Dictionary of Computing - 5th Edition

overscan / əυvəsk n/ noun 1. a faulty or badly adjusted monitor in which the displayed image runs off the edge of the screen 2. display equipment in which the picture beam scans past the screen boundaries to ensure that the image fills the screen

over-voltage protection / əυvəvəυlt d' prə tekʃ(ə)n/ noun a safety de-

vice that prevents a power supply voltage exceeding certain specified limits overwrite / əυvə ra t/ verb to write data to a location, e.g. memory or disk, and, in doing so, to destroy any data already contained in that location The latest data input has overwritten the old information.

(NOTE: overwriting – overwrote – overwritten)

p abbr pico-

P abbr peta

pack /p k/ noun a number of disks sold or kept together verb to store a quantity of data in a reduced form, often by representing several characters of data with one stored character

package deal / p k d' di l/ noun an agreement in which several different items are agreed at the same time They agreed a package deal, which involves the development of software, customising hardware

and training of staff.

packaged software / p k d'dsɒftweə/ noun same as software pack-

age

packed decimal /p kt des m(ə)l/ noun a sequence of decimal digits stored in a small space, by using only four bits for

each digit

packed format /p kt fɔ m t/ noun two binary coded decimal digits stored within one computer word or byte, usually achieved by removing the check or parity bit

packet / p k t/ noun a group of data bits which can be transmitted as a group from one node to another over a network

packet assembler/disassembler

/ p k t ə semblə d sə semblə/ noun a dedicated computer which converts serial data from asynchronous terminals to a form that can be transmitted along a pack-

et-switched, synchronous network. Abbr

PAD

packet Internet groper / p k tntənet rəυpə/ noun full form of PING

(see)

packet scheduler / p k t ʃedju lə/ noun a part of a network router that determines when to transmit the packet of data to the final destination based on the route that has been selected

packet switching / p k t sw tʃ ŋ/ noun a method of sending data across a WAN in small packets, which are then reassembled in the correct order at the receiving end

‘The network is based on Northern Telecom DPN data switches over which it will offer X.25 packet switching, IBM SNA, and frame-relay transmission.’ [Computing]

packet switching service / p k tsw tʃ ŋ s v s/ noun a commercial data transmission service that sends data over its WAN using packet switching. Abbr

PSS

packing / p k ŋ/ noun the process of putting large amounts of data into a small area of storage

packing density / p k ŋ dens ti/ noun the number of bits that can be stored in a unit area

packing routine / p k ŋ ru ti n/ noun a program which packs data into a small storage area

pad /p d/ noun a number of keys arranged together

PAD abbr packet assembler/disassembler

pad character /p d k r ktə/ noun an extra character added to a string or packet or file until it is a required size

padding / p d ŋ/ noun a character or set of digits added to fill out a string or packet until it is the right length

paddle / p d(ə)l/ noun a computer peripheral consisting of a knob or device which is turned to move a cursor or pointer on the screen

page /pe d'/ noun 1. a sheet of paper 2. an amount of text displayed on a computer monitor or screen which would fill a page of paper if printed out or which fills the screen 3. a section of main store, which contains data or programs 4. one section of a main program which can be loaded into main memory when required verb 1. to make up a text into pages 2. to divide computer backing store into sections to allow long programs to be executed in a small main memory (NOTE: pages – paging – paged)

page addressing /pe d' ə dres ŋ/ noun main memory which has been split into blocks, with a unique address allocated to each block of memory which can then be called up and accessed individually, when required

page boundary /pe d' baυnd(ə)ri/ noun a point where one page ends and the next starts

page break / pe d' bre k/ noun 1. the point in continuous text at which a page ends and a new page starts 2. a marker used when word-processing to show where a new page should start

paged address / pe d'd ə dres/ noun

(in a paged-memory scheme) the actual physical memory address that is calculated from a logical address and its page address

page description language / pe d' d skr pʃən l ŋ w d'/ noun software

that controls a printer’s actions to print a page of text to a particular format according to a user’s instructions. Abbr PDL

page description programming language /pe d' d skr pʃ(ə)nprəυ r m ŋ l ŋ w d'/ noun a pro-

gramming language that accepts commands to define the size, position and type style for text or graphics on a page

page display /pe d' d sple / noun the process of showing a page of text on the screen as it will appear when printed out

paged-memory management unit

/ pe d'd mem(ə)ri m n d'məntju n t/ noun an electronic logic circuit that manages the translation between logical addresses that refer to a particular page and the real physical address that is being referenced

paged-memory scheme / pe d'dmem(ə)ri ski m/ noun a way of dividing

memory into areas or pages which are then allocated a page number (NOTE: Memory addresses are relative to a page that is then mapped to the real, physical memory. This system is normally used to imple-

ment virtual memory.)

page down key / pe d' daυn ki / noun a keyboard key that moves the cursor position down by the number of lines on

one screen. Abbr PgDn

page frame / pe d' fre m/ noun a physical address to which a page of virtual

or logical memory can be mapped

page image buffer / pe d' m d'b fə/ noun memory in a page printer that holds the image as it is built up before it is

printed

page impression /pe d' m preʃ(ə)n/ noun a measure used to count how many times a webpage has been displayed to a

visitor to a website

page layout /pe d' le aυt/ noun the arrangement of text and pictures within a page of a document We do all our page

layout using desktop publishing software. page length / pe d' leŋθ/ noun the

length of a page in word-processing page makeup / pe d' me k p/ noun

the action of pasting images and text into a

page ready for printing

page-mode RAM / pe d' məυd r m/ noun dynamic RAM designed to access sequential memory locations very quickly

The video adapter uses page-mode RAM

to speed up the display.

page number /pe d' n mbə/ noun a unique number assigned to each page within a multimedia application, to be used within hyperlinks and when moving between pages

page orientation /pe d' ɔ riənte ʃ(ə)n/ noun the direction of the long

edge of a piece of paper

page preview /pe d' pri vju / noun

(in WP or DTP software) a graphical rep-

resentation of how a page will look when printed, with different type styles, margins

and graphics correctly displayed

page printer /pe d' pr ntə/ noun a printer, usually a laser printer, which composes one page of text within memory and

then prints it in one pass

page protection /pe d' prə tekʃən/ noun the set of software controls used to ensure that pages are not overwritten by accident or copied into a reserved section

of memory

page reader /pe d' ri də/ noun a device which converts written or typed information to a form that a computer can un-

derstand and process

page requests /pe d' r kwestz/ plural noun a measure of the number of pages viewed in a day, providing an indication of

the popularity of your website

page setup / pe d' set p/ noun the set of software options that allow a user to set up how the page will look when printed, – usually setting the margins, size of

paper, and scaling of a page

pages per minute / pe d' z pm nət/ noun full form of ppm This la-

ser printer can output eight pages per

minute.

page table /pe d' te b(ə)l/ noun a list of all the pages and their locations within main memory, used by the operating sys-

tem when accessing a page

page up key / pe d' p ki / noun a keyboard key that moves the cursor position up by the number of lines in one

screen. Abbr PgUp

page width / pe d' , w dθ/ noun the number of characters across a page or line pagination / p d' ne ʃ(ə)n/ noun the process of dividing text into pages paging / pe d' ŋ/ noun a virtual memory technique of splitting main memory into small blocks or pages which are allocated an address and which can be called up when required

COMMENT: A virtual memory management system stores data as pages in memory to provide an apparently larger capacity main memory by storing unused pages in backing store, copying them into main memory only when required.

paging algorithm / pe d' ŋ

l ər ð(ə)m/ noun a formula by which the memory management allocates memory to pages, also covering the transfer from backing storage to main memory in the most efficient way

paint /pe nt/ noun (in a graphics program) colour and pattern used to fill an area verb (in a graphics program) to fill an enclosed graphics shape with a colour

Paintbrush/Paint / pa ntbr ʃ pe nt/ noun an application supplied with Microsoft Windows 3.1x and Windows 95 for creating or editing bitmap images

paint object / pe nt ɒbd'ekt/ noun a bitmap image

paint program / pe nt prəυ r m/ noun software that allows a user to draw pictures on screen in different colours, with different styles of brush and special effects I drew a rough of our new logo with this paint program.

COMMENT: Paint programs normally operate on bitmap images. Drafting or design software normally works with vector-based images.

paired register / peəd red' stə/ noun a set of two basic word size registers used together as one large word size register, often for storing address words The 8-bit CPU uses a paired register to provide a 16-bit address register.

PAL / pi e el/ noun a standard for television transmission and reception using a 625-line picture transmitted at 25 frames per second. Full form phase alternation line (NOTE: PAL provides a clearer image than NTSC and is used in most of Europe, except for France, which uses SECAM. The USA and Japan use NTSC.) palette / p lət/ noun the range of colours which can be used on a printer or computer display

palette shift / p lət ʃ ft/ noun an image displayed using the wrong palette with the unwanted effect that the colours appear distorted

palmtop / pɑ mtɒp/ noun a personal computer that is small enough to be held in one hand and operated with the other

This palmtop has a tiny keyboard and twenty-line LCD screen.

pan /p n/ verb 1. (in computer graphics) to smoothly move a viewing window horizontally across an image that is too wide to display all at once 2. (in MIDI or sound) to adjust the balance of a sound between the two stereo channels (NOTE: panning – panned)

panel / p n(ə)l/ noun a flat section of a casing with control knobs or sockets The socket is on the back panel.

Pantone Matching System

/ p ntəυn m tʃ ŋ s stəm/ a trade

name for a standard method of matching ink colours on screen and on printed output using a book of pre-defined colours. Abbr PMS

paper-fed / pe pə fed/ adjective referring to a device which is activated when paper is introduced into it a paper-fed

scanner

paper feed / pe pə fi d/ noun a mechanism which pulls paper through a printer paperless / pe pələs/ adjective without

using paper

paperless office / pe pələs ɒf s/ noun an office which uses computers and other electronic devices for office tasks and avoids the use of paper

‘Indeed, the concept of the paperless office may have been a direct attack on Xerox and its close ties to the paper document. Yet, as we all know, the paperless office has so far been an empty promise.’ [Comput-

ing]

paper tape / pe pə te p/ noun a long strip of paper on which data can be record-

ed, usually in the form of punched holes paper tape feed / pe pə te p fi d/

noun a method by which paper tape is

passed into a machine

paper tape punch / pe pə te pp ntʃ/ noun a device which punches

holes in paper tape to carry data

paper tape reader / pe pə te pri də/ noun a device which accepts punched paper tape and converts the punched information stored on it into sig-

nals which a computer can process paper throw / pe pə θrəυ/ noun rapid

vertical movement of paper in a printer paper tray / pe pə tre / noun a container used to hold paper to be fed into a print-

er

paper-white monitor / pe pə wa tmɒn tə/ noun a monitor that normally displays black text on a white background, rather than the normal illuminated text on a black background

paragraph / p rə rɑ f/ noun 1. (in a document) the section of text between two carriage return characters, with a unified subject 2. (in a memory map) a 16-byte section of memory which starts at a hexadecimal address that can be evenly divided by 16

paragraph marker / p rə rɑ fmɑ kə/ noun (in a document) a nonprinting character that shows where a carriage return is within a document

parallel / p rəlel/ adjective 1. referring to a computer system in which two or

more processors operate simultaneously on one or more items of data 2. referring to two or more bits of a word transmitted over separate lines at the same time parallel access / p rəlel kses/ noun data transfer between two devices with a number of bits, usually one byte wide, being sent simultaneously parallel adder / p rəlel də/ noun a number of adders joined together, allowing several digits to be added at once parallel broadcast / p rəlelbrɔ dkɑ st/ noun a broadcast that is transmitted simultaneously by radio or television and over the Internet

parallel computer / p rəlel kəmpju tə/ noun a computer with one or more logic or arithmetic units, allowing parallel processing

parallel connection / p rəlel kənekʃ(ə)n/ noun a connector on a computer allowing parallel data to be transferred

Their transmission rate is 60,000 bps through parallel connection.

parallel data transmission

/ p rəlel de tə tr nz m ʃ(ə)n/ noun the transmission of bits of data simultaneously along a number of data lines

parallel input/output / p rəlelnpυt aυtpυt/ noun full form of PIO

parallel input/output chip / p rəlelnpυt aυtpυt tʃ p/ noun a dedicated in-

tegrated circuit that performs all handshaking, buffering and other operations needed when transferring parallel data to and from a CPU

parallel input/parallel output

/ p rəlel npυt p rəlel aυtpυt/ noun full form of PIPO

parallel input/serial output

/ p rəlel npυt s əriəl aυtpυt/ noun full form of PISO

parallel interface / p rəlel ntəfe s/ noun a circuit and connector that allows parallel data to be received or transmitted. Also called parallel port

parallel operation / p rəlel ɒpəre ʃ(ə)n/ noun a number of processes carried out simultaneously on a number of inputs

parallel printer / p rəlel pr ntə/ noun a printer that is connected to a computer via a parallel interface and accepts character data in parallel form

‘The Wheelwriter 7000 offers 172Kb of document storage and mail-merge capabilities: it can be con-

nected to a PC using the parallel printer port.’ [Computing]

parallel priority system / p rəlel pra ɒr ti s stəm/ noun a number of pe-

ripherals connected in parallel to one bus, which, if they require attention, send their address and an interrupt signal, which is then processed by the computer according to device priority

parallel processing / p rəlelprəυses ŋ/ noun computer operation on

several tasks simultaneously

parallel running / p rəlel r n ŋ/ noun the running of an old and a new computer system together to allow the new system to be checked before it becomes the only system used

parallel search storage / p rəlels tʃ stɔ r d'/ noun data retrieval from storage that uses part of the data other than an address to locate the data

parallel transfer / p rəlel tr nsf / noun data transfer between two devices with a number of bits, usually one byte wide, being sent simultaneously parallel transmission / p rəlel tr nz m ʃ(ə)n/ noun data transmitted over a number of data lines carrying all the bits of a data word simultaneously. Compare serial transmission

parameter /pə r m tə/ noun an item of information which defines the limits or actions of something, e.g. a variable, routine or program The X parameter defines the number of characters displayed across a screen.

parameter-driven software /pər m tə dr v(ə)n sɒftweə/ noun soft-

ware whose main functions can be modified and tailored to a user’s needs by a number of variables parameterisation /pə r m təraze ʃ(ə)n/, parameterization noun the action of setting parameters for software

parameter passing /pə r m təpɑ s ŋ/ noun (in a program) a value passed to a routine or program when it is called

parameter testing /pə r m tətest ŋ/ noun the process of using a pro-

gram to examine the parameters and set up the system or program accordingly parameter word /pə r m tə w d/ noun a data word that contains information defining the limits or actions of a routine or program

parametric equaliser / p rəmetr ki kwəla zə/ noun a device that can en-

hance or reduce the levels of particular frequencies within an audio signal

parametric subroutine

/ p rəmetr k s bru ti n/ noun a subroutine that uses parameters to define its

limits or actions

parent directory / peərənt darekt(ə)ri/ noun (in a DOS filing system)

the directory above a subdirectory parent folder / peərənt fəυldə/ noun

(in an Apple Mac filing system) one folder

that contains other folders

parent object / peərənt ɒbd'ekt/ noun a page that contains the object that is

being referenced

parent program / peərəntprəυ r m/ noun a program that starts another program, a child program, while it is still running (NOTE: Control passes back to the parent program when the child program has finished.)

parity / p r ti/ noun the fact of being equal

‘The difference between them is that RAID level one offers mirroring, whereas level five stripes records in parity across the disks in the system.’ [Computing] parity bit / p r ti b t/ noun an extra bit added to a data word as a parity checking

device

parity check / p r ti tʃek/ noun a method of checking for errors and that transmitted binary data has not been corrupted by adding an extra bit

parity flag / p r ti fl / noun an indicator that shows if data has passed a parity

check or if data has odd or even parity parity interrupt / p r ti ntər pt/

noun an interrupt signal from an error checking routine which indicates that received data has failed a parity check and is

corrupt

parity track / p r ti tr k/ noun a track on magnetic or paper tape that carries the parity bit

park /pɑ k/ verb to move the read/write head of a hard disk drive over a point on the disk where no data is stored When parked, the disk head will not damage any data if it touches the disk surface.

parse /pɑ z/ verb to break down highlevel language code into its element parts when translating into machine code (NOTE: parses – parsing – parsed)

parser / pɑ zə/ noun a program that parses computer input (NOTE: Using the

grammar of the language involved, it works out how a sentence can be constructed from the input and produces a parse tree to show this.)

part /pɑ t/ noun a section of something part exchange / pɑ t ks tʃe nd'/ noun the act of giving an old product as part of the payment for a new one partial carry / pɑ ʃ(ə)l k ri/ noun temporary storage of all carries generated by parallel adders rather than a direct transfer

partial RAM / pɑ ʃ(ə)l r m/ noun a RAM chip in which only a certain area of the chip functions correctly, usually in newly released chips (NOTE: Partial RAMs can be used by employing more than one to make up the capacity of one fully functional chip.)

partition /pɑ t ʃ(ə)n/ noun 1. an area of a hard disk that is treated as a logical drive and can be accessed as a separate drive I defined two partitions on this hard disk – called drive C: and D:. 2. a section of computer memory set aside as foreground or background memory verb 1. to divide a hard disk into two or more logical drives that can be accessed as separate drives 2. to divide a large file or block into several smaller units which can be accessed and handled more easily partitioned file /pɑ t ʃ(ə)nd fa l/ noun one file made up of several smaller sequential files, each part of which can be accessed individually by the control program

part page display / pɑ t pe d' dsple / noun a display of only a section of a page, and not the whole page

parts per quarter note / pɑ ts pkɔ tə nəυt/ noun full form of PPQN

PASCAL / p sk l/ noun a high-level structured programming language used both on micros and for teaching programming

pass /pɑ s/ noun 1. the execution of a loop, once 2. a single operation 3. the action of moving the whole length of a magnetic tape over the read/write heads password / pɑ s w d/ noun a word or series of characters which identifies a user so that he or she can access a system

‘…the system’s security features let you divide the disk into up to 256 password-protected sections’

[Byte]

password protection / pɑ sw d prətekʃ(ə)n/ noun a computer software that

requires the user to enter a password before he or she can gain access

paste /pe st/ verb to insert text or graphics that has been copied or cut into a file

Now that I have cut this paragraph from the end of the document, I can paste it in here. (NOTE: pastes – pasting – pasted)

Paste Special / pe st speʃ(ə)l/ noun a facility for inserting a special object such as sound, images or data from other applications into a document

patch /p tʃ/ noun a temporary correction made to a program by a user, often on the instructions of the software publisher patch cord / p tʃ kɔ d/ noun a short cable with a connector at each end, used to make an electrical connection on a patch panel

patch panel /p tʃ p n(ə)l/ noun a set of electrical terminals that can be interconnected using short patch cords, allowing quick and simple reconfiguration of a network

path /pɑ θ/ noun 1. a possible route or sequence of events or instructions within the execution of a program 2. a route from one point in a communications network to another 3. (in the DOS operating system) a list of subdirectories in which the operating system should look for a named file

You cannot run the program from the root directory until its directory is added to the path.

pathname / pɑ θ ne m/ noun the location of a file with a listing of the subdirectories leading to it The pathname for the letter file is .DOC.

pattern / p t(ə)n/ noun a series of regular lines or shapes which are repeated again and again

patterned / p t(ə)nd/ adjective with patterns

pattern palette / p t(ə)n p lət/ noun a range of predefined patterns that can be used to fill an area of an image

pattern recognition / p t(ə)n rekən ʃ(ə)n/ noun algorithms or program functions that can identify a shape, e.g. from a video camera

pause key / pɔ z ki / noun a keyboard key that temporarily stops a process, often a scrolling screen display, until the key is pressed a second time

payment gateway / pe mənte twe / noun a server or organisation that acts as an interface between the pay-

ment systems of the seller and the buyer when payments are made over the Internet

payment gateway certificate authority / pe mənt e twe sə t f kət

ɔ θɒr ti/ noun an organisation that issues, renews or cancels the certificates that identify an Internet payment gateway. Abbr PGCA

PB abbr petabyte

PBX abbr private branch exchange

PC / pi si / noun a computer that uses an Intel 80x86 processor and is based on the IBM PC-style architecture. Full form personal computer (NOTE: PC originally referred to a microcomputer specification with an 8086-based low-power computer.)

PC-97 noun the set of basic requirements for the hardware of a PC system that can run the Windows 95 operating system PC-98 noun the set of basic requirements for the hardware of a PC system that can

run the Windows 98 operating system PC/AT / pi si e ti / noun a PC-com-

patible computer that used an Intel 80286 processor and was fitted with 16-bit ISA

expansion connectors

PC/AT keyboard / pi si e tiki bɔ d/ noun a keyboard that features 12 function keys arranged in one row along the top of the keyboard

PCB abbr printed circuit board

PC Card / pi si kɑ d/ noun an electronic device, about the same size as a thick credit card, that can be plugged into a PCMCIA adapter to provide a particular function. PCMCIA (NOTE: For example, PC Cards are available that provide a modem, NIC, extra memory and hard

disk drive functions.)

PC-compatible / pi si kəmp təb(ə)l/ adjective referring to a com-

puter that is compatible with the IBM PC PC-DOS / pi si dɒs/ noun a version of

MS-DOS that is sold by IBM

p-channel metal oxide semiconductor /pi tʃ n(ə)l met(ə)l ɒksa dsemikən d ktə/ noun full form of

PMOS

PCI / pi si e / noun a specification produced by Intel defining a type of fast local bus that allows high-speed data transfer between the processor and expansion cards. Full form peripheral component interconnect

PCL / pi si el/ noun standard set of commands, defined by Hewlett Packard,

that allow a computer to control a printer. Full form printer control language

PCM / pi si em/ noun 1. a company that produces add-on boards which are compatible with another manufacturer’s computer. Full form plug-compatible manufacturer 2. a way of storing sounds in an accurate, compact format that is used by high-end sound cards. Full form pulsecode modulation

PCMCIA / pi si em si a e / noun a specification for add-in expansion cards that are the size of a credit card with a connector at one end The extra memory is stored on this PCMCIA card and I use it on my laptop. Full form Personal Computer Memory Card International Association

PCMCIA card / pi si em si a e kɑ d/ noun add-in memory or a peripheral which complies with the PCMCIA standard

PCMCIA connector / pi si em si a e kə nektə/ noun a 68-pin connector

that is inside a PCMCIA slot and on the end of a PCMCIA card

PCMCIA slot / pi si em si a e slɒt/ noun an expansion slot, normally on a laptop, that can accept a PCMCIA expansion card

P-code /pi kəυd/ noun an intermediate code produced by a compiler that is ready for an interpreter to process, usually for PASCAL programs

PCS abbr personal communications services

PC/TV / pi si ti vi / noun a personal computer that can receive, decode and display standard television images

PCU / pi si ju / noun a device used to convert input and output signals and instructions to a form that a peripheral device will understand. Full form peripheral control unit

PCX file / pi si eks fa l/ noun a method of storing a bitmap graphic image file on disk

PC/XT / pi si eks ti / noun a PC-com- patible computer that was fitted with a hard disk drive and used a 8086 Intel processor

PC/XT keyboard / pi si eks tiki bɔ d/ noun a keyboard that features 10 function keys arranged in two columns along the left hand side of the keyboard

PD abbr public domain

PDA / pi di e / noun a lightweight palmtop computer that provides the basic functions of a diary, notepad, addressbook and to-do list together with fax or modem communications. Full form personal digital assistant (NOTE: Current PDA designs do not have a keyboard, but use a touch-sensitive screen with a pen and handwriting-recognition to control the software.)

PDF / pi di ef/ noun a file format used by Adobe Acrobat. Full form portable document format

PDL abbr 1. page description language 2. program design language

PDN abbr public data network

peak /pi k/ noun the highest point verb

to reach the highest point

peak output /pi k aυtpυt/ noun the

highest output

peak period / pi k p əriəd/ noun the time of the day when most power is being used

peek /pi k/ noun a BASIC computer instruction that allows the user to read the contents of a memory location You need the instruction PEEK 1452 here to examine the contents of memory location 1452.

Compare poke

peer /p ə/ noun each of two similar devices operating on the same network protocol level

peer-to-peer network / p ə tə p ə/ noun a local area network, usually using NICs in each computer, that does not use a central dedicated server, but instead each computer in the network shares the jobs

We have linked the four PCs in our small office using a peer-to-peer network.

pel /pel/ noun same as pixel

pen /pen/ noun same as light pen

pen computer /pen kəm pju tə/ noun a type of computer that uses a light pen instead of a keyboard for input (NOTE: The computer has a touch-sensitive screen and uses handwriting-recognition software to interpret the commands written

on the screen using the light pen.)

pen plotter / pen plɒtə/ noun a plotter that uses removable pens to draw an image

on paper

pen recorder /pen r kɔ də/ noun a peripheral which moves a pen over paper ac-

cording to an input

Pentium / pentiəm/ a trade name for a range of electronic processor components developed by Intel (NOTE: They are back-

wards-compatible with the 80x86 family used in IBM PCs. The processor uses a 32-bit address bus and a 64-bit data bus.)

per as per according to noun 1. at a rate of 2. out of or for each The rate of imperfect items is about 25 per 1.000. per cent /pə sent/ adjective, adverb out of each hundred or for each hundred 10 per cent ten in every hundred what is the increase per cent? fifty per cent of

nothing is still nothing

percentage point /pə sent d' pɔ nt/ noun one per cent

percentile /pə sen ta l/ noun one of a series of 99 figures below which a certain percentage of the total falls

per day /pə de / phrase for each day perforated tape / p fə re t d te p/

noun a paper tape or long strip of tape on which data can be recorded in the form of punched holes

perforation / p fə re ʃ(ə)n/ noun any one of a line of very small holes in a sheet of paper or continuous stationery, to help

when tearing

perforator / p fəre tə/ noun a machine that punches holes in a paper tape perform /pə fɔ m/ verb to do well or badly

performance /pə fɔ məns/ noun the way in which someone or something works

per hour / pər aυə/ adverb for each

hour

period / p əriəd/ noun 1. a length of time for a period of time or for a period of months or for a six-year period 2. a printing sign used at the end of a piece of

text, the full stop

periodic / p əri ɒd k/, periodical

/ p əri ɒd k(ə)l/ adjective 1. happening from time to time a periodic review of the company’s performance 2. referring to a signal or event that occurs regularly

The clock signal is periodic. periodically / p əri ɒd kli/ adverb

from time to time

peripheral /pə r f(ə)rəl/ adjective which is not essential noun 1. an item of hardware such as a terminals, printers or monitors which is attached to a main computer system Peripherals such as disk drives or printers allow data transfer and are controlled by a system, but contain independent circuits for their operation.

Also called peripheral unit 2. any device

that allows communication between a system and itself but is not directly operated by the system

peripheral component interconnect /pə r f(ə)rəl kəm pəυnəntntəkənekt/ noun full form of PCI

peripheral control unit /pə r f(ə)rəl kən trəυl ju n t/ noun full form of PCU

peripheral driver /pə r f(ə)rəldra və/ noun a program or routine used to interface, manage and control an input/output device or peripheral

peripheral equipment /pə r f(ə)rəlkw pmənt/ noun 1. external devices that

are used with a computer, e.g. a printer or scanner 2. communications equipment external to a central processor that provides extra features

peripheral interface adapter /pər f(ə)rəl ntəfe s ə d ptə/ noun full

form of PIA

peripheral limited /pə r f(ə)rəll m t d/ noun a CPU that cannot execute instructions at normal speed because of a slow peripheral

peripheral memory /pə r f(ə)rəlmem(ə)ri/ noun storage capacity available in a peripheral

peripheral processing unit /pər f(ə)rəl prəυses ŋ ju n t/ noun a de-

vice used for input, output or storage which is controlled by the CPU. Abbr

PPU

peripheral software driver /pər f(ə)rəl sɒftweə dra və/ noun a short

section of computer program that allows a user to access and control a peripheral easily

peripheral transfer /pə r f(ə)rəltr nsf / noun the movement of data between a CPU and peripheral peripheral unit /pə r f(ə)rəl ju n t/ noun 1. an item of hardware such as a terminal, printer or monitor which is attached to a main computer system. Also called peripheral 2. any device that allows communication between a system and itself, but is not operated only by the system

Perl /p l/ noun an interpreted programming language, usually used under Unix, used to create CGI scripts that can process forms or carry out functions on a web server to enhance a website. Full form practical extraction and report language

permanent dynamic memory

/ p mənənt da n m k mem(ə)ri/

noun a storage medium which retains data

even when power is removed permanent error / p mənənt erə/

noun an error in a system which cannot be

repaired

permanent file / p mənənt fa l/ noun a data file that is stored in a backing storage device such as a disk drive permanent memory / p mənəntmem(ə)ri/ noun a computer memory that

retains data even when power is removed

permanent swap file / p mənəntswɒp fa l/ noun a file on a hard disk,

made up of contiguous disk sectors, which stores a swap file for software that implements virtual memory, e.g. Microsoft Windows

permission /pə m ʃ(ə)n/ noun authorisation given to a particular user to access a certain shared resource or area of disk

This user cannot access the file on the server because he does not have permis-

sion.

permutation / p mjυ te ʃ(ə)n/ noun each of a number of different ways in which something can be arranged The cipher system is very secure since there are so many possible permutations for the

key.

persistence /pə s stəns/ noun the length of time that a CRT will continue to display an image after the picture beam has stopped tracing it on the screen Slow scan rate monitors need long persistence phosphor to prevent the image flickering.

personal communications services / p s(ə)n(ə)l kə mju n ke ʃ(ə)nz

s v s z/ plural noun a range of wireless communication systems that allow computers to exchange data with other devices

such as a printer or PDA. Abbr PCS

personal computer / p s(ə)n(ə)l kəm pju tə/ noun full form of PC

Personal Computer Memory Card

International Association

/ p s(ə)nəl kəm pju tə mem(ə)ri kɑ dntən ʃ(ə)nəl ə səυsi e ʃ(ə)n/ noun

full form of PCMCIA (see)

personal digital assistant

/ p s(ə)n(ə)l d d' t(ə)l ə s stənt/ noun full form of PDA

personal identification device

/ p s(ə)n(ə)l a dent f ke ʃ(ə)n dva s/ noun full form of PID

personal identification number

/ p s(ə)n(ə)l a dent f ke ʃ(ə)nn mbə/ noun full form of PIN

personal information manager

/ p s(ə)n(ə)l nfə me ʃ(ə)n m n d'ə/

noun full form of PIM

personalise / p s(ə)nəla z/, personalize verb to customise or adapt a product specially for a certain user (NOTE: personalises – personalising – personalised) personalising, personalizing noun the process of changing the settings of Windows from their default

COMMENT: For example, you can change the background wallpaper to display a different image behind your windows or you could change the colours of the title bars, the font used by Windows and so on. To make these changes, use the Start/Settings menu item in Windows or the Control Panel icon in the Main

program group of Windows 3.1x.

perspective /pə spekt v/ noun the appearance of depth in an image in which objects that are further away from the viewer appear smaller

perspective correction /pə spekt v kə rekʃ(ə)n/ noun (in a three-dimension-

al scene) a method that is used to change the size and shape of an object to give the impression of depth and distance

PERT /p t/ noun a definition of tasks or jobs and the time each requires, arranged in order to achieve a goal. Full form program evaluation and review technique per week /pə wi k/ adverb for each week

per year /pə j ə/ adverb for each year peta /petə/ prefix one quadrillion (250).

Abbr P

petabyte / petəba t/ noun one quadrillion bytes. Abbr PB

PGCA abbr Payment Gateway Certifi-

cate Authority

PgDn / pe d' daυn/ abbr page down key

PGP / pi d'i pi / noun an encryption system developed to allow anyone to protect the contents of his or her email messages from unauthorised readers. Full form pretty good privacy (NOTE: This system is often used when sending credit card or payment details over the Internet.)

PgUp / pe d' p/ abbr page up key phantom ROM / f ntəm rɒm/ noun a

duplicate area of read-only memory that is accessed by a special code

phase /fe z/ noun one part of a larger process verb to phase in, to phase out to introduce something gradually or to reduce something gradually

phase alternation line / fe z ɔ ltəne ʃ(ə)n la n/ noun full form of PAL

phased change-over / fe zdtʃe nd'/ noun gradually introduction of a new device as the old one is used less and less

PHIGS /f z/ noun a standard application interface between software and a graphics adapter that uses a set of standard commands to draw and manipulate 2D and 3D images. Full form programmer’s hierarchical interactive graphics standard

phone /fəυn/ noun a telephone or machine used for speaking to someone over a long distance We had a new phone system installed last week.

Phone Dialer / fəυn da ələ/ noun same as Dialer

phoneme / fəυni m/ noun one small meaningful sound, several of which may make up a spoken word (NOTE: Phonemes are relevant to the analysis of voice input to recognise words and in the reproduction of speech.)

phone number / fəυn n mbə/ noun a set of figures for a particular telephone

He keeps a list of phone numbers in a little black book.

Phong shading / fɒŋ ʃe d ŋ/ noun the most complex method of applying shading to a three-dimensional scene that creates the smoothest shading effects and is better than a Gouraud shading (NOTE: The disadvantage is that this method is very processor-intensive and so takes a long time to process each scene.) phosphor / fɒfsə/ noun a substance that produces light when excited by some form of energy, usually an electron beam, used for coating the inside of a cathode ray tube

COMMENT: A thin layer of phosphor is arranged in a pattern of small dots on the inside of a television screen which produces an im-

age when scanned by the picture beam.

phosphor coating / fɒsfə kəυt ŋ/ noun a thin layer of phosphor on the inside of a CRT screen

phosphor dots / fɒsfə dɒtz/ plural noun individual dots of red, green and blue phosphor on a colour CRT screen phosphor efficiency / fɒsfəf ʃ(ə)nsi/ noun a measure of the amount of light produced in ratio to the energy received from an electron beam phosphor triad / fɒsfə tra d/ noun a group of three individual phosphor dots,