snap to grid a mode in which a drawing program lines up all objects on a (nonprinting) grid. This makes it easy to line up parts of diagrams that are drawn separately, rather like drawing with a pencil on graph paper. sneakernet (slang) the practice of transferring files from one computer to another by carrying a diskette across the room. sniffer a hardware device or computer program for intercepting data pack- ets as they pass through a network either to test the network or to inter- cept other people’s confidential data. See FIREWALL. snowflake see FRACTAL; KOCH SNOWFLAKE. SOAP (Simple Object Access Protocol) a protocol for executing methods (procedures, functions, subroutines) on a remote computer using XML to encode the data and HTTP to perform the data transmission. SOAP can be used by COM, CORBA, and other kinds of distributed applica- tions. See COM; CORBA; HTTP; PROTOCOL; XML. social networking site a web site where users can build a personalized community to socialize with. Common features include a customizable profile, the ability to add other users as friends, the ease of sharing pic- tures, music, text, and links, and built-in chat and mail features. Social networking sites are becoming one of the most popular methods of con- tacting friends and organizing gatherings. Social networking sites are often criticized for the amount of time that they can consume, and many schools and libraries specifically block them. There is concern that advertising is often mixed in with content seamlessly and the term FRIEND has lost much of its original meaning when applied to every acquaintance. There are also numerous privacy concerns, particularly with younger users who may be too eager to share personal information with strangers. social responsibility see EICC. socket 1. an electrical connector into which another connector, with pins, can be inserted. 2. a communication path between two computer programs not neces- sarily running on the same machine. Sockets are managed by a socket DEVICE DRIVER that establishes network connections as needed; the pro- grams that communicate through sockets need not know anything about how the network functions. Sockpuppet a fake online identity created by another user so that the user talks through another mouthpiece while pretending not to (like a literal sock puppet). Sockpuppets often pop up in forums to defend the original person’s arguments or to deliver praise in order to make the user seem more popular. SODIMM (Small Outline Dual Inline Memory Module) a smaller type of DIMM commonly used in laptop and notebook computers. See DIMM. 443 SODIMM 7_4105_DO_CompInternetTerms_S 12/29/08 10:37 AM Page 443 soft brush (in paint programs) a category of tools that includes paint- brushes, airbrushes or spray cans, smear paintbrushes, and clone tools. All of these tools leave soft edges and have transparent strokes. These tools are sometimes grouped together in the toolbox and have similar dialog boxes for their settings. soft copy computer output that is only viewable on the computer screen. Contrast HARD COPY. soft edge in a graphical image, a boundary between two areas that is dif- fuse and somewhat blurred. See Figure 127, page 226. soft error an error or defect on a data storage device that is present only intermittently; an error that goes away when the same operation is tried again. Contrast HARD ERROR. soft hyphen a hyphen that is used only when the word falls at the end of a line; sometimes called a DISCRETIONARY HYPHEN. Contrast HARD HYPHEN; REQUIRED HYPHEN. soft page, soft page break an invisible control code that indicates where the text will break at the end of a page. Unlike a HARD PAGE, a soft page break is inserted by the program and will move if the amount of text on the page changes. See WRAP. software programs that tell a computer what to do. The term contrasts with hardware, which refers to the actual physical machines that make up a computer system. The hardware by itself is of little value without the instructions that tell it what to do. Software can be classified into system software (see OPERATING SYS- TEM) and application software. For examples of common types of appli- cation software, see WORD PROCESSING, SPREADSHEET, DATABASE MANAGEMENT. For information on creating software, see PROGRAMMING and PROGRAMMING LANGUAGE. software engineering the art and science of designing and constructing software. The computer industry has learned from bitter experience that large programs cannot be constructed as casually as small ones. Some principles of software engineering include the following: 1. Before starting a project, estimate the amount of labor it will require, based on previous experience. Err on the side of caution. Do not reduce an estimate just because a manager or customer wishes it were lower. 2. Allow adequate time for planning. Decide exactly what is needed, and if possible, write some of the documentation for the finished product before starting to write the program. 3. “Freeze” the specifications when planning is complete. Make sure clients and higher management understand that any further changes will delay completion and raise costs. The only excep- tions are changes proposed by the programmers in order to sim- plify implementation and improve performance. soft brush 444 7_4105_DO_CompInternetTerms_S 12/29/08 10:37 AM Page 444 4. Set priorities. Which is more important, finishing on time or imple- menting the full set of features? Can the product be developed incrementally, as a minimal first version followed by upgrades? 5. Use reliable programming techniques, including STRUCTURED PRO- GRAMMING and appropriate use of COMMENTs. 6. Insist that programmers remove errors as soon as they are found; do not leave debugging for later. You cannot build the upper sto- ries if the foundation is not solid. 7. Keep programmers’ morale high. Long working hours, although traditional in Silicon Valley, do not increase productivity; few peo- ple really work more than eight hours a day no matter how long they are at the office. 8. Do not add personnel to a project that is running late; the time taken to orient the new programmers will delay it further. Instead, find ways to help the current programmers work more efficiently. Shield them from unnecessary meetings, administrative chores, and even telephone calls. 9. Deadline crises are a symptom of incompetent management. A well-managed project gets finished on time without going into “crunch mode.” If a manager does not know how long a project will take, that’s not the employees’ fault. If the time needed cannot be estimated in advance, everyone should realize it rather than relying on wishful thinking. See also COMMENTS; CREEPING FEATURISM; STRUCTURED PROGRAMMING. software interrupt see INTERRUPT. software license an agreement between the publisher of a computer program and the person who buys a copy of it, allowing the software to be used. Some licenses specify that when you buy a copy of a program, you do not really own the copy but have merely bought the right to use it in cer- tain ways. Normally, the license allows you to make a working copy of the program, which would otherwise be forbidden by copyright law (see COPYRIGHT). Most licenses allow a single copy of the program to be used on only one machine at a time. It can be copied for backup purposes, and it can be moved from one machine to another, but it cannot be actually in use in two places at once. Thus you are forbidden to load the same program into more than one machine through a network (see LOCAL-AREA NET- WORK ). However, it is usually permissible for several people to use the same program on a multi-user machine with a single CPU. A site license allows unlimited copying of a program for use by a sin- gle organization at a specified site. A site license is often much cheaper than the purchase of multiple copies. Another alternative for schools and colleges is the use of student editions of software; these are less power- ful than the commercial versions and are sold at much lower prices. Many aspects of software licenses have not yet been tested in court. In particular, the license document is sometimes packed where the user can- not see it until after buying and opening the software package. In such cases, it can hardly be described as a valid contract. When dealing with 445 software license 7_4105_DO_CompInternetTerms_S 12/29/08 10:37 AM Page 445 unclear or unreasonable licenses, users should make a good-faith effort to obey copyright law and to avoid depriving the publisher of income. See also ACTIVATE (definition 3); EULA; FREE SOFTWARE; SHRINKWRAP LICENSE. software patent a patent (a legal grant of exclusive ownership for a limited time to the creator of a work of intellectual property) that protects a com- puter program. In 1981, the U.S. Supreme Court ruled that software can be patented (Diamond v. Diehr). However, the issue is still controversial. Open source advocates (see www.nosoftwarepatents.com) think software patents impede innovation, since others are not allowed to use the patented software without a license from the patent owner. Patents are not supposed to be applied to ideas, such as mathematical theorems, but it may be difficult to distinguish patentable software code from a non- patentable mathematical idea. Others argue that patent protection is essential for software develop- ment because the programmers need to earn income from their work. In 2005, the European Parliament rejected a proposal for a common system of software patents in the European Union. The issue is still being debated as this book goes to press. SOHO abbreviation for “small office, home office.” (Soho is also the name of districts in London and New York City.) Solaris the version of UNIX sold by Sun Microsystems. See SUN WORK- STATIONS. solder metal which is melted to join other metals without melting them. Most solder consists mainly of tin. Until recently, the solder in electronic equipment was usually 60% tin and 40% lead, but in order to reduce the amount of poisonous lead in landfills, the electronics industry is switch- ing to tin-antimony and other lead-free solders. See ROHS. solver 1. a computer program that solves equations that may have variables on either side of the equal sign, such as x = 1 + 1/x. This contrasts with ordinary calculators, spreadsheets, and programming languages, which can evaluate only expressions that consist entirely of known values. 2. an add-on for Microsoft Excel that can solve some kinds of opti- mization problems. The user specifies a target cell that is to be maxi- mized or minimized; some cells representing variables that can be changed; and some constraints, such as specifying that the values in cer- tain cells must be less than or greater than specific values. sort to arrange items in numerical or alphabetical order. Many different algorithms can be used to sort a group of items. If the number of items is small, it is probably best to use an algorithm that can be represented by a short program. If the number of data items is large, then it is more important to use a faster algorithm, even if it is complicated. Some algorithms assume that the data items have been read into the mem- ory of the computer. However, if there is a very large number of items, it will be necessary to use an algorithm that works when the data items are software patent 446 7_4105_DO_CompInternetTerms_S 12/29/08 10:37 AM Page 446 stored on an auxiliary storage device. Since sorting is such a common operation, many operating systems include built-in sorting algorithms. For examples of specific sorting algorithms, see BUBBLE SORT; INSERTION SORT; MERGE SORT; QUICKSORT; RADIX SORT; SELECTION SORT; SHELL SORT. Sound Blaster a line of popular sound cards for PCs marketed by Creative Labs, Inc., of Milpitas, California. Their web address is www.soundblaster.com. sound card a circuit board that can be added to a computer to enable or improve its ability to record and reproduce sound. Most current mother- boards now include the function of a sound card, but higher audio qual- ity can be obtained by adding a separate sound card. Sound cards often include other features such as a MIDI musical instrument interface, a controller for a CD-ROM drive, and an audio amplifier that can drive speakers. See Figure 244. FIGURE 244. Sound card connections source 1. see SOURCE CODE. 2. a place from which information is copied; the opposite of TARGET. 3. one of the three parts of a field-effect transistor (see FIELD-EFFECT TRANSISTOR). 4. an audio signal. source code 1. a computer program written in a programming language, such as C or Java, as opposed to the machine-language OBJECT CODE into which the compiler translates it. See COMPILER. 2. the HTML code or other special code that underlies a web page or other presentation. To view a web page as source code means to view the HTML code itself rather than the display that results from it. See HTML. source program a program written in a programming language (e.g., Pascal, C, or C++) and fed into a computer. The compiler translates the program into a machine-language object program. SP1, SP2 abbreviations for Service Pack 1 and Service Pack 2, which denote update packages for various software products. spaghetti code (slang) a disorganized computer program using many GO TO statements, as easy to read as a plate of spaghetti. Contrast STRUCTURED PROGRAMMING. 447 spaghetti code 7_4105_DO_CompInternetTerms_S 12/29/08 10:37 AM Page 447 spam unsolicited and unwelcome advertisements sent to people via e-mail or posted in newsgroups. “Spammers” have discovered that they can reach a large audience at low cost on the Internet by posting the same message to all available newsgroups or e-mailing it to all possible addresses. Spamming is considered seriously unethical for two reasons. First, newsgroups and e-mail would be useless if they routinely contained unwanted material. Second, the cost of transporting e-mail and news- group postings is not paid by the sender; it is paid by the recipient’s site and other sites along the way. Thus, it is important not to impose expenses on people by sending them unwanted material. In some places, spamming by e-mail is illegal, and there is a strong movement to prohibit it everywhere. More importantly, almost all Internet service providers (ISPs) flatly prohibit both e-mail and news- group spam. The few ISPs that allow spamming are ostracized by other sites, which refuse to accept any data from them. See CAN-SPAM; COMPUTER ETHICS; COMPUTER LAW; NETIQUETTE; ZOMBIE. Experts advise that you should never reply to spam, even to ask to be taken off the mailing list, because that will merely tell the spammer that he has hit a valid address. It is not clear why spam was named after a processed-meat product made by Hormel, but a Monty Python comedy act may be involved. For Hormel’s response to the situation, see www.spam.com. spam filter a piece of software that distinguishes SPAM from ordinary e- mail. Spam filters are used in most major e-mail systems and can also run on an individual’s computer. The way spam is recognized is kept secret, but it involves analysis of vocabulary, recognition of key phrases, and identification of known spam sites. To try to get around spam filters, spammers misspell the names of products and often include large numbers of irrelevant words. See BAYESIAN SPAM FILTER. spammer a person who sends out SPAM. Spammers are viewed with great contempt by the entire Internet community. SPARC (Scalable Processor Architecture) a microprocessor developed by Sun Microsystems and used in Sun Sparcstations as well as computers made by other manufacturers. It uses RlSC architecture to achieve very high speed. See RISC; SUN WORKSTATIONS; WORKSTATION. S/PDIF (Sony/Philips Digital Interface) a format for hardware and soft- ware for transferring digital audio files, used on CD players and other audio devices. speaker-dependent, speaker-independent see SPEECH RECOGNITION. special characters characters that cannot be typed directly from the key- board, but require entering a special code or selection through the KeyCaps applet (Macintosh) or the Character Map (Windows). Windows software accesses these special characters in many different ways. If you prefer to keep your hands on the keyboard, you can type spam 448 7_4105_DO_CompInternetTerms_S 12/29/08 10:37 AM Page 448 most special characters by holding down the Alt key and typing a four- digit code on the numeric keypad. (See the table of standard Windows characters at ANSI.) Macintosh users can type special characters by hold- ing down the Option or Ctrl buttons while typing (here the Option key acts like another Shift key). KeyCaps lets you see which typewriter key corresponds to the desired character. See also ANSI; EXPERT SET; IBM PC; UNICODE. specular highlight a bright point of light on a reflective or shiny surface. speech recognition the use of computers to recognize spoken words. This is a nontrivial task because the same spoken word does not produce entirely the same sound waves when pronounced by different people or even when pronounced by the same person on more than one occasion. The computer must digitize the sound, transform it to discard unneeded information, and finally try to match it with words stored in a dictionary. Most speech recognition systems are speaker-dependent; they have to be trained to recognize a particular person’s speech and can then distin- guish thousands of words (but only the words they were trained on). Speaker-independent speech recognition is less effective. The biggest demand for speech recognition arises in situations in which typing is dif- ficult or impossible, such as equipment for the handicapped, highly portable equipment, and computers that are to be accessed by telephone. It is easier to recognize DISCRETE SPEECH (speech with pauses between words) than CONTINUOUS SPEECH, but discrete speech is slow and awk- ward. Hesitation noises (“uh,” “um”), coughs, and sneezes are some- times mistaken for words. speech synthesis the generation of human-like speech by computer (by com- puting the pronunciation of each word, not by playing back recordings). Originally handled by special hardware, speech synthesis is now usu- ally done by means of software running on a personal computer with a sound card. The technology to generate understandable speech has existed since the 1960s, but the speech is not completely natural; the intonation and timing are not perfect, and the voice may be monotonous and robot-like. Speech synthesis is important in making computers accessible to blind people and delivering computer data by telephone. A speech syn- thesizer is built into Windows. spell checker, spelling checker a program that checks the spelling of every word in a document by looking up each word in its dictionary. Many word processors do this as the words are typed. If the word does not appear in the dictionary, the user is alerted to a possible misspelling, and possible corrections are often suggested. Sometimes the correction will be made automatically, but you need to double-check to make sure that the resulting word is correct. A spell checker will not recognize unusual proper names or special- ized terms, but it will often allow you to create your own personal dic- 449 spell checker, spelling checker 7_4105_DO_CompInternetTerms_S 12/29/08 10:37 AM Page 449 tionary of specialized words you often use. (Be sure not to put mis- spelled words into it!) Spell checkers are valuable aids to proofreading, but they cannot catch the substitution of one correctly spelled word for another (such as form for from or to for too). Thus they do not guarantee that a document is free of spelling errors. spider a program that explores the World Wide Web; a CRAWLER. SPIM a SPAM message sent by instant messaging. spin button a dialog box element that allows the user to change numbers rapidly by clicking on the up and down arrows or by typing the desired number directly into the number box. FIGURE 245. Spin button spindle count in a disk or file sharing system, the total number of actual disk drives (each with a stack of magnetic disks revolving around a sin- gle spindle). splash screen a screen display or small window that appears briefly while a program is starting up, displaying its name, trademark, and version information. spline a curve that connects a set of points smoothly. Figure 246 shows some examples. For details of computation, see B-SPLINE; BÉZIER SPLINE; CUBIC SPLINE. FIGURE 246. Splines (3 types) sploit (slang; plural sploitz) an EXPLOIT; a way of breaching the security of a system. spoofing the act of impersonating a user or a machine. For example, IP spoofing is the act of attaching a computer to the Internet using an IP ADDRESS assigned to a different computer, thereby intercepting com- munications intended for the other machine. See PHISHING. spider 450 7_4105_DO_CompInternetTerms_S 12/29/08 10:37 AM Page 450 spooling the process of storing computer output before sending it to the printer. See PRINT SPOOLER. spot color the use of a specified color of ink in a printing job. Spot color can be used for emphasis or to add interest to documents. Contrast PROCESS COLOR. These terms apply to mass-production printing with a printing press, not to inkjet or laser printers attached directly to computers. spray can a tool found in various paint programs that leaves a circular pat- tern of the selected color. To use it, you press and hold down the mouse button and drag the mouse. The center of the spray pattern will be solid, but the edges will feather out to the background color. If you need a dense, solid color, move the mouse slowly; if you want a wispy trace of color, move the mouse rapidly. You can change the size of the spray can’s coverage area—usually by changing the brush size. A similar tool is the AIRBRUSH. Generally, a program will have either an airbrush or a spray can tool, but not both. FIGURE 247. Spray can spread-spectrum a technique of radio transmission in which the frequency changes many times per second in a predetermined but seemingly ran- dom sequence. The receiver knows the sequence and follows the fre- quency changes. Spread-spectrum transmission overcomes interference because two transmitters will never be on the same frequency for more than a moment. Spread-spectrum transmission also provides privacy because the signal is almost impossible to intercept without knowing the sequence of frequency changes. See WIRELESS COMMUNICATION. spreadsheet a table of numbers arranged in rows and columns. Paper spreadsheets were used for business data long before computers were invented. The first computer spreadsheet was VisiCalc, used on the Apple II computer in the late 1970s. Recently the most popular spreadsheets has been Microsoft Excel. Here are some general features of these programs: 1. Data is arranged in rows (labeled with numbers) and columns (labeled with letters). Each location in the spreadsheet is called a cell. You can enter numbers or letters in a cell, as in this example, which records the sales of different types of products at a small store: ABC D 1 Item Price Quantity 2 cereal 3.99 10 3 milk 2.15 25 4 toothpaste 1.95 7 451 spreadsheet 7_4105_DO_CompInternetTerms_S 12/29/08 10:37 AM Page 451 2. The computer will do calculations automatically if you enter for- mulas. For example, to calculate the revenue from the sale of cereal, enter the formula =B2*C2 in cell D2. (The asterisk * repre- sents multiplication; the initial equal sign indicates this is a for- mula and not a label. When a formula is entered, the spreadsheet will display the result of the formula, not the formula itself, in that cell. However, mov- ing the cell pointer to a cell will let you see the formula for that cell at the top of the screen, and you can edit it if needed. 3. A formula in one cell can be copied to other cells. For example, the formula in cell D2 can be copied to cells D3 and D4, which will give the total revenue for the other products: The copy command automatically changes formulas when they are copied to new cells. In the preceding example, when you copy the formula =B2*C2 from cell D2 to cell D3, it will become the formula =B3*C3, and in cell D4 it will become =B4*C4. This is because B2 and C2 in the formula in the original cell (D2) were written in the form of a RELATIVE ADDRESS. See ABSOLUTE ADDRESS to learn how to prevent the cell addresses from being changed by the copy command. 4. A formula can contain built-in functions, such as a command to sum all cells in a range. Entering Excel formula =SUM(D2:D4) into cell D5 will automatically calculate the column total (cells D2, D3, and D4). Many such functions are included with spreadsheet pro- grams. 5. Spreadsheets are especially valuable because the formulas will be automatically recalculated whenever one of the numbers is changed. For example, if later in the month you update your sales figures, the program will automatically recalculate the revenue for ABC D 1 Item Price Quantity Revenue 2 cereal 3.99 10 39.90 3 milk 2.15 25 53.75 4 toothpaste 1.95 7 13.65 ABC D 1 Item Price Quantity Revenue 2 cereal 3.99 10 39.90 3 milk 2.15 25 4 toothpaste 1.95 7 spreadsheet 452 7_4105_DO_CompInternetTerms_S 12/29/08 10:37 AM Page 452 [...]... logarithm of each of the elements in a list), and for drawing graphs of the data Examples of statistics programs include SAS (Statistical Analysis System) and SPSS (Statistical Program for the Social Sciences) status line a line of information on the computer screen that indicates the current settings of the software and the current cursor position The contents of a status line will vary depending on the software... type of Ethernet coaxial cable See 10BASE-2 third-generation computers the first generation of computers made with integrated circuits third party someone other than the maker of a machine and the END USER For example, third-party software is software that does not come from the manufacturer of the computer, nor is it developed by the user Most software today is third-party software 7_4105_DO_CompInternetTerms_T... download and install software on your computer automatically (see ACTIVEX) Current versions of Windows ask for permission before installing software, but it is very important for the user to be alert and not give this permission inappropriately Above all, do not click on web site buttons that offer to do anything to your computer, such as check it or “optimize” it Software tools for detecting and removing... 7_4105_DO_CompInternetTerms_S 12/ 29/ 08 10:37 AM Page 458 458 Storm worm originated by Charles Babbage in the 19th century and was developed by John Von Neumann The ability of a computer to store instructions allows it to perform many tasks without human intervention The instructions are usually written in a programming language See COMPUTER Storm worm a WORM virus introduced in 2007 that linked thousands of computers... emphasizes clear logic, modularity, and avoidance of GO TO statements (which are intrinsically error-prone) One of the most important barriers to the development of better computer software is the limited ability of human beings to understand the programs that they write Structured programming is a style of programming designed to make programs more comprehensible and programming errors less frequent... database, and a spreadsheet The advantage of using a suite is compatibility; you are assured that all of the programs can accept data from any of the others and incorporate them in their own files On the downside, the individual programs of a software suite sometimes lack desirable features If additional software is purchased, it may be difficult to get the programs to work together 7_4105_DO_CompInternetTerms_S... and input-output devices of a computer while leaving the contents of memory in place, so that it can resume where it left off without rebooting Unlike a hibernating computer, a suspended computer continues to consume a small amount of battery power Contrast HIBERNATE 7_4105_DO_CompInternetTerms_S 12/ 29/ 08 10:37 AM Page 465 465 switch SVGA (Super VGA) a video resolution of 800 × 600 pixels Contrast... processors and compilers, and data file management programs Systems programming requires considerable knowledge of the particular computer system being used Contrast APPLICATIONS PROGRAMMER 7_4105_DO_CompInternetTerms_T 12/ 29/ 08 10:38 AM Page 468 468 T1 line T T1 line a special type of telephone line for digital communication only, with a maximum data rate of 1.544 million bits per second Many Internet. .. interface It is one of the easiest ways to do GUI programming under UNIX, and implementations for Microsoft Windows also exist TCL/TK is an open-source project, and most implementations of it are distributed free of charge For more information, see www.scriptics.com TCO (total cost of ownership) the complete cost of owning and using a machine during its useful life, including not only the cost of the machine... be automated; you should be able 7_4105_DO_CompInternetTerms_T 12/ 29/ 08 10:38 AM Page 474 474 Texas Instruments just to give the title of a chapter, and let the computer take care of numbering the chapter and putting the title in the right place on the page Most TEX users access TEX through LATEX, a package of ready-to-use document designs and command shortcuts that make the system easier to use See . cereal 3 .99 10 39. 90 3 milk 2.15 25 53.75 4 toothpaste 1 .95 7 13.65 ABC D 1 Item Price Quantity Revenue 2 cereal 3 .99 10 39. 90 3 milk 2.15 25 4 toothpaste 1 .95 7 spreadsheet 452 7_4105_DO_CompInternetTerms_S. of vocabulary, recognition of key phrases, and identification of known spam sites. To try to get around spam filters, spammers misspell the names of products and often include large numbers of. special- ized terms, but it will often allow you to create your own personal dic- 4 49 spell checker, spelling checker 7_4105_DO_CompInternetTerms_S 12/ 29/ 08 10:37 AM Page 4 49 tionary of specialized