Dictionary of Computing - 5th Edition

representing red, green and blue, that together form a single pixel on a colour

screen

photo- /fəυtəυ/ prefix light

PhotoCD / fəυtəυ si di / noun a standard developed to store 35 mm photographic slides or negatives in digital format on a CD-ROM

photodigital memory /fəυtəυd d' t(ə)l mem(ə)ri/ noun a computer

memory system that uses a laser to write data onto a piece of film which can then be read many times but not written to again.

Also called WORM

photorealistic / fəυtəυriə l st k/ adjective referring to a computer image that has almost the same quality and clarity as

a photograph

photoresist / fəυtəυr z st/ noun a chemical or material that hardens into an etch resistant material when light is shone on it To make the PCB, coat the board with photoresist, place the opaque pattern above, expose, then develop and etch,

leaving the conducting tracks. phototypesetter / fəυtəυ ta psetə/

noun a device that can produce very highresolution text on photosensitive paper or

film

physical address / f z k(ə)l ə dres/ noun a memory address that corresponds to a hardware memory location in a memory device

physical database / f z k(ə)lde təbe s/ noun the organisation and

structure of a stored database

physical layer / f z k(ə)l le ə/ noun the lowest ISO/OSI standard network layer that defines rules for bit rate, power and medium for signal transmission

physical memory / f z k(ə)lmem(ə)ri/ noun memory fitted in a com-

puter

physical parameter / f z k(ə)l pər m tə/ noun a description of the size,

weight, voltage or power of a system physical record / f z k(ə)l rekɔ d/

noun 1. the maximum unit of data that can be transmitted in a single operation 2. all the information, including control data, for

one record stored in a computer system

physical topology / f z k(ə)l təpɒləd'i/ noun the actual arrangement of

the cables in a network

PIA / pi a e / noun a circuit which allows a computer to communicate with a peripheral by providing serial and parallel

ports and other handshaking signals required to interface the peripheral. Full form peripheral interface adapter

PIC / pi a si / noun an image compression algorithm used in Intel’s DVI video system. Full form picture image compression

pica / pa kə/ noun a typeface used on a printer to giving 10 characters to the inch PICK /p k/ noun a multi-user, multitasking operating system that runs on mainframe, mini or PC computers

pickup reel / p k p ri l/ noun an empty reel used to take the tape as it is played from a full reel

pico- /pi kəυ/ prefix one million millionth of a unit. Abbr p

picosecond / pi kəυ sekənd/ noun one million millionth of a second. Abbr pS

PICS /p ks/ noun a file format used to import a sequence of PICT files on an Apple Mac

PICT /p kt/ noun a method of storing vector graphic images, developed by Lotus for its 1–2–3 spreadsheet charts and graphs. Full form PICture

picture / p ktʃə/ noun a printed or drawn image of an object or scene This picture shows the new design. verb to visualise an object or scene Try to picture the layout before starting to draw it in.

(NOTE: pictures – picturing – pictured)

PICture / p ktʃə/ noun full form of

PICT

picture beam / p ktʃə bi m/ noun a moving electron beam in a TV that produces an image on the screen by illuminating the phosphor coating and by varying its intensity according to the received signal

picture element / p ktʃə el mənt/ noun same as pixel

picture image compression

/ p ktʃə m d' kəm preʃ(ə)n/ noun full form of PIC

picture level benchmark / p ktʃəlev(ə)l bentʃmɑ k/ noun full form of

PLB

picture object / p ktʃə ɒbd'ekt/ noun an image created with a vector drawing package and stored as vectors rather than as a bitmap

picture processing / p ktʃə prəses ŋ/ noun the analysis of information contained in an image, usually by compu-

ter or electronic methods, providing analysis or recognition of objects in the image picture transmission / p ktʃə tr nzm ʃ(ə)n/ noun the transmission of images over a telephone line

PID / pi a di / noun a device such as a bank card connected with or inserted into a system to identify or provide authorisation for a user. Full form personal identification device

pie chart / pa tʃɑ t/ noun a diagram in which ratios are shown as slices of a circle

The memory allocation is shown on this pie chart.

PIF / pi a ef/ noun a Microsoft Windows file that contains the environment settings for a particular program. Full form program information file

piggyback / p ib k/ verb to connect two integrated circuits in parallel, one on top of the other to save space Piggyback those two memory chips to boost the memory capacity.

piggyback entry / p ib k entri/ noun unauthorised access to a computer system gained by using an authorised user’s password or terminal piggybacking / p ib k ŋ/ noun the process of using transmitted messages to carry acknowledgements from a message which has been received earlier

pilot / pa lət/ adjective used as a test, which if successful will then be expanded into a full operation The company set up a pilot project to see if the proposed manufacturing system was efficient. verb to test something They are piloting the new system.

PILOT / pa lət/ noun a computer programming language that uses a text-based format and is mainly used in computeraided learning

pilot system / pa lət s stəm/ noun a system constructed to see if it can be manufactured, if it works and if the end user likes it

PIM / pi a em/ noun a software utility that stores and manages a user’s everyday data such as diary, telephone numbers, address book and notes. Full form personal information manager

pin /p n/ noun 1. one of several short pieces of wire attached to an integrated circuit package that allows the IC to be connected to a circuit board 2. a short piece of metal, part of a plug which fits into a hole

in a socket Use a three-pin plug to connect the printer to the mains.

PIN /p n/ noun a unique sequence of digits that identifies a user to provide authorisation to access a system, often used on automatic cash dispensers or with a PID or password to enter a system. Full form per-

sonal identification number pinchwheel / p ntʃwi l/ noun a small

rubber wheel in a tape machine that holds

the tape in place and prevents flutter pin-compatible / p n kəm p t b(ə)l/

adjective referring to an electronic chip that can directly replace another because the arrangement of the pins is the same and they carry the same signals It’s easy to upgrade the processor because the new

one is pin-compatible.

pincushion distortion / p nkυʃ(ə)n d stɔ ʃ(ə)n/ noun a fault with a monitor

that causes the distortion of an image displayed in which the edges curve in towards the centre

pinfeed / p nfi d/ noun same as tractor feed

PING /p ŋ/ noun a software utility that will test all the nodes on a network or Internet to ensure that they are working correctly. Full form packet Internet groper pinout / p naυt/ noun a description of the position of all the pins on an integrated circuit together with their function and signal

PIO / pi a əυ/ noun data input or output from a computer in a parallel form. Full form parallel input/output. PIPO,

PISO

pipe /pa p/ noun (in DOS and UNIX) a symbol, usually (), that tells the operating system to send the output of one command to another command, instead of displaying it

pipeline / pa pla n/ verb 1. to schedule inputs to arrive at the microprocessor when nothing else is happening, so increasing apparent speed 2. to carry out more than one task at a time: e.g., to compress and store an image on disk as it is being scanned (NOTE: pipelines – pipelining

– pipelined)

pipeline burst cache / pa pla n b stk ʃ/ noun a secondary synchronous cache that uses very high speed memory

chips, with access speeds of around 9 ns PIPO / pi a pi əυ/ noun a device that

can accept and transmit parallel data. Full form parallel input/parallel output

piracy / pa rəsi/ noun the process of copying patented inventions or copyright works

pirate / pa rət/ noun a person who copies a patented invention or a copyright work and sells it The company is trying to take the software pirates to court. verb to manufacture copies of an original copyrighted work illegally a pirated DVD or a pirated design (NOTE: pirates – pirating – pirated)

COMMENT: The items most frequently pirated are programs on magnetic disks and tapes,

which are relatively simple to copy.

pirate copy / pa rət kɒpi/ noun a copy of software or other copyright material

which has been made illegally

pirate software / pa rət sɒftweə/

noun an illegal copy of a software package PISO / pi a es əυ/ noun a device that

can accept parallel data and transmit serial data. Full form parallel input/serial output

pit /p t/ noun a bump or impression on the surface of an optical disk that represents a bit of data, created by a master disk during manufacture

pitch /p tʃ/ noun the number of characters which will fit into one inch of line, when the characters are typed in single spacing (NOTE: Pitch is used on line printers, the normal pitches available being

10, 12 and 17 characters per inch.) pitch scale factor / p tʃ ske l

f ktə/ noun an instruction to a waveform audio device to change the pitch of the sound by a factor

pix /p ks/ plural noun pictures

pixel / p ksəl/ noun the smallest single unit or point of a display whose colour or brightness can be controlled. Also called picture element

‘…adding 40 to each pixel brightens the image and can improve the display’s appearance’ [Byte]

COMMENT: In high resolution display systems the colour or brightness of a single pixel can be controlled; in low resolution systems a group of pixels are controlled at the same time.

pixelated / p ksəle t d/ adjective referring to an image on a computer or television screen that is made up of pixels, especially one that is unclear or distorted PLA / pi el e / noun an integrated circuit that can be permanently programmed to perform logic operations on data using a matrix of links between input and output pins. Full form programmable logic array

COMMENT: A PLA consists of a large matrix of paths between input and output pins, with logic gates and a fusible link at each connection point that can be broken or left to conduct when programming to define a function from input to output.

place /ple s/ noun the position of a digit within a number

plain old telephone service / ple n əυld tel fəυn s v s/ noun full form of

POTS

plaintext / ple n tekst/ noun text or information that has not been encrypted or coded The messages were sent as plaintext by telephone. Opposite ciphertext

plan /pl n/ noun 1. an organised way of doing something 2. a drawing which shows how something is arranged or how something will be built verb to organise carefully how something should be done

(NOTE: planning – planned)

PLAN /pl n/ noun a low-level programming language

planar / ple nə/ adjective referring to a method of producing integrated circuits by diffusing chemicals into a slice of silicon to create the different components noun referring to graphical objects or images arranged on the same plane

plane /ple n/ noun one layer of an image that can be manipulated independently within a graphics program

planner / pl nə/ noun a software program that allows appointments and important meetings to be recorded and arranged in the most efficient way

planning / pl n ŋ/ noun the activity of organising how something should be done

long-term planning or short-term planning

plant /plɑ nt/ verb to store a result in memory for later use

plasma display / pl zmə d sple / noun same as gas discharge display

COMMENT: This is a thin display usually used in small portable computers.

plastic bubble keyboard / pl st kb b(ə)l ki bɔ d/ noun a keyboard whose

keys are small bubbles in a plastic sheet over a contact which when pressed completes a circuit

COMMENT: These are very solid and cheap keyboards but are not ideal for rapid typing.

platform / pl t fɔ m/ noun a standard type of hardware that makes up a particular range of computers This software will only work on the IBM PC platform.

platform independence / pl tfɔ mnd pendəns/ noun the fact that soft-

ware or a network can work with or connect to different types of incompatible hardware

platter / pl tə/ noun one disk within a hard disk drive

COMMENT: The disks are made of metal or glass and coated with a magnetic compound; each platter has a read/write head that moves across its surface to access stored data.

play back / ple b k/ verb to read data or a signal from a recording After you have recorded the music, press this button to play it back and hear what it sounds like.

playback head / ple b k hed/ noun a piece of equipment that reads signals recorded on a storage medium and usually converts them to an electrical signal disk playback head

playback rate scale factor

/ ple b k re t ske l f ktə/ noun 1. (in waveform audio) sound played back at a different rate, directed by another application, to create a special effect 2. (in video displayed on a computer) the point at which video playback is no longer smooth and appears jerky because of missed frames

playback speed / ple b k spi d/ noun the rate at which tape travels past a playback head

PLB / pi el bi / noun benchmark used to measure the performance (not the quality) of a graphics adapter or workstation. Full form picture level benchmark

PLD abbr programmable logic device plex database / pleks de təbe s/ noun a database structure in which data items can be linked together

plex structure / pleks str ktʃə/ noun a network structure or data structure in which each node is connected to all the others

PL/M / pi el em/ noun a high level programming language derived for use on microprocessors. Full form programming language for microprocessors

plot /plɒt/ noun a graph or map verb to draw an image (especially a graph) based on information supplied as a series of coordinates

plotter / plɒtə/ noun a computer peripheral that draws straight lines between two coordinates

COMMENT: Plotters are used for graph and diagram plotting and can plot curved lines as a

number of short straight lines.

plotter driver / plɒtə dra və/ noun dedicated software that converts simple instructions issued by a user into complex control instructions to direct the plotter plotter pen / plɒtə pen/ noun an instrument used in a plotter to mark the paper with ink as it moves over the paper plotting mode / plɒt ŋ məυd/ noun the ability of some word-processors to produce graphs by printing a number of closely spaced characters rather than individual pixels, which results in a broad lowresolution line

plug /pl / noun a connector with protruding pins that is inserted into a socket to provide an electrical connection The printer is supplied with a plug. verb plug in to make an electrical connection by pushing a plug into a socket No wonder the computer does nothing, you have not plugged it in at the mains.

plug and play / pl ən ple / noun a facility in PCs that allows a user to plug a new adapter card into their PC without having to configure it or set any switches. Abbr PNP

plug-compatible /pl kəmp təb(ə)l/ adjective referring to equipment that can work with several different types of computer, so long as they have the correct type of connector

plug-compatible manufacturer

/ pl kəm p t b(ə)l m njυ f ktʃərə/ noun full form of PCM

plug-in / pl n/ noun a program that works with a web browser to increase the functionality of the browser. browser, helper application

plug-in unit / pl n ju n t/ noun a small electronic circuit that can be simply plugged into a system to increase its power plus /pl s/, plus sign / pl s sa n/ noun a printed or written sign (+) showing that figures are added or showing a positive value

PLV / pi el vi / noun the highest-quality video compression algorithm used with DVI full-motion video sequences. Full form production level video

PMOS / pi mɒs/ noun a metal oxide semiconductor transistor that conducts via a small region of p-type semiconductor. Full form p-channel metal oxide semiconductor

PMS / pi em es/ abbr Pantone Matching System

PNP / pi en pi / abbr plug and play pnp transistor / pi en pi tr n z stə/ noun the layout of a bipolar transistor whose collector and emitter are of p-type semiconductor and whose base is n-type semiconductor

pointer / pɔ ntə/ noun 1. a variable in a computer program that contains the address to a data item or instruction Increment the contents of the pointer to the address of the next instruction. 2. a graphical symbol used to indicate the position of a cursor on a computer display Desktop publishing on a PC is greatly helped by the use of a pointer and mouse.

pointer file / pɔ ntə fa l/ noun a file of pointers referring to large amounts of stored data

pointing device / pɔ nt ŋ d va s/ noun an input device that controls the position of a cursor on screen as it is moved by the user. mouse

point of presence / pɔ nt əvprezəns/ noun full form of POP

point-of-sale / pɔ nt əv se l/ noun a place in a shop where goods are paid for. Abbr POS

point sampling /pɔ nt sɑ mpl ŋ/ noun a method of adding texture and shading to a three-dimensional scene or object, in which the algorithm calculates the perceived depth, position and shade of each point on the image and applies a texture map pixel, or texel, to that point

point size / pɔ nt sa z/ noun (in typography) a unit of measure equal to 1/72inch, used to measure type or text

point to point / pɔ nt tə, tυ/ noun 1. a direct link between two devices 2. communications network in which every node is directly connected to every other node

point to point protocol / pɔ nt təpɔ nt prəυtəkɒl/ noun full form of PPP

point-to-point tunneling protocol

/pɔ nt tə, tυ pɔ nt t n(ə)l ŋ/ noun full form of PPTP

poke /pəυk/ noun a computer instruction that modifies an entry in a memory by writing a number to an address in memory

Poke 1423,74 will write the data 74 into location 1423. Compare peek

POL abbr problem-orientated language polar / pəυlə/ adjective referring to poles

polar coordinates / pəυlə kəυɔ d nəts/ noun a system of defining positions as an angle and distance from the origin

polarised edge connector

/ pəυləra zd ed' kə nektə/ noun an edge connector that has a hole or key to prevent it being plugged in the wrong way round

polarised plug / pəυləra zd pl / noun a plug which has a feature (usually a peg or a special shape) which allows it to be inserted into a socket only in one way

polarity /pəυ l rəti/ noun the definition of direction of flow of flux or current in an object

polarity test /pəυ l rəti test/ noun a check to see which electrical terminal is positive and which negative

policy / pɒl si/ noun acceptable use policy

Polish notation / pəυl ʃ nəυ te ʃ(ə)n/

reverse Polish notation

poll /pəυl/ verb (of a computer) to determine the state of a peripheral in a network polled interrupt / pəυld ntər pt/ noun an interrupt signal determined by polling devices

polling / pəυl ŋ/ noun a system of communication between a controlling computer and a number of networked terminals (the computer checks each terminal in turn to see if it is ready to receive or transmit data, and takes the required action)

COMMENT: The polling system differs from other communications systems in that the computer asks the terminals to transmit or receive, not the other way round.

polling characters / pəυl ŋ

k r ktəz/ plural noun a special sequence of characters for each terminal to be polled, which ensures that when a terminal recognises its sequence, it responds polling interval / pəυl ŋ ntəv(ə)l/ noun a period of time between two polling operations

polling list / pəυl ŋ l st/ noun the order in which terminals are to be polled by a computer

polling overhead / pəυl ŋ əυvəhed/ noun the amount of time spent by a computer calling and checking each terminal in a network

polygon / pɒl ən/ noun a graphics shape with three or more sides

polygon mesh model / pɒl ən meʃmɒd(ə)l/ noun same as wire frame model

polynomial code / pɒli nəυmiəl kəυd/ noun an error detection system that uses a set of mathematical rules applied to the message before it is transmitted and again when it is received to reproduce the original message

polyphony /pə l fəni/ noun a device that can play more than one musical note at a time

pop /pɒp/ verb to read and remove the last piece of data from a stack

POP /pɒp/ noun telephone access number for a service provider that can be used to connect to the Internet via a modem. Full form point of presence

POP 2 / pɒp tu / noun a high level programming language used for list processing applications

POP 3 / pɒp θri / noun a system used to transfer electronic mail messages between a user’s computer and a server at an ISP pop-down menu / pɒp daυn menju / noun a menu that can be displayed on the screen at any time by pressing the appropriate key, usually displayed over material already on the screen. Also called pop-up menu

populate / pɒpjυle t/ verb to fill the sockets on a printed circuit board with components

pop-up menu / pɒp p menju / noun same as pop-down menu

pop-up window / pɒp p w ndəυ/ noun a window that can be displayed on the screen at any time on top of anything that is already on the screen

‘…you can use a mouse to access pop-up menus and a keyboard for word processing’ [Byte]

port /pɔ t/ noun a socket or physical connection allowing data transfer between a computer’s internal communications channel and another external device portability / pɔ tə b l ti/ noun an extent to which software or hardware can be used on several systems

‘…although portability between machines is there in theory, in practice it just isn’t that simple’ [Personal Computer World]

portable / pɔ təb(ə)l/ noun a compact self-contained computer that can be carried around and used either with a battery pack or mains power supply adjective referring to any hardware or software or

data files that can used on a range of different computers

portable document format

/ pɔ təb(ə)l dɒkjυmənt fɔ m t/ noun full form of PDF

portable operating system interface / pɔ təb(ə)l ɒpəre t ŋ s stəmntəfe s/ noun full form of POSIX

portable programs / pɔ təb(ə)lprəυ r mz/ noun same as portable

software

portable software / pɔ təb(ə)lsɒftweə/ noun programs that can be run

on several different computer systems portal / pɔ t(ə)l/ noun a website that provides links to information and other websites

portrait / pɔ tr t/ adjective the orientation of a page or piece of paper in which

the longest edge is vertical

port replicator / pɔ t repl ke tə/ noun a version of a docking station that allows a laptop computer to be connected to duplicate the connection ports on the back of the laptop, allowing a user to keep a mouse, power cable, and printer connected to the port replicator and easily insert the laptop to use these ports without having to plug in cables each time the machine is

used

port selector /pɔ t s lektə/ noun a switch that allows the user to choose which peripheral a computer is connected

to, via its o/p port

port sharing /pɔ t ʃεər ŋ/ noun a device that is placed between one I/O port and a number of peripherals, allowing the computer access to all of them

POS /pɒz/ abbr point-of-sale positional /pə z ʃ(ə)nəl/ adjective re-

ferring to position

positioning time /pə z ʃ(ə)n ŋ ta m/ noun the amount of time required to access data stored in a disk drive or tape machine, including all mechanical movements of the read head and arm positive / pɒz t v/ adjective 1. meaning ‘yes’ 2. referring to an image that shows objects as they are seen 3. an electrical

voltage greater than zero

positive display / pɒz t v d sple / noun a display in which the text and graphics are shown as black on a white

background to imitate a printed page positive logic / pɒz t v lɒd' k/ noun

a logic system in which a logical one is represented by a positive voltage level, and

a logical zero represented by a zero or negative voltage level

positive photoresist / pɒz t vfəυtəυr z st/ noun a method of forming

photographic images where exposed areas of photoresist are removed, used in making PCBs

positive presentation / pɒz t vprez(ə)n te ʃ(ə)n/ noun a screen image

which is coloured on a white background positive response / pɒz t v r

spɒns/ noun a communication signal that

indicates correct reception of a message positive terminal / pɒz t v

t m n(ə)l/ noun a connection to a power supply source that is at a higher electrical potential than ground and supplies current to a component

POSIX / pɒs ks/ noun the IEEE standard that defines software that can be easily ported between hardware platforms. Full form portable operating system inter-

face

post /pəυst/ verb to enter data into a

record in a file

postbyte / pəυstba t/ noun in a program instruction, the data byte following the op code that defines the register to be

used

post-editing /pəυst ed t ŋ/ noun the process of editing and modifying text after it has been compiled or translated by a ma-

chine

post-filtering / pəυst f ltər ŋ/ noun image processing carried out after the im-

age has been compressed

postfix / pəυstf ks/ noun a word or let-

ter written after another

postfix notation / pəυstf ks nəυte ʃ(ə)n/ noun mathematical operations written in a logical way, so that the operator appears after the operands, which re-

moves the need for brackets post-formatted / pəυst fɔ m t d/

adjective referring to text arranged at

printing time rather than on screen posting / pəυst ŋ/ noun an online mes-

sage, especially a message sent to an Inter-

net newsgroup or bulletin board postmaster / pəυstmɑ stə/ noun the

email address of the person nominally in

charge of email within a company

post mortem /pəυst mɔ təm/ noun an examination of a computer program or piece of hardware after it has failed, designed to find out why the failure took place

post office / pəυst ɒf s/ noun the central store for the messages for users on a local area network

post office protocol /pəυst ɒf s/ noun POP 3

postprocessor / pəυst prəυsesə/ noun 1. a microprocessor that handles semi-processed data from another device 2. a program that processes data from another program, which has already been processed

post production / pəυst prə d kʃən/ noun the final editing process of a video or animation in which titles are added and sequences finalised

PostScript / pəυstskr pt/ a trade name for a standard page description language developed by Adobe Systems that offers flexible font sizing and positioning and is most often found in laser printers potential difference /pə tenʃəld f(ə)rəns/ noun the voltage difference between two points in a circuit

POTS /pɒts/ noun the simplest, standard telephone line without any special features such as call waiting or forwarding, and without high-speed digital access such as ADSL. Full form plain old telephone service

power / paυə/ noun 1. the unit of energy in electronics equal to the product of voltage and current, measured in watts 2. a mathematical term describing the number of times a number is to be multiplied by itself 5 to the power 2 is equal to 25.

(NOTE: written as small figures in superscript: 105: say: ‘ten to the power five’) verb to provide electrical or mechanical energy to a device The monitor is powered from a supply in the main PC.

PowerBook / paυəbυk/ a trade name for a laptop version of a Macintosh computer, designed by Apple Corp PowerCD / paυə si di / a trade name for a CD-ROM player produced by Apple that can connect to a television to display Photo CD images, or to a Macintosh as a standard CD-ROM drive, or to play back music CDs

power down / paυə daυn/ verb to turn off the electricity supply to a computer or other electronic device

power dump / paυə d mp/ verb to remove all power from a computer

power failure / paυə fe ljə/ noun the loss of the electric power supply

power loss / paυə lɒs/ noun the amount of power lost in transmission or through connection equipment

power management / paυəm n d'mənt/ noun software built into

laptop computers and some newer desktop PCs and monitors that, to save energy, will automatically turn off components that are

not being used

power monitor / paυə mɒn tə/ noun a circuit that shuts off the electricity supply if it is faulty or likely to damage equip-

ment

power-on reset / paυə ɒn ri set/ noun the automatic reset of a CPU to a known initial state immediately after pow-

er is applied

power on self test / paυə ɒn selftest/ noun a series of hardware tests that a computer carries out when it is first

switched on. Abbr POST

power pack / paυə p k/ noun a selfcontained box that will provide a voltage

and current supply for a circuit PowerPC / paυə pi si / a trade name

for a high-performance RISC-based proc-

essor developed by Motorola

power supply / paυə sə pla / noun a

PSU

power transient / paυə tr nziənt/ noun a very short duration voltage pulse or

spike

power up / paυə p/ verb to switch on

or apply a voltage to a electrical device power user / paυə ju zə/ noun a user

who needs the latest, fastest model of computer because he or she runs complex or demanding applications

ppm / pi pi em/ noun the number of pages that a printer can print in one minute, used for describing the speed of a printer. Full form pages per minute PPP / pi pi pi / noun a protocol that supports a network link over an asynchronous (modem) connection and is normally used to provide data transfer between a user’s computer and a remote server on the Internet using the TCP/IP network proto-

col. Full form point to point protocol

PPQN / pi pi kju en/ noun the most common time format used with standard MIDI sequences. Full form parts per

quarter note

PPTP / pi pi ti pi / noun a protocol that allows a standard local-area network protocol (such as Novell’s IPX or Microsoft’s NetBEUI) to be sent over the Inter-

net in a transparent manner without the user or operating system noticing, used by companies that want to use the Internet to connect servers in different offices. Full form point-to-point tunneling protocol

practical extraction and report language / pr kt k(ə)l k str kʃ(ə)n ən r pɔ t l ŋ w d'/ noun full form of

Perl

pre- /pri / prefix before

pre-agreed /pri ə ri d/ adjective which has been agreed in advance pre-allocation /pri lə ke ʃ(ə)n/ noun the execution of a process which does not begin until all memory and peripheral requirements are free for use pre-amplifier /pri mpl fa ə/ noun an electronic circuit which amplifies a signal to a particular level, before it is fed to an amplifier for output

precede /pr si d/ verb to come before something This instruction cancels the instruction which precedes it. precedence / pres d(ə)ns/ noun a set of computational rules defining the order in which mathematical operations are calculated

precise /pr sa s/ adjective very exact

The atomic clock will give the precise time of starting the process.

precision /pr s '(ə)n/ noun the fact that something is very accurate

precision of a number /pr s '(ə)n əv ə n mbə/ noun the number of digits in

a number

precompiled code /prikəm pa ldkəυd/ noun a code that is output from a compiler, ready to be executed precondition / pri kən d ʃ(ə)n/ verb to condition data before it is processed predefined / pri d fa nd/ adjective which has been defined in advance predicate / pred kət/ noun a function or statement used in rule-based programs such as expert systems

predictive /pr d kt v/ adjective using technology that works out which word a computer or mobile phone user is keying from its first few letters and automatically completes the word

pre-edit /pri ed t/ verb to change text before it is run through a machine to make sure it is compatible

preemptive multitasking /priempt v m ltitɑ sk ŋ/ noun a form of

multitasking in which the operating sys-

tem executes a program for a period of time, then passes control to the next program so preventing any one program using

all the processor time

pre-fetch /pri fetʃ/ noun CPU instructions stored in a short temporary queue before being processed, increasing the speed

of execution

prefetch unit /pri fetʃ ju n t/ noun part of a microprocessor that sorts out which instruction and data is next to be processed by looking in the main memory and the instruction cache and passing the

next instruction on to the decode unit pre-filtering /pri f ltər ŋ/ noun image

processing before the image is compressed (e.g., scaling the image)

prefix / pri f ks/ noun a code, instruction or character at the beginning of a mes-

sage or instruction

prefix notation / pri f ks nəυte ʃ(ə)n/ noun mathematical operations written in a logical way, so that the operator appears before the operands, removing the need for brackets

preformatted /pri fɔ m t d/ adjective which has been formatted already a preformatted disk

pre-imaging /pri m d' ŋ/ noun the process of generating one frame of an animation or video in a memory buffer before

it is transferred on screen for display preprinted stationery /pri pr nt d

ste ʃ(ə)n(ə)ri/ noun computer stationery which is preprinted with the company heading and form layout onto which the

details will be printed by the computer preprocess /pri prəυses/ verb to carry

out initial organisation and simple

processing of data

preprocessor /pri prəυsesə/ noun 1. software that partly processes or prepares data before it is compiled or translated 2. a small computer that carries out some initial processing of raw data before passing it to the main computer

‘…the C preprocessor is in the first stage of converting a written program into machine instructions the preprocessor can be directed to read in another file before completion, perhaps because the same information is needed in each module of the program’

[Personal Computer World]

preprogram /pri prəυ r m/ verb to

program a computer in advance preprogrammed /pri prəυ r md/

adjective referring to a chip that has been programmed in the factory to perform one function

prescan / pri sk n/ noun a feature of many flat-bed scanners that carry out a quick, low-resolution scan to allow you to re-position the original or mark the area that is to be scanned at a higher resolution

presentation graphics

/ prez(ə)nte ʃ(ə)n r f ks/ plural noun graphics used to represent business information or data

presentation layer / prez(ə)nte ʃ(ə)n le ə/ noun the sixth ISO/OSI standard network layer that agrees on formats, codes and requests for the start and end of a connection

Presentation Manager / prez(ə)nte ʃ(ə)n m n d'ə/ noun a graphical

user interface supplied with the OS/2 operating system

presentation software

/ prez(ə)nte ʃ(ə)n sɒftweə/ noun a software application that allows a user to create a business presentation with graphs, data, text and images

preset / pri set/ verb to set something in advance The printer was preset with new page parameters.

prestore /pri stɔ / verb to store data in memory before it is processed

presumptive address /pr z mpt v ə dres/ noun the initial address in a pro-

gram, used as a reference for others

presumptive instruction /prz mpt v n str kʃən/ noun an unmodi-

fied program instruction that is processed to obtain the instruction to be executed

pretty good privacy / pr ti υdpr vəsi/ noun full form of PGP

preventative /pr ventət v/, preventive /pr vent v/ adjective which tries to stop something happening

preventive maintenance /prvent v me ntənəns/ noun a regular in-

spection and cleaning of a system to prevent faults occurring

preview / pri vju / verb to display text or graphics on a screen as it will appear when it is printed out

previewer / pri vju ə/ noun a feature that allows a user to see on screen what a page will look like when printed The built-in previewer allows the user to check for mistakes.

PRI / pi ɑ a / noun a high-performance ISDN communications link that supports 23 separate B channels that can transfer 64Kbits/second plus one D channel for

signalling and control. Full form primary rate interface

primary / pra məri/ adjective first or ba-

sic or most important

primary channel / pra məritʃ n(ə)l/ noun a channel that carries the

data transmission between two devices primary key / pra məri ki / noun a

unique identifying word that selects one

entry from a database

primary memory / pra mərimem(ə)ri/ noun same as core memory

primary rate interface / pra məri re t ntəfe s/ noun full form of PRI

primary station / pra məri ste ʃ(ə)n/ noun the single station in a data network

that can select a path and transmit primary storage / pra məri stɔ r d'/

noun 1. a small fast-access internal memory of a system which contains the program currently being executed 2. the main internal memory of a system

prime /pra m/ adjective very important prime attribute / pra m ə tr bju t/

noun the most important feature or design of a system

primer / pra mə/ noun a manual or simple instruction book with instructions and examples to show how a new program or system operates

primitive / pr m t v/ noun 1. (in programming) a basic routine that can be used to create more complex routines 2. (in graphics) a simple shape such as circle, square, line or curve used to create more complex shapes in a graphics program print /pr nt/ noun characters made in ink on paper The print from the new printer is much clearer than that from old one. verb to put letters or figures in ink on paper printed agreement print out to print information stored in a computer with a printer

print control character /pr nt kəntrəυl/, print control code noun a spe-

cial character sent to a printer that directs it to perform an action or function, e.g. to

change font, rather than print a character printed circuit / pr nt d s k t/,

printed circuit board noun a flat insulating material that has conducting tracks of metal printed or etched onto its surface which complete a circuit when components are mounted on it. Abbr PCB printer / pr ntə/ noun a device that converts input data in an electrical form into a printed readable form. Abbr PRN

printer buffer / pr ntə b fə/ noun a temporary store for character data waiting to be printed, used to free the computer before the printing is completed making the operation faster

printer control characters / pr ntə kən trəυl k r ktəz/ noun a command

characters in a text which transmit printing commands to a printer

printer control language / pr ntə kən trəυl l ŋ w d'/ noun full form of

PCL

printer driver / pr ntə dra və/ noun dedicated software that converts and for-

mats users’ commands ready for a printer printer emulation / pr ntə emju

le ʃ(ə)n/ noun a printer that is able to interpret the standard set of commands used to control another brand of printer This printer emulation allows my NEC printer

to emulate an Epsom.

printer-plotter / pr ntə plɒtə/ noun a high-resolution printer that is able to mimic a plotter and produce low-resolution plots

printer port / pr ntə pɔ t/ noun the output port of a computer with a standard connector to which a printer is connected to

receive character data

printer quality / pr ntə kwɒl ti/ noun the standard of printed text from a particu-

lar printer

printer ribbon / pr ntə r bən/ noun a roll of inked material that passes between

a printhead and the paper

printer’s controller / pr ntəz kəntrəυlə/ noun the main device in a printer

that translates output from the computer

into printing instructions

print format /pr nt fɔ m t/ noun a way in which text is arranged when printed out, according to embedded codes, used to set features such as margins and headers print formatter / pr nt fɔ m tə/ noun a piece of software that converts embedded codes and print commands to printer

control signals

print hammer /pr nt h mə/ noun a moving arm in a daisy-wheel printer that presses the metal character form onto the

printer ribbon leaving a mark on the paper printhead / pr nthed/ noun 1. a row of

needles in a dot-matrix printer that produce characters as a series of dots 2. the metal form of a character that is pressed onto an inked ribbon to print the character on paper