piracy ~ preventive maintenance
A/B Switch box ~ America On-line AMI BIOS ~ Arithmetic Operation ARP ~ AVI Backbone ~ Bit Image Bit Map ~ Boot Disk Boot Drive ~ Bytes Per Inch C++ ~ Carrier Frequency carrier system ~ certification CGI ~ Chooser extension cipher ~ Clipper Chip clock ~ color color bits ~ communications satellite communications server ~ computer security CON ~ copy copy program ~ cycle time daemon ~ defragmentation demand paging ~ digitize DikuMUD ~ disk disk buffer ~ Document Style Semantics and Specification Language document window ~ dynamic Web page Easter egg ~ erase erase head ~ ezine F2F ~ finger2 firewall ~ font suitcase footer ~ FYI Game Control Adapter ~ GUI HAL ~ hot key1 hot key2 ~ Hz i486DX ~ internal modem internet ~ ISO 9660 ISO/OSI model ~ just-in-time K1 ~ knowledge base L1 cache ~ LU luggable computer ~ LZW compression MAC ~ MILNET mime ~ msec MTBF ~ MYOB named anchor ~ network drive Network File System ~ number crunching object ~ overwrite mode P5 ~ PC/XT keyboard PDA ~ pipeline processing piracy ~ preventive maintenance preview ~ pwd quasi-language ~ QWERTY keyboard R&D ~ registration marks Registry ~ RFI RF shielding ~ run-time library SAA ~ server error server push-pull ~ soft return software ~ style sheet stylus ~ System T1 ~ ToggleKeys token ~ typography UART ~ uupc V.120 ~ view2 viewer ~ VxD w3 ~ WinG WINS ~ WWW X.25 ~ X Windows Yahoo! ~ yotta- Z39.50 standard ~ Zulu time
piracy
n. 1. The theft of a computer design or program. 2. Unauthorized distribution and use of a computer program.
pixel
n. Short for picture (pix) element. One spot in a rectilinear grid of thousands of such spots that are individually "painted" to form an image produced on the screen by a computer or on paper by a printer. A pixel is the smallest element that display or print hardware and software can manipulate in creating letters, numbers, or graphics. Also called pel.
pixel image
n. The representation of a color graphic in a computer's memory. A pixel image is similar to a bit image, which also describes a screen graphic, but a pixel image has an added dimension, sometimes called depth, that describes the number of bits in memory assigned to each on-screen pixel.
pixel map
n. A data structure that describes the pixel image of a graphic, including such features as color, image, resolution, dimensions, storage format, and number of bits used to describe each pixel. See also pixel, pixel image.
PKUNZIP
n. A shareware utility program that uncompresses files compressed by the PKZIP shareware utility program. PKUNZIP is generally made available with PKZIP; distribution of PKUNZIP for commercial purposes is not permitted without permission from its publisher, PKware, Inc. See also PKZIP.
PKZIP
n. A widely used shareware utility program for compressing files. Developed by PKware, Inc., in 1989 and available from a wide variety of sources, PKZIP can combine one or more files into a compressed output file having the extension .zip. A companion utility program, PKUNZIP, is required to uncompress the compressed files. See also PKUNZIP, shareware, utility program.
PLA
n. Acronym for programmable logic array. See field-programmable logic array.
plaintext
n. 1. Nonencrypted or decrypted text. See also decryption, encryption. 2. A file that is stored as plain ASCII data.
plain vanilla
adj. Ordinary; the standard version of hardware or software without any enhancements. For example, a plain vanilla modem might have data transfer capability but no fax or voice features.
platform
n. 1. The foundation technology of a computer system. Because computers are layered devices composed of a chip-level hardware layer, a firmware and operating-system layer, and an applications program layer, the bottommost layer of a machine is often called a platform. 2. In everyday usage, the type of computer or operating system being used.
platter
n. One of the individual metal data storage disks within a hard disk drive. Most hard disks have from two to eight platters. See also hard disk.
PL/C
n. A version of the PL/I programming language developed at Cornell University and used on mainframe computers. See also PL/I.
plot
vb. To create a graphic or a diagram by connecting points representing variables (values) that are defined by their positions in relation to a horizontal (x) axis and a vertical (y) axis (and sometimes a depth, or z, axis).
plotter
n. Any device used to draw charts, diagrams, and other line-based graphics. Plotters use either pens or electrostatic charges and toner. Pen plotters draw on paper or transparencies with one or more colored pens. Electrostatic plotters "draw" a pattern on electrostatically charged dots on the paper and then apply toner and fuse it in place. Plotters use three basic types of paper handling: flatbed, drum, and pinch roller. Flatbed plotters hold the paper still and move the pen along both x and y axes. Drum plotters roll the paper over a cylinder. The pen moves along one axis while the drum, with the paper attached, moves along the other. Pinch-roller plotters are a hybrid of the two, in which the pen moves only along one axis while the paper is moved back and forth by small rollers.
Plug and Play
n. A set of specifications developed by Intel that allows a PC to configure itself automatically to work with peripherals such as monitors, modems, and printers. A user can "plug" in a peripheral and "play" it without manually configuring the system. A Plug and Play PC requires both a BIOS that supports Plug and Play and a Plug and Play expansion card. See also BIOS, expansion board, peripheral.
plug-in
n. 1. A small software program that plugs into a larger application to provide added functionality. 2. A software component that plugs into the Netscape Navigator. Plug-ins permit the Web browser to access and execute files embedded in HTML documents that are in formats the browser normally would not recognize, such as many animation, video, and audio files. Most plug-ins are developed by software companies who have proprietary software in which the embedded files are created. Compare helper application, helper program.
PNP transistor
n. A type of bipolar transistor in which a base of N-type material is sandwiched between an emitter and a collector of P-type material. The base, emitter, and collector are the three terminals of the transistor through which current flows. In a PNP transistor, holes (electron "vacancies") are the majority of the charge carriers, and they flow from the emitter to the collector. See also N-type semiconductor, P-type semiconductor. Compare NPN transistor.
point1
n. 1. A unit of measure used in printing, equal to approximately 1/72 of an inch. Character height and the amount of space (leading) between lines of text are usually specified in points. 2. A single pixel on the screen, identified by its row and column numbers. 3. A location in a geometric form, represented by two or more numbers that constitute its coordinates.
point2
vb. To move an arrow or other such indicator to a particular item or position on the screen by using direction keys or by maneuvering a pointing device such as a mouse.
point-and-click
adj. Enabling a user to select data and activate programs by using a mouse or other pointing device to move a cursor to a desired location ("point") and pressing a button on the mouse or other pointing device ("click").
PointCast
n. An Internet service that delivers and displays a personalized set of news articles to individual users. Unlike the World Wide Web and other Internet applications, PointCast is a push technology, where the server automatically uploads data without a specific command from the client. See also server (definition 2).
pointing device
n. An input device used to control an on-screen cursor for such actions as "pressing" on-screen buttons in dialog boxes, choosing menu items, and selecting ranges of cells in spreadsheets or groups of words in a document. A pointing device is often used to create drawings or graphical shapes. The most common pointing device is the mouse, which was popularized by its use with the Apple Macintosh. Other pointing devices include graphics tablets, styluses, light pens, joysticks, pucks, and trackballs. See also graphics tablet, joystick, light pen, mouse, puck, stylus, trackball.
point of presence
n. 1. A point in a wide area network to which a user can connect with a local telephone call. 2. A point at which a long distance telephone carrier connects to a local telephone exchange or to an individual user. Acronym: POP.
Point-to-Point Tunneling Protocol
n. A specification for virtual private networks in which some nodes of a local area network are connected through the Internet. See also virtual network. Acronym: PPTP.
polymorphism
n. In an object-oriented programming language, the ability to redefine a routine in a derived class (a class that inherited its data structures and routines from another class). Polymorphism allows the programmer to define a base class that includes routines that perform standard operations on groups of related objects, without regard to the exact type of each object. The programmer then redefines the routines in the derived class for each type, taking into account the characteristics of the object. See also class, derived class, object (definition 2), object-oriented programming.
Pong
n. The first commercial video game, a table tennis simulation, created by Nolan Bushnell of Atari in 1972.
POP3
n. Acronym for Post Office Protocol 3. This is the current version of the Post Office Protocol standard in common use on TCP/IP networks. See also Post Office Protocol, TCP/IP.
populate
vb. 1. To put chips in the sockets of a circuit board. 2. To import prepared data into a database from a file using a software procedure rather than by having a human operator enter individual records.
pop-up Help
n. An online help system whose messages appear as pop-up windows when the user clicks on a topic or area of the screen about which help is desired. Typically, a special form of click, such as clicking the right mouse button or Option-clicking, will activate pop-up Help, if it is available. See also balloon help.
pop-up menu
or popup menu n. In a graphical user interface, a menu that appears on-screen when a user selects a certain item. Pop-up menus can appear anywhere on the screen and generally disappear when the user selects an item in the menu. Also called popup. Compare drop-down menu, pull-down menu.
pop-up messages
n. The messages that appear when pop-up Help is used.
pop-up window
n. A window that appears when an option is selected. Typically, the window remains visible until the mouse button is released.
port1
n. See input/output port, port number.
port2
vb. 1. To change a program in order to be able to run it on a different computer. 2. To move documents, graphics, and other files from one computer to another.
portable
adj. 1. Capable of running on more than one computer system or under more than one operating system. Highly portable software can be moved to other systems with little effort, moderately portable software can be moved only with substantial effort, and nonportable software can be moved only with effort similar to or greater than the effort of writing the original program. 2. Light enough, rugged enough, and free enough of encumbering external connections to be carried by a user.
portable computer
n. Any computer designed to be moved easily. Portable computers can be characterized by size and weight as in the table below. k:\compdict\database\5011.doc
Portable Distributed Objects
n. Software from NeXT, running under UNIX, that supports an object model in which objects to be stored at various locations on a network can be accessed as though they were at a single location. Acronym: PDO.
Portable Document Format
n. The Adobe specification for electronic documents that use the Adobe Acrobat family of servers and readers. See also Acrobat, .pdf. Acronym: PDF.
portrait mode
n. A vertical print orientation in which a document is printed across the narrower dimension of a rectangular sheet of paper. This is the print mode typical of most letters, reports, and other such documents. Compare landscape mode.
POS
n. Acronym for point of sale. The place in a store at which goods are paid for. Computerized transaction systems, such as those in use at automated supermarkets, use scanners for reading tags and bar codes, electronic cash registers, and other special devices to record purchases at this point.
POSIX
n. Acronym for Portable Operating System Interface for UNIX. An IEEE standard that defines a set of operating-system services. Programs that adhere to the POSIX standard can be easily ported from one system to another. POSIX was based on UNIX system services, but it was created in a way that allows it to be implemented by other operating systems.
post
vb. To submit an article in a newsgroup or other online conference. The term is derived from the "posting" of a notice on a physical bulletin board. See also newsgroup.
postmaster
n. The logon name (and therefore the e-mail address) of an account that is responsible for maintaining e-mail services on a mail server. When an accountholder is having trouble with e-mail, a message to "postmaster" or "postmaster@machine.org.domain.name" will usually reach a human who can solve the problem.
Post Office Protocol
n. A protocol for servers on the Internet that receive, store, and transmit e-mail and for clients on computers that connect to the servers to download and upload e-mail. Acronym: POP.
PostScript
n. A page-description language from Adobe Systems that offers flexible font capability and high-quality graphics. The most well-known page-description language, PostScript uses English-like commands to control page layout and to load and scale outline fonts. Adobe Systems is also responsible for Display PostScript, a graphics language for computer displays that gives users of both PostScript and Display PostScript absolute WYSIWYG (what-you-see-is-what-you-get), which is difficult when different methods are used for displaying and printing. See also outline font, page-description language.
PostScript font
n. A font defined in terms of the PostScript page-description language rules and intended to be printed on a PostScript-compatible printer. PostScript fonts are distinguished from bitmapped fonts by their smoothness, detail, and faithfulness to standards of quality established in the typographic industry. See also PostScript. Compare screen font.
POTS
n. Acronym for Plain Old Telephone Service. Basic dial telephone connections to the public switched network, without any added features or functions. A POTS line is nothing but a phone line connected to a simple desktop telephone instrument.
PowerBook
n. Any of several computers in the family of portable Macintosh computers made by Apple.
power down
vb. To shut down (a computer); to turn off the power.
power failure
n. Loss of electricity, which causes a loss of unsaved data in a computer's random access memory (RAM) if no backup power supply is connected to the machine. Compare surge.
Power Macintosh
n. An Apple Macintosh computer based on the PowerPC processor. The first Power Macintoshes, 6100/60, 7100/66, and 8100/80, were unveiled in March 1994. Also called Power Mac. See also PowerPC.
Power-on key
n. A special key on the Apple ADB and Extended keyboards used for turning on a Macintosh II. The Power-on key is marked with a left-pointing triangle and is used in lieu of the on/off switch. There is no Power-off key; the system is shut down by choosing the Shut Down command from the Special menu.
power-on self test
n. A set of routines stored in a computer's read-only memory (ROM) that tests various system components such as RAM, the disk drives, and the keyboard to see if they are properly connected and operating. If problems are found, these routines alert the user by sounding a series of beeps or displaying a message, often accompanied by a diagnostic numeric value, to the standard output or standard error device (usually the screen). If the power-on self test is successful, it passes control to the system's bootstrap loader. See also bootstrap loader. Acronym: POST.
PowerPC
n. A microprocessor architecture developed in 1992 by Motorola and IBM, with some participation by Apple. A PowerPC microprocessor is RISC-based and superscalar, with a 64-bit data bus and a 32-bit address bus. It also has separate data and instruction caches, although the size of each varies by implementation. All PowerPC microprocessors have multiple integer and floating-point units, and all have an operating voltage of 3.3 volts, except for the 601, which operates at 3.6 volts. The operating speed and number of instructions executed per clock cycle varies with the implementation. The 601 is available in a 80-MHz or 100-MHz version and executes three instructions per clock cycle. The 603, available in 80-MHz, 100-MHz, and 200-MHz versions, executes three instructions per clock cycle. The 604, available in 100-MHz, 120-MHz, and 133-MHz versions, executes four instructions per clock cycle. The 620, available in a 133-MHz version, also executes four instructions per clock cycle. PowerPC is a registered trademark of IBM. See also microprocessor, RISC.
PowerPC Platform
n. A platform developed by IBM, Apple, and Motorola based on the 601 and later chips. This platform supports the use of multiple operating systems such as Mac OS, Windows NT, and AIX as well as software designed for those individual operating systems.
PowerPC Reference Platform
n. An open system standard developed by IBM. IBM's goal in designing the PowerPC Reference Platform was to ensure compatibility among PowerPC systems built by different companies. Apple's PowerPC Macintoshes are not yet compliant with the PowerPC Reference Platform, but future versions are expected to be. See also Common Hardware Reference Platform, open system, PowerPC. Acronym: PPCP., PReP (prep, P`R-E-P').
power supply
n. An electrical device that transforms standard wall outlet electricity (115-120 VAC in the United States) into the lower voltages (typically 5 to 12 volts DC) required by computer systems. Personal computer power supplies are rated by wattage; they usually range from about 90 watts at the low end to 250 watts at the high end.
power up
vb. To start up a computer; to begin a cold boot procedure; to turn on the power.
power user
n. A person adept with computers, particularly on an applications-oriented level rather than on a programming level. A power user is someone who knows a considerable amount about computers and is comfortable enough with applications to be able to work with their most sophisticated features.
PPP
n. Acronym for Point-to-Point Protocol. A data link protocol developed by the Internet Engineering Task Force in 1991 for dial-up telephone connections, such as between a computer and the Internet. PPP provides greater protection for data integrity and security than does SLIP, at a cost of greater overhead. Compare SLIP.
PPTP
See Point-to-Point Tunneling Protocol.
PRAM
n. Short for parameter RAM. A portion of RAM in Macintosh computers that contains configuration information such as the date and time, desktop pattern, and other control panel settings. See also RAM.
P-rating
n. Short for performance rating. A microprocessor rating system by IBM, Cyrix, and others, based on throughput in realistic applications. Formerly, microprocessor clock speed was widely used as a method of rating, but it does not account for differing chip architectures or different types of work people do with computers. See also central processing unit, clock (definition 1), microprocessor.
preemptive multitasking
n. A form of multitasking in which the operating system periodically interrupts the execution of a program and passes control of the system to another waiting program. Preemptive multitasking prevents any one program from monopolizing the system. Also called time-slice multitasking. See also multitasking.
Preferences
n. A menu choice in many graphical user interface applications that allows the user to specify how the application will act each time it is used. For example, in a word processing application the user may be allowed to specify whether the ruler will appear, whether the document will appear in the same way as it will print (including margins), and other choices. Also called Options, Prefs.
presentation graphics
n. The representation of business information, such as sales figures and stock prices, in chart form rather than as lists of numbers. Presentation graphics are used to give viewers an immediate grasp of business statistics and their significance. Common examples are area charts, bar charts, line charts, and pie charts. Also called business graphics.
presentation layer
n. The sixth of the seven layers in the International Organization for Standardization's Open Systems Interconnection (ISO/OSI) model for standardizing computer-to-computer communications. The presentation layer is responsible for formatting information so that it can be displayed or printed. This task generally includes interpreting codes (such as tabs) related to presentation, but it can also include converting encryption and other codes and translating different character sets. See also ISO/OSI model.
Presentation Manager
n. The graphical user interface provided with OS/2 versions 1.1 and later. The Presentation Manager derives from the MS-DOS-based Windows environment and provides similar capabilities. The user sees a graphical, window-oriented interface, and the programmer uses a standard set of routines for handling screen, keyboard, mouse, and printer input and output, no matter what hardware is attached to the system. See also OS/2, Windows.
preventive maintenance
n. Routine servicing of hardware intended to keep equipment in good operating condition and to find and correct problems before they develop into severe malfunctions.
A/B Switch box ~ America On-line AMI BIOS ~ Arithmetic Operation ARP ~ AVI Backbone ~ Bit Image Bit Map ~ Boot Disk Boot Drive ~ Bytes Per Inch C++ ~ Carrier Frequency carrier system ~ certification CGI ~ Chooser extension cipher ~ Clipper Chip clock ~ color color bits ~ communications satellite communications server ~ computer security CON ~ copy copy program ~ cycle time daemon ~ defragmentation demand paging ~ digitize DikuMUD ~ disk disk buffer ~ Document Style Semantics and Specification Language document window ~ dynamic Web page Easter egg ~ erase erase head ~ ezine F2F ~ finger2 firewall ~ font suitcase footer ~ FYI Game Control Adapter ~ GUI HAL ~ hot key1 hot key2 ~ Hz i486DX ~ internal modem internet ~ ISO 9660 ISO/OSI model ~ just-in-time K1 ~ knowledge base L1 cache ~ LU luggable computer ~ LZW compression MAC ~ MILNET mime ~ msec MTBF ~ MYOB named anchor ~ network drive Network File System ~ number crunching object ~ overwrite mode P5 ~ PC/XT keyboard PDA ~ pipeline processing piracy ~ preventive maintenance preview ~ pwd quasi-language ~ QWERTY keyboard R&D ~ registration marks Registry ~ RFI RF shielding ~ run-time library SAA ~ server error server push-pull ~ soft return software ~ style sheet stylus ~ System T1 ~ ToggleKeys token ~ typography UART ~ uupc V.120 ~ view2 viewer ~ VxD w3 ~ WinG WINS ~ WWW X.25 ~ X Windows Yahoo! ~ yotta- Z39.50 standard ~ Zulu time