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Glossary P What is a PDF file? PDF (Portable Document Format) is a file format developed by Adobe Systems as a means of distributing compact, platform-independent documents. It is superficially similar to HTML; a PDF document may contain images and text, as well as hyperlinks. However, as PDF is based on a variant of PostScript, each document is self-contained, packing text, graphics, and often fonts into a single file. With the aid of Adobe Acrobat, many desktop publishing applications can be used to create PDF files. For this reason and because PDF documents are World Wide Web accessible, yet display exactly as intended, print publishers often favor PDF over HTML. You can view PDF files with either the Adobe Acrobat Reader or via a Web browser with the PDF Viewer plug-in. To download these programs or find out more about PDF, visit Adobe's Web site: http://www.adobe.com/products/acrobat/ The plug-in is included with current versions of Acrobat Reader. Note: In Mac OS, CD-ROM file-sharing preferences are also called PDF files. They are unrelated to Adobe's Portable Document Format. Also see:
What is PC-cillin? PC-cillin is a software tool used to protect against and remove computer viruses. It can protect against and remove most known viruses, including boot sector, stealth, and Microsoft Word and Excel macro viruses. The list of viruses that can be detected and removed by PC-cillin grows as new viruses are discovered. Updates for PC-cillin are made available over the Internet periodically. For more information, see the Trend Micro PC-cillin page at: http://antivirus.com/pc-cillin/ Also see:
What is PCMCIA, and what is a PC card? PCMCIA is an acronym for Personal Computer Memory Card International Association; the acronym is pronounced as separate letters. PCMCIA is a non-profit trade association and standards body consisting of some 500 companies. PCMCIA has developed a standard for small, credit card-sized devices, called PC cards, that are often used in notebook computers. (Adapters are available that allow PC cards to be used in desktop computer systems.) In the past, the cards were known as PCMCIA cards, but they are now referred to as PC cards, PC card hosts, and PC card software. PCMCIA refers to the association and standards body. A PC card slot is an expansion slot often found in notebook computers that allows for the easy and quick addition of a host of different devices. Originally designed for adding memory to portable computer systems, the PC card standard has been updated several times since its original creation. PC cards are plug-and-play devices that are often hot-swappable (i.e., cards may be removed and inserted with the computer power turned on, without rebooting) under Mac OS and Windows 95 and beyond. (Windows NT, however, has more limited support for PC cards, and you cannot change cards on the fly.) Many systems will give a familiar beep sound from the computer's speaker when you remove or insert a card. Differences between PC cards There are three different types of PC cards. All three have the same rectangular size (85.6 by 54 millimeters), but different thicknesses.
For more about the content of the PC card standard, see the Technology Overviews at: Differences between PC card slots As with the physical PC cards, PC slots also come in three sizes:
Most notebook computer systems come with two PC card slots that allow for the use of two type I or type II PC cards and one type III PC card. The PC card slots are stacked with one above the other. Usually, type III PC cards fit only in the bottom slot. Common PC card devices Following is a list of common PC card devices:
Cardbus Many laptop manufacturers now advertise their PC card slots as cardbus compatible, or they simply identify the slots as cardbus slots. Cardbus is an extension of the latest PCMCIA standard, which expands the bus bandwidth and throughput to 32 bits at 33Mhz. In contrast, the older PC card standard was 16 bits at 8Mhz. Cardbus is analogous to the PCI slots in desktops, while the older PC card standard is analogous to ISA. The newer cardbus slot can accommodate an older 16-bit PC card, but an older PC card slot cannot accept newer cardbus cards. To tell if your PC card is cardbus, look on the interface end of the card. Cardbus devices will have a notched metal plate on that end. While not technically accurate, some vendors and technicians refer to the older style 16-bit PC card as PCMCIA in order to contrast it with 32-bit cardbus cards, which makes them sound like competing standards. However, cardbus is an extension to the PCMCIA standard, not a replacement. For additional information, see: http://www.accurite.com/PCMCIAprimer.html Also see: What is Pine, and where can I find more information about it? Pine is a popular mail and Usenet client for Unix and Windows. Developed at the University of Washington, it offers an intuitive, easy-to-use menu interface and supports MIME, IMAP, and PGP. Note: Pine's name was originally a play on "Elm", but has been redefined as the acronym "Program for Internet Mail and News". Pine is not typically spelled in all capital letters, however. Also see: What is PostScript, and what is a PostScript file? PostScript is a page description language (PDL) developed by Adobe Systems. In essence, it is a programming language for describing how a page is to be printed or displayed. (Examples of other PDLs include Envoy, PDF, and PCL.) PostScript consists of functions for describing and positioning lines, shapes, fills, and other graphical elements, and for placing and formatting text. Originally conceived as a means for communicating with printing devices, PostScript has been adapted for screen displays (Display PostScript, as used by NeXT computers), and for embedding graphics in documents (Encapsulated PostScript, or EPS). You can write a PostScript program by hand and send it to a PostScript printer, which will interpret the commands and print a page. For an example of PostScript code, visit this Adobe Magazine page: http://www.adobe.com/products/adobemag/archive/spirogf1.html For the most part, however, PostScript code is generated by other computer programs. For example, if you use Microsoft Word and print a page to an installed PostScript printer, the printer driver converts the page Word sent it into PostScript code, and then sends the PostScript code to the printer. The printer understands and interprets the PostScript commands and prints out the page. A PostScript file results when you send the PostScript program somewhere other than to the printer (e.g., to the hard drive). You can store the file, or send it via the network or storage media to another location for printing. PostScript files contain all the necessary information to print out the document, including graphics and fonts. See the documents under "Also see:" below for instructions on creating and manipulating PostScript files. To ensure cross-platform support, if you plan to send PostScript files to others, you should use common printer-resident fonts in your documents. The Times and Helvetica fonts are present on practically all PostScript printers. Also, there are three levels (versions) of the PostScript language so far. Furthermore, some printers were made without Adobe's PostScript interpreter, but with compatible interpreters instead. For more in-depth information about PostScript, search Adobe's Web site at: Also see:
What is PPP (Point-to-Point Protocol), and why would I want it? PPP stands for point-to-point protocol, which is a technology for connecting to networks over standard serial (telephone) lines. In its most common implementation, users connect their personal computers to the Internet with PPP over a high-speed modem. It is similar to SLIP, but has more features and is more robust, providing error-checking and supporting the PAP and CHAP models of authentication. Unlike programs such as ZTerm and Telix, which use your modem to connect to a terminal server, with PPP you have a more direct and flexible connection to the Internet. Many of the functions that you access by dialing up a terminal server and running them on a remote host (such as a Unix shell account), you can also do from your own computer. For instance, PPP allows you to use e-mail, newsreading, and Web browser programs that take advantage of your workstation's graphics capabilities, graphical user interface, etc. Some examples of what a PPP connection allows:
For a technical review of the PPP standard, read RFC 1661 at: ftp://ftp.isi.edu/in-notes/rfc1661.txt Also, consult the newsgroup comp.protocols.ppp . Also see:
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