A Gathering Place: Microsoft Glossary of Terms 42

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P5 ~ PC/XT keyboard

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

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n. Intel Corporation's internal working name for the Pentium microprocessor. Although it was not intended to be used publicly, the name P5 leaked out to the computer-industry trade press and was commonly used to reference the microprocessor before it was released. See also 586, Pentium.

packet

n. 1. A unit of information transmitted as a whole from one device to another on a network. 2. In packet-switching networks, a transmission unit of fixed maximum size that consists of binary digits representing both data and a header containing an identification number, source and destination addresses, and sometimes error-control data. See also packet switching.

packet assembler/disassembler

n. An interface between non-packet-switching equipment and a packet-switching network. Acronym: PAD.

Packet Internet Groper

n. See ping1 (definition 1).

packet switching

n. A message-delivery technique in which small units of information (packets) are relayed through stations in a computer network along the best route available between the source and the destination. A packet-switching network handles information in small units, breaking long messages into multiple packets before routing. Although each packet may travel along a different path, and the packets composing a message may arrive at different times or out of sequence, the receiving computer reassembles the original message. Packet-switching networks are considered to be fast and efficient. To manage the tasks of routing traffic and assembling/disassembling packets, such a network requires some "intelligence" from the computers and software that control delivery. The Internet is an example of a packet-switching network. Standards for packet switching on networks are documented in the CCITT recommendation X.25.

PAD

n. See packet assembler/disassembler.

page

n. 1. In word processing, the text and display elements to be printed on one side of a sheet of paper, subject to formatting specifications such as depth, margin size, and number of columns. 2. A fixed-size block of memory. When used in the context of a paging memory system, a page is a block of memory whose physical address can be changed via mapping hardware. See also EMS, memory management unit, virtual memory. 3. In computer graphics, a portion of display memory that contains one complete full-screen image; the internal representation of a screenful of information.

page break

n. The point at which the flow of text in a document moves to the top of a new page. Most word processors automatically place page breaks when the material on the page reaches a specified maximum. By contrast, a "hard" or "manual" page break is a command or code inserted by the user to force a page break at a specific place in the text. See also form feed.

paged address

n. In the 80386, i486, and Pentium paged-memory architecture, an address in memory created by combining the process of segment translation and page translation. In the paged-memory scheme, which requires that the microprocessor's paging feature be enabled, logical addresses are transformed into physical addresses in two steps: segment translation and page translation. The first step, segment translation, converts a logical to a linear address--an address that refers indirectly to a physical address. After the linear address is obtained, the microprocessor's paging hardware converts the linear address to a physical address by specifying a page table (an array of 32-bit page specifiers), a page (a 4-KB unit of contiguous addresses within physical memory) within that table, and an offset within that page. This information collectively refers to a physical address.

Page Down key

n. A standard key (often labeled "PgDn") on most computer keyboards whose specific meaning is different in different programs. In many cases, it moves the cursor down to the top of the next page or a specific number of lines.

page fault

n. The interrupt that occurs when software attempts to read from or write to a virtual memory location that is marked "not present." The mapping hardware of a virtual memory system maintains status information about every page in the virtual address space. A page either is mapped onto a physical address or is not present in physical memory. When a read or write to an unmapped virtual address is detected, the memory management hardware generates the page fault interrupt. The operating system must respond to the page fault by swapping in the data for the page and updating the status information in the memory management unit. See also page (definition 2), swap (definition 2), virtual memory.

page layout

n. In desktop publishing, the process of arranging text and graphics on the pages of a document. Page-layout programs excel in text placement and management of special effects applied to text. Although page-layout programs are generally slower than word-processing programs, they can perform such advanced tasks as flowing text into complex multicolumn page designs, printing documents in signatures, managing color separations, and supporting sophisticated kerning and hyphenation.

page makeup

n. The assembling of graphics and text on a page in preparation for printing.

Page Up key

n. A standard key (often labeled "PgUp") on most computer keyboards whose specific meaning is different in different programs. In many cases, it moves the cursor up to the top of the previous page or a specific number of lines.

paging

n. A technique for implementing virtual memory. The virtual address space is divided into a number of fixed-size blocks called pages, each of which can be mapped onto any of the physical addresses available on the system. Special memory management hardware (MMU or PMMU) performs the address translation from virtual addresses to physical addresses. See also memory management unit, paged memory management unit, virtual memory.

paint1

n. A color and pattern used with graphics programs to fill areas of a drawing, applied with tools such as a paintbrush or a spraycan.

paint2

vb. To fill a portion of a drawing with paint.

paintbrush

n. An artist's tool in a paint program or another graphics application for applying a streak of solid color to an image. The user can usually select the width of the streak. See also paint program. Compare spraycan.

palmtop

n. A portable personal computer whose size enables it to be held in one hand while it is operated with the other hand. A major difference between palmtop computers and laptop computers is that palmtops are usually powered by off-the-shelf batteries such as AA cells. Palmtop computers typically do not have disk drives; rather, their programs are stored in ROM and are loaded into RAM when they are switched on. More recent palmtop computers are equipped with PCMCIA slots to provide wider flexibility and greater capability. See also handheld PC, PCMCIA slot, portable computer. Compare laptop.

Pantone Matching System

n. In graphic arts and printing, a standard system of ink color specification consisting of a swatch book in which each of about 500 colors is assigned a number. See also color model. Acronym: PMS.

PAP

n. 1. Acronym for Password Authentication Protocol. A method for verifying the identity of a user attempting to log on to a Point-to-Point Protocol (PPP) server. PAP is used if a more rigorous method, such as the Challenge Handshake Authentication Protocol (CHAP), is not available or if the user name and password that the user submitted to PAP must be sent to another program without encryption. 2. Acronym for Printer Access Protocol. The protocol in AppleTalk networks that governs communication between computers and printers.

paper feed

n. A mechanism that moves paper through a printer. In laser printers and other page printers, the paper feed is usually a series of rollers that firmly grip and align the paper. In dot-matrix printers, the paper feed is usually a pin feed or tractor feed, in which small pins drag or push paper that has detachable edges punched with sprocket holes. Friction feed is another type of paper feed, in which the paper is gripped between the platen and pressure rollers and pulled by rotation of the platen.

paperless office

n. The idealized office in which information is entirely stored, manipulated, and transferred electronically rather than on paper.

paradigm

n. An archetypical example or pattern that provides a model for a process or system.

paragraph

n. 1. In word processing, any part of a document preceded by one paragraph mark and ending with another. To the program, a paragraph represents a unit of information that can be selected as a whole or given formatting distinct from the surrounding paragraphs. 2. On IBM and other computers built around the Intel 8088 or 8086 microprocessor, a 16-byte section of memory beginning at a location (address) that can be divided evenly by 16 (hexadecimal 10).

parallel

adj. 1. Of or relating to electronic circuits in which the corresponding terminals of two or more components are connected. 2. In geometry and graphics, of, relating to, or being lines that run side by side in the same direction in the same plane without intersecting. 3. In data communications, of, relating to, or being information that is sent in groups of bits over multiple wires, one wire for each bit in a group. See also parallel interface. Compare serial. 4. In data handling, of or relating to handling more than one event at a time, with each event having its own portion of the system's resources. See also parallel processing.

parallel computing

n. The use of multiple computers or processors to solve a problem or perform a function. See also array processor, massively parallel processing, pipeline processing, SMP.

parallel port

n. The input/output connector for a parallel interface device. See also input/output port.

parallel printer

n. A printer that is connected to the computer via a parallel interface. In general, a parallel connection can move data between devices faster than a serial connection can. The parallel interface is preferred in the IBM PC world because its cabling is more standardized than that of the serial interface and because the MS-DOS operating system assumes that the system printer is attached to the parallel port. See also parallel interface. Compare serial printer.

parallel server

n. A computer system that implements some form of parallel processing to improve its performance as a server. See also SMP server.

parallel transmission

n. The simultaneous transmission of a group of bits over separate wires. With microcomputers, parallel transmission refers to the transmission of 1 byte (8 bits). The standard connection for parallel transmission is known as the Centronics interface. See also Centronics parallel interface. Compare serial transmission.

parameter

n. In programming, a value that is given to a variable, either at the beginning of an operation or before an expression is evaluated by a program. Until the operation is completed, a parameter is effectively treated as a constant value by the program. A parameter can be text, a number, or an argument name assigned to a value that is passed from one routine to another. Parameters are used as a means of customizing program operation. See also argument, pass by address, pass by value, routine.

PARC

n. See Xerox PARC.

parity

n. The quality of sameness or equivalence, in the case of computers usually referring to an error-checking procedure in which the number of 1s must always be the same--either even or odd--for each group of bits transmitted without error. If parity is checked on a per-character basis, the method is called vertical redundancy checking, or VRC; if checked on a block-by-block basis, the method is called longitudinal redundancy checking, or LRC. In typical modem-to-modem communications, parity is one of the parameters that must be agreed upon by sending and receiving parties before transmission can take place. Types of parity are shown in the following table. See also parity bit, parity check, parity error. k:\compdict\database\2297.doc

parity bit

n. An extra bit used in checking for errors in groups of data bits transferred within or between computer systems. With microcomputers, the term is frequently encountered in modem-to-modem communications, in which a parity bit is often used to check the accuracy with which each character is transmitted, and in RAM, where a parity bit is often used to check the accuracy with which each byte is stored.

parity check

n. The use of parity to check the accuracy of transmitted data. See also parity, parity bit.

parity error

n. An error in parity that indicates an error in transmitted data or in data stored in memory. If a parity error occurs in communications, all or part of a message must be retransmitted; if a parity error occurs in RAM, the computer usually halts. See also parity, parity bit.

park

vb. To position the read/write head over a portion of a disk that stores no data (and therefore can never be damaged) or beyond the surface of the disk, prior to shutting down the drive, especially in preparation for moving it. Parking can be performed manually, automatically, or, most typically, by a disk utility program.

parse

vb. To break input into smaller chunks so that a program can act upon the information.

partition

n. 1. A logically distinct portion of memory or a storage device that functions as though it were a physically separate unit. 2. In database programming, a subset of a database table or file.

Pascal

n. A concise procedural language designed between 1967 and 1971 by Niklaus Wirth. Pascal, a compiled, structured language built upon ALGOL, simplifies syntax while adding data types and structures such as subranges, enumerated data types, files, records, and sets. See also ALGOL, compiled language. Compare C.

password

n. A security measure used to restrict access to computer systems and sensitive files. A password is a unique string of characters that a user types in as an identification code. The system compares the code against a stored list of authorized passwords and users. If the code is legitimate, the system allows the user access at whatever security level has been approved for the owner of the password.

Password Authentication Protocol

n. See PAP (definition 1).

password protection

n. The use of passwords as a means of allowing only authorized users access to a computer system or its files.

paste

vb. To insert text or a graphic that has been cut or copied from one document into a different location in the same or a different document. See also cut, cut and paste.

patch1

n. A piece of object code that is inserted in an executable program as a temporary fix of a bug.

patch2

vb. In programming, to repair a deficiency in the functionality of an existing routine or program, generally in response to an unforeseen need or set of operating circumstances. Patching is a common means of adding a feature or a function to a program until the next version of the software is released. Compare hack (definition 2), kludge (definition 2).

path

n. 1. In communications, a link between two nodes in a network. 2. A route through a structured collection of information, as in a database, a program, or files stored on disk. 3. In programming, the sequence of instructions a computer carries out in executing a routine. 4. In information processing, such as the theory underlying expert (deductive) systems, a logical course through the branches of a tree of inferences leading to a conclusion. 5. In file storage, the route followed by the operating system through the directories in finding, sorting, and retrieving files on a disk. 6. In graphics, an accumulation of line segments or curves to be filled or drawn.

pattern recognition

n. 1. A broad technology describing the ability of a computer to identify patterns. The term usually refers to computer recognition of visual images or sound patterns that have been converted to arrays of numbers. 2. The recognition of purely mathematical or textual patterns.

Pause key

n. 1. A key on a keyboard that temporarily stops the operation of a program or a command. The Pause key is used, for example, to halt scrolling so that a multiscreen listing or document can be read. 2. Any key that creates a pause in an operation. For example, many game programs have a Pause key, often simply the P key, that temporarily suspends the game.

PBX

n. Acronym for Private Branch Exchange. An automatic telephone switching system that enables users within an organization to place calls to each other without going through the public telephone network. Users can also place calls to outside numbers.

n. 1. A microcomputer that conforms to the standard developed by IBM for personal computers, which uses a microprocessor in the Intel 80x86 family (or compatible) and can execute the BIOS. See also 8086, BIOS, clone, IBM PC. 2. A computer in IBM's Personal Computer line. Also called IBM PC. See also PC-compatible (definition 1). See personal computer.

PC Card

n. A trademark of the Personal Computer Memory Card International Association (PCMCIA) that is used to describe add-in cards that conform to the PCMCIA specification. A PC Card is a removable device, approximately the same size as a credit card, that is designed to plug into a PCMCIA slot. Release 1 of the PCMCIA specification, introduced in June 1990, specified a Type I card that is 3.3 millimeters thick and is intended to be used primarily as a memory-related peripheral. Release 2 of the PCMCIA specification, introduced in September 1991, specifies both a 5-millimeter-thick Type II card and a 10.5-millimeter-thick Type III card. Type II cards accommodate devices such as modem, fax, and network cards. Type III cards accommodate devices that require more space, such as wireless communications devices and rotating storage media (such as hard disks). See also PCMCIA, PCMCIA slot.

PC-compatible

adj. Conforming to IBM PC/XT and PC/AT hardware and software specifications, which has been the de facto standard in the computing industry for personal computers that use the Intel 80x86 family or compatible chips. Most PC-compatible computers today are developed outside of IBM; they are still sometimes referred to as clones. Also called IBM PC. See also 8086, clone, de facto standard, IBM AT. See Wintel.

PC-DOS

n. Acronym for Personal Computer Disk Operating System. The version of MS-DOS sold by IBM. MS-DOS and PC-DOS are virtually identical, although filenames of utility programs sometimes differ in the two versions. See also MS-DOS.

PCI local bus

n. Short for Peripheral Component Interconnect local bus. A specification introduced by Intel Corporation that defines a local bus system that allows up to 10 PCI-compliant expansion cards to be installed in the computer. A PCI local bus system requires the presence of a PCI controller card, which must be installed in one of the PCI-compliant slots. Optionally, an expansion bus controller for the system's ISA, EISA, or Micro Channel Architecture slots can be installed as well, providing increased synchronization over all the system's bus-installed resources. The PCI controller can exchange data with the system's CPU either 32 bits or 64 bits at a time, depending on the implementation, and it allows intelligent, PCI-compliant adapters to perform tasks concurrently with the CPU using a technique called bus mastering. The PCI specification allows for multiplexing, a technique that permits more than one electrical signal to be present on the bus at one time. See also local bus. Compare VL bus.

PCL

n. See Printer Control Language.

PCMCIA

n. Acronym for Personal Computer Memory Card International Association. A group of manufacturers and vendors formed to promote a common standard for PC Card-based peripherals and the slot designed to hold them, primarily on laptop, palmtop, and other portable computers, as well as for intelligent electronic devices. PCMCIA is also the name of the standard for PC Cards, first introduced in 1990 as release 1. See also PC Card, PCMCIA slot.

PCMCIA connector

n. The 68-pin female connector inside a PCMCIA slot designed to hold the 68-pin male connector on a PC Card. See also PC Card, PCMCIA slot.

PCMCIA slot

n. An opening in the housing of a computer, peripheral, or other intelligent electronic device designed to hold a PC Card. Also called PC Card slot. See also PC Card, PCMCIA connector.

PC memory card

n. 1. An add-in circuit card that increases the amount of RAM in a system. See also memory card. 2. A Type I PC Card as specified by PCMCIA. In this context, such a card consists of conventional static RAM chips powered by a small battery and is designed to provide additional RAM to the system. See also PC Card. Compare flash memory.

PC/XT

n. The original IBM Personal Computer, introduced in 1981, which used the Intel 8088 CPU. See also IBM PC.

PC/XT keyboard

n. The original keyboard for the IBM Personal Computer. Strong, reliable, and equipped with 83 keys, the PC/XT keyboard offers a typist an audible click. See also IBM PC, PC/XT.

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