee /mɑ ki / noun 1. (in graphics) the area selected by a selection tool 2. (in a website) a piece of text that moves slowly across the screen, used as a special feature of a webpage

mask /mɑ sk/ noun 1. an integrated circuit layout that is used to define the pattern to be etched or doped onto a slice of semiconductor A mask or stencil is used to transfer the transistor design onto silicon.

2. a pattern of binary digits used to select various bits from a binary word. A one in the mask retains that bit in the word. verb to cover an area of something with something

maskable / mɑ skəb(ə)l/ adjective that

can be masked

maskable interrupt / mɑ skəb(ə)lntər pt/ noun an interrupt which can be

activated by using an interrupt mask mask bit / mɑ sk b t/ noun one bit in a mask, used to select the required bit from

a word or string

masked ROM / mɑ skt rɒm/ noun a read-only memory device that is programmed during manufacture, by depositing metal onto selected regions dictated by the shape of a mask

masking / mɑ sk ŋ/ noun an operation

used to select various bits in a word mask register /mɑ sk red' stə/ noun

a storage location in a computer that contains the pattern of bits used as a mask

mass production

208

mass production /m s prə d kʃən/ noun the process of manufacturing large quantities of goods mass production of

monitors

mass storage /m s stɔ r d'/ noun the storage and retrieval of large amounts of data

mass storage device / m sstɔ r d' d va s/ noun a computer back-

ing store device that is able to store large amounts of data The hard disk is a mass storage device.

mass storage system / m sstɔ r d' s stəm/ noun a data storage

system that can hold more than one million million bits of a data

master / mɑ stə/ adjective referring to the main or most important device or person in a system The master computer controls everything else. verb to learn and understand a language or process

We mastered the new word-processor quite

quickly.

master card / mɑ stə kɑ d/ noun the first punched card in a pack that provides

information about the rest of the pack master clock / mɑ stə klɒk/ noun a

timing signal to which all components in a

system are synchronised

master computer / mɑ stə kəmpju tə/ noun a computer in a multiprocessor system that controls the other processors and allocates jobs

master control program / mɑ stə kən trəυl prəυ r m/ noun software that

controls the operations in a system. Abbr

MCP

master data / mɑ stə de tə/ noun ref-

erence data which is stored in a master file master disc / mɑ stə d sk/ noun a

glass disc onto which a laser etches pits to represent data, and which is then used to create plastic compact discs ready for dis-

tribution

master disk / mɑ stə d sk/ noun 1. a disk containing all the files for a task 2. a disk containing the code for a computer’s operating system that must be loaded be-

fore the system will operate

master file / mɑ stə fa l/ noun a set of all the reference data required for an application, which is updated periodically mastering / mɑ stər ŋ/ noun a process used to convert finished data to a master disc

master/master computer system

/ mɑ stə mɑ stə kəm pju tə s stəm/

noun a system in which each processor is a master, dedicated to one task

master program file / mɑ stəprəυ r m fa l/ noun a magnetic medi-

um which contains all the programs required for an application

master/slave computer system

/ mɑ stə sle v kəm pju tə s stəm/ noun a system with a master controlling computer and a slave that takes commands

from the master

master tape / mɑ stə te p/ noun a magnetic tape which contains all the vital operating system routines, loaded by the initial program loader once when the com-

puter is switched on or hard reset master terminal / mɑ stə t m n(ə)l/

noun one terminal in a network which has priority over any other, used by the system manager to set up the system or carry out privileged commands The system manager uses the master terminal to restart the system.

mat /m t/ noun a plain coloured border that is displayed around an image that is smaller than the window in which it is displayed

match /m tʃ/ verb 1. to search through a database for a similar piece of informa-

tion 2. to set a register equal to another material /mə t əriəl/ noun a substance

which can be used to make a finished product Gold is the ideal material for electrical connections.

math /m θ/ noun US same as mathematics (informal)

mathematical / m θə m t k(ə)l/ adjective referring to mathematics

mathematical model

/ m θəm t k(ə)l mɒd(ə)l/ noun a representation of a system using mathematical ideas and formulae

mathematical subroutines

/ m θəm t k(ə)l s bru ti nz/ plural noun library routines that carry out standard mathematical functions such as square root, logarithm, cosine and sine mathematics / m θə m t ks/ noun the science of the relationship between numbers, their manipulation and organisation to (logically) prove facts and theories.

algebra

maths chip / m θs tʃ p/ noun a dedicated IC that can be added to a system to carry out mathematical functions far more rapidly than a standard CPU, speeding up the execution of a program

209

mean

maths coprocessor / m θs kəυprəυsesə/ noun same as maths chip

matrix / me tr ks/ noun 1. an array of numbers or data items arranged in rows and columns 2. an array of connections between logic gates providing a number of possible logical functions 3. a pattern of the dots that make up a character on a computer screen, dot-matrix or laser printer matrix printer / me tr ks pr ntə/ noun dot-matrix printer

matrix rotation / me tr ks rəυte ʃ(ə)n/ noun the process of swapping the rows with the columns in an array, equal to rotating by 90 degrees

matrix transform / me tr ks tr nsfɔ m/ noun a mathematical process used to rotate a line in any direction. The process involves multiplying a 4x4 transform matrix with the matrix of the line’s coordinates.

matte /m t/ noun (in video or film) a specified region within an image, which can be coded to appear transparent or opaque. A matte is reveals or masks off part of an image in another plane, and is normally used for special effects in which an object is photographed against a specially coloured background that is then replaced with another image to give the impression that the object appears against that image. chroma key

matter / m tə/ noun the main section of text on a page as opposed to titles or headlines

MAU abbr multistation access unit maximise / m ks ma z/, maximize verb (in MS-Windows) to expand an application icon back to its original display window. Compare minimise maximum / m ks məm/ noun the highest value used or that is allowed maximum capacity / m ks məm kəp s ti/ noun the greatest amount of data that can be stored

maximum transmission rate

/ m ks məm tr nz m ʃ(ə)n re t/ noun the greatest amount of data that can be transmitted every second

maximum users / m ks məmju zəz/ plural noun the greatest number of users that a system can support at any one time

Mb abbr megabit MB abbr megabyte

Mbps abbr megabits per second

MBR / em bi ɑ / noun a register in a CPU that temporarily buffers all inputs and outputs. Full form memory buffer register

Mbyte / em ba t/ abbr megabyte The latest model has a 30Mbyte hard disk.

MCA / em si e / a trade name for the expansion bus within IBM’s PS/2 range of personal computers that has taken over from the older ISA/AT bus. MCA is a 32bit bus that supports bus master devices. Full form Micro Channel Architecture

abbr media control architecture

MCA chipset / em si e tʃ pset/ noun the number of electronic components required to manage the timing and data sig-

nals over an MCA expansion bus

MCGA / em si d'i e / noun a colour graphics adapter standard fitted in low-end IBM PS/2 computers. Full form multicolor graphics adapter

MCI / em si a / noun an interface that allow any program to control a multimedia device such as a sound card or video clip.

Full form media control interface

MCI device / em si a d va s/ noun a recognised multimedia device that is installed in a computer with the correct driv-

ers

MCP / em si pi d'ɔ nt/ abbr master control program

MD / em di / noun a DOS command used to create a new directory on a disk. Full form make directory

MDA / em di e / noun a video adapter standard used in early PC systems that could display text in 25 lines of 80 columns. Full form monochrome display adapter

MDK / em di ke / noun a product developed by Microsoft that allows developers to produce multimedia applications more easily using the supplied libraries of routines to control video playback, process images and display text. Full form multimedia developer’s kit

MDR / em di ɑ / noun a register in a CPU that holds data before it is processed or moved to a memory location. Full form

memory data register

MDRAM / em di r m/ noun a type of high-performance memory normally used in video adapter cards to provide fast graphic display. Full form multibank dynamic random access memory mean /mi n/ noun, adjective the average value of a set of numbers or values verb

mean time between failures

210

to signify something The message DISK FULL means that there is no more room on the disk for further data.

mean time between failures / mi n ta m b twi n fe ljəz/ noun full form of

MTBF

mean time to failure / mi n ta m təfe ljə/ noun full form of MTF

measure / me'ə/ noun 1. a way of calculating size or quantity 2. the total width of a printed line of text 3. a type of action

to take measures to prevent something happening to act to stop something happening verb 1. to find out the size or quantity of something 2. to be of a certain size or quantity

measurement / me'əmənt/ noun a way of judging something Performance measurement or measurement of performance is carried out by running a benchmark program.

measurements / me'əmənts/ plural noun size to write down the measurements of a package

mechanical /m k n k(ə)l/ adjective referring to machines

mechanical mouse /m k n k(ə)l maυs/ noun pointing device that is operated by moving it across a flat surface. As the mouse is moved, a ball inside spins and turns two sensors that feed the horizontal and vertical movement back to the computer. Compare optical mouse mechanism / mekə n z(ə)m/ noun a piece of machinery The printer mechanism is very simple.

medallion /mə d liən/ noun the microchip inside a smart card

media / mi diə/ plural noun physical materials that can be used to store data

Computers can store data on a variety of media, such as disk or CD-ROM.

media access control / mi diəkses kən trəυl/ noun a sublayer within

the data-link layer of the OSI network model that provides access to the transmission media. Abbr MAC

media control architecture / mi diə kən trəυl ɑ k tektʃə/ noun full form of

MCA

media control interface / mi diə kəntrəυl ntəfe s/ noun full form of MCI

media conversion / mi djə kənv ʃ(ə)n/ noun the process of copying data from one type of storage medium to another

media error / mi djə erə/ noun a fault in the storage media that corrupts data

Media Player / mi diə ple ə/ a trade name for a Windows utility program that allows a user to control installed multimedia hardware including video disc or audio CDs, or play back multimedia files including sound, animation and video files

MediaServer / mi diə s və/ a trade name for a system developed by Netscape to provide audio and video delivery over the Internet

medical telematics / med k(ə)l telm t ks/ noun the development and use of computer networks to enable medical data to be accessed from different countries and exchanged between one country and another

medium / mi diəm/ adjective middle or average a medium-sized computer system noun any physical material that can be used to store date

medium model / mi diəm mɒd(ə)l/ noun memory model of the Intel 80x86 processor family that allows 64Kb of data and up to 1MB of code

medium scale integration

/ mi diəm ske l nt re ʃ(ə)n/ noun an integrated circuit with 10 – 500 components. Abbr MSI

medium speed / mi diəm spi d/ noun a data communication speed between 2400 and 9600 bits per second (NOTE: Medium speed transmission describes the maximum rate of transfer for a normal voice grade channel.)

meet /mi t/ noun a logical function whose output is true if both inputs are true

meg /me / noun same as megabyte

(informal) This computer has a ninetymeg hard disk.

mega- /me ə/ prefix 1. one million 2. 1,048,576 (equal to 220) and used only in computing and electronic related applications

megabit / me əb t/ noun equal to 1,048,576 bits. Abbr Mb

megabits per second / me əb ts psekənd/ noun a number of million bits

transmitted every second. Abbr Mbps megabyte / me əba t/ noun a measure of the data capacity of a storage device that is equal to 1,048,576 bytes or 220 bytes. Megabytes are used to measure the storage capacity of hard disk drives or main memory (RAM). Abbr MB

211	memory effect

‘Doing this reduced a bitmap of my desktop from 2.25 megabytes to a 58K GIF’ [The Guardian]

mega floating point instructions per second / me ə fləυt ŋ pɔ nt nstr kʃənz p s kɒnd/ noun full form

of MFLOPS

megaflop / me əflɒp/ noun a measure of computing power and speed equal to one million floating point instructions per second. Abbr MFLOPS

megahertz / me ə h ts/ noun a measure of frequency equal to one million cycles per second. Abbr MHz

megapixel display /me ə p ks(ə)l dsple / noun a display adapter and monitor that are capable of displaying over one million pixels. This means a resolution of at least 1,024x1,024 pixels.

Megastream / me əstri m/ a trade name for a data link provided by British Telecom that offers data transfer at rates up to 8Mbits/second

Mega VGA / me ə vi d'i e / noun a 256 colour Super VGA mode with a resolution of 1024x768 that requires one megabyte of video RAM

member / membə/ noun 1. one object on a page of a multimedia book 2. an individual record or item in a field membrane keyboard / membre nki bɔ d/ noun a keyboard that uses a thin plastic or rubber sheet with key shapes moulded into it. When the user presses on a key, it activates a pressure sensor. (NOTE: The keys in a membrane keyboard have less travel than normal mechanical keys, but since they have no moving parts, they are more robust and reliable.)

memo field / meməυ fi ld/ noun a field in a database or text window in an application that allows a user to add comments or a memo about the entry

memorise / memə ra z/, memorize verb to remember or to retain in the memory

memory / mem(ə)ri/ noun storage space in a computer system or medium that is capable of retaining data or instructions

‘The lower-power design, together with an additional 8Kb of on-board cache memory, will increase the chip’s performance to 75 million instructions per second.’ [Computing]

‘…when a program is loaded into memory, some is used for the code, some for the permanent data, and some is reserved for the stack which grows and shrinks for function calls and local data’ [Personal Computer World]

memory access time / mem(ə)rikses ta m/ noun a time delay between requesting access to a location and actually gaining access to it

memory address register

/ mem(ə)ri ə dres red' stə/ noun full form of MAR

memory allocation / mem(ə)riləke ʃ(ə)n/ noun a process in which an

operating system provides an application with the memory it requires in order to run

memory backup capacitor

/ mem(ə)ri b k p kə p s tə/ noun a very high-capacitance, small device that can be used instead of a battery to provide power for volatile RAM chips for up to two weeks

memory bank / mem(ə)ri b ŋk/ noun a number of smaller storage devices connected together to form one large area of memory

memory board / mem(ə)ri bɔ d/ noun a printed circuit board containing memory chips

memory buffer register / mem(ə)rib fə red' stə/ noun full form of MBR

memory bus / mem(ə)ri b s/ noun a bus carrying address data between a CPU and memory devices

memory capacity / mem(ə)ri kəp s ti/ noun the number of bits or bytes that can be stored within a memory device memory cell / mem(ə)ri sel/ noun the smallest location in a memory that can be individually accessed

memory chip / mem(ə)ri tʃ p/ noun an electronic component that is able to store binary data

memory cycle / mem(ə)ri sa k(ə)l/ noun the period of time from when the CPU reads or writes to a location and to when the action is actually performed

memory data register / mem(ə)ride tə red' stə/ noun full form of MDR

memory diagnostic / mem(ə)rida ə nɒst k/ noun a software routine that checks each memory location in main memory for faults

memory dump / mem(ə)ri d mp/ noun a printout of all the contents of an area of memory

memory edit / mem(ə)ri ed t/ verb to change the contents of various memory locations

memory effect / mem(ə)ri fekt/ noun a feature of nickel-cadmium, or

memory expansion

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NiCad, rechargeable batteries where the battery’s capacity to hold charge is reduced if the battery is recharged before it has been fully discharged. For example, if a battery still has half its original charge when it is recharged, it appears only to have the capacity to carry the new halfcharge rather than a full charge. It seems, in effect, to have a memory of the last level of its charge. (NOTE: This problem was particularly noticeable on older NiCad batteries. Modern NiCad batteries suffer very little from this effect, and other types of battery such as the lithium ion battery

do not suffer from it at all.)

memory expansion / mem(ə)ri ksp nʃ(ə)n/ noun the action of adding more electronic memory chips to a computer

memory hierarchy / mem(ə)riha ərɑ ki/ noun the different types of memory available in a system, arranged according to their capacity and access time

memory-intensive software

/ mem(ə)ri n tens v sɒftweə/ noun software that uses large amounts of RAM or disk storage during run-time, such as programs whose entire code has to be in main memory during execution

memory management / mem(ə)rim n d'mənt/ noun software that con-

trols and regulates the flow and position in memory of files and data

memory management unit

/ mem(ə)ri m n d'mənt ju n t/ noun full form of MMU

memory map / mem(ə)ri m p/ noun a diagram indicating the allocation of address ranges to various memory devices, such as RAM, ROM and memory-mapped input/output devices memory-mapped / mem(ə)ri m pt/ adjective referring to a computer’s input or output devices that have addresses allocated to them so that they can be accessed as if they were a memory location A memory-mapped screen has an address allocated to each pixel, allowing direct access to the screen by the CPU.

memory-mapped input/output

/ mem(ə)ri m pt npυt aυtpυt/ noun same as memory-mapped I/O memory-mapped I/O / mem(ə)rim pt a əυ/ noun an I/O port which can be accessed as if it were a memory location within the CPU’s normal address range

memory model / mem(ə)ri mɒd(ə)l/ noun a method used in a program to address the code and data that is used within that program. The memory model defines how much memory is available for code and data. (NOTE: Processors with a segmented address space, like the Intel 80x86 range, can support multiple mem-

ory models.)

memory page / mem(ə)ri pe d'/ noun one section of a main store containing data

or programs that is divided into pages memory protect / mem(ə)ri prə tekt/

noun a feature on most storage systems to prevent the accidental overwriting of data

memory-resident software

/ mem(ə)ri rez d(ə)nt sɒftweə/ noun

same as resident software

memory stick / mem(ə)ri st k/ noun a tiny memory expansion device, developed by Sony, that can store up to 128Mb of data, often used in MP3 music players and digital cameras

memory switching system

/ mem(ə)ri sw tʃ ŋ s stəm/ noun a system which communicates information, stores it in memory and then transmits it according to instructions

memory workspace / mem(ə)riw kspe s/ noun the amount of extra

memory required by a program to store

data used during execution

menu / menju / noun a list of options or

programs available to the user menu-bar / menju bɑ / noun (in a

GUI) a list of options available to a user which are displayed on a horizontal line along the top of the screen or window. Each menu option activates a pull-down

menu.

menu-driven software / menjudr v(ə)n sɒftweə/ noun a program in

which commands or options are selected from a menu by the operator rather than

typed in by the user at a prompt

menu item / menju a təm/ noun one

of the choices in a menu

menu selection / menju s lekʃən/ noun the act of choosing commands from

a list of options presented to the operator menu shortcut / menju ʃɔ tk t/

noun a key combination of two or more keys that is the same are selecting a menu

option

merchant account / m tʃənt əkaυnt/ noun a bank account that enables

its user to deposit payments made by credit

213

MFM

card, used especially for trading on the In-

ternet

mercury delay line / m kjυri d lela n/ noun an obsolete method of storing serial data as pulses in a length of mercury

(NOTE: The data was constantly read, regenerated and fed back into the input.) merge /m d'/ verb to combine two data files retaining an overall order The system automatically merges text and illustrations into the document. (NOTE: merges –

merging – merged)

merge sort / m d' sɔ t/ noun a software application in which the sorted files are merged into a new file

mesh /meʃ/ noun any system with two or more possible paths at each interconnec-

tion

mesh model /meʃ mɒd(ə)l/ noun a graphical object that is displayed as a mesh, with crossing lines. wire frame model (NOTE: The mesh is actually created from polygons and can be used to

shade the object.)

mesh network /meʃ netw k/ noun a method of connecting several machines together, where each device is directly con-

nected to every other device in the network message / mes d'/ noun 1. a piece of

information sent from one person to another 2. a defined amount of information

message authentication code

/ mes d' ɔ θent ke ʃ(ə)n kəυd/ noun

full form of MAC

message board / mes d' bɔ d/ noun

same as bulletin board

message box / mes d' bɒks/ noun a small window that is displayed on screen to warn of an event, condition or error

message code authentication

/ mes d' kəυd ɔ θent ke ʃ(ə)n/ noun a coding system that enables the author of an email message to be identified and en-

sures that the message is genuine message format / mes d' fɔ m t/

noun a set of predetermined rules defining the coding, size and speed of transmitted messages

message handling service

/ mes d' h ndl ŋ s v s/ noun full

form of MHS

message header / mes d' hedə/ noun a sequence of data at the beginning of a message that contains routing and des-

tination information

message routing / mes d' raυt ŋ/ noun selection of a suitable path between

the source and destination of a message in

a network

message slot / mes d' slɒt/ noun the number of bits that can hold a message that

circulates around a ring network message text / mes d' tekst/ noun in-

formation that concerns the user at the destination without routing or network control data

message transfer agent / mes d'tr nsf e d'ənt/ noun full form of

MTA

messaging / mes d' ŋ/ noun the process of sending a message to other people,

e.g. by computer, telephone or pager metabit / metəb t/ noun an extra identi-

fying bit for each data word metacompilation / metəkɒmp

le ʃ(ə)n/ noun the process of compiling a program that will compile other programs

when executed

metacompiler / metəkɒm pa lə/ noun a compiler that is used to create another

compiler

metafile / metəfa l/ noun 1. a file that contains other files The operating system uses a metafile to hold data that defines where each file is stored on disk. 2. a file that defines or contains data about oth-

er files

metalanguage / metə l ŋ w d'/ noun a language that describes a programming language

metal oxide semiconductor

/ met(ə)l ɒksa d semikən d ktə/ noun full form of MOS

metal oxide semiconductor field effect transistor / met(ə)l ɒksa dsemikənd ktə fi ld fekt tr n z stə/

noun full form of MOSFET

meter – power supply / mi tə paυə sə pla / noun a utility within Windows that indicates how much power is left in a laptop’s battery and whether a laptop is running from a battery or mains electricity power

metropolitan area network

/ metrəpɒl t(ə)n eəriə netw k/ noun

full form of MAN

MFLOPS / em flɒps/ noun a measure of computing speed calculated as the number of floating point instructions that can be processed each second. Full form mega floating point instructions per second

MFM / em ef em/ noun a method of storing data on magnetic media, e.g. a magnetic disk that encodes the data bit according