Structured approachThe movement from a logical design to a physical design fol­lowing a set pattern of steps. Also called top-down approach.

structured decisions Decisions that can be programmed in advance.

structured program A program using the processing block, the repetition block, and the decision block with no transfers into, out of, or between blocks.

structured walkthrough A part of the sys­tems analysis and design process in which the analyst presents the current status of the process to his or her peers.

stylesheet An operation of the desktop pub­lishing package that specifies the format of a document.

subdirectories Subgroups of files, each of which is assigned a name.

subprograms In top-down design, smaller, manageable sections of a program that can be written separately and then reu­nited.

subroutine A section of a program that car­ries out a specific operation; another name for a module in a top-down-designed program.

supercomputer The biggest, fastest com­puters used today.

superconductivity The ability of certain materials at low temperatures to conduct electricity without resistance.

supervisor program The major unit of the operating system that resides in internal memory at all times to manage the load­ing of other parts of the operating system and the applications programs.

surge protector A device that protects the computer's hardware and memory from a voltage surge.

symbol processor A computer that can manipulate symbols as well as numbers; another name for a computer.

synchronous communications A form of communication between computers that does not require the computers to be syn­chronized and allows large numbers of characters to be sent as a block.

syntactical (grammatical) form In pro­gramming, the syntax that must be fol­lowed in the writing of the programs.

syntax error In a computer program, an error in the syntax or vocabulary of the program.

system A group of elements organized for the purpose of achieving a particular goal.

system bus A communications system that allows the transfer of instructions, data, and control commands among the control unit, the arithmetic-logic unit, and the internal memory unit.

system command In BASIC, a command that results in some action by a program.

system design The fourth step in the sys­tems analysis and design process, in which the analyst develops a high-level design of the new system that includes its actual parts.

system disk The disk that contains the operating system.

system interrupt A command from the operating system for the current job to be temporarily interrupted so another job can be executed.

systems analysis and design process The process of developing a system design to meet a new need or to solve a problem in an existing system.

systems analyst The person who carries out the systems analysis and design process.

systems audit software Security software that keeps track of all attempts, especially unsuccessful ones, to log on to the com­pany's computer system.

systems development life cycle See sys­tems analysis and design.

systems flowchart A special type of flow­chart that demonstrates the flows of infor­mation and control in the existing system.

systems life cycle See systems analysis and design.

systems programmers Programmers that maintain mainframe operating systems.

systems software The programming that controls the operations of utility software and applications software.

table A group of numbers or strings orga­nized into rows and columns.

tactical decisions Decisions made by mid­dle-level managers using summary reports. These are not easily programma­ble.

tape See magnetic tape.

tape cartridge Storage medium used by personal or mainframe computers to back up hard disks.

tape drive An electronic device that uses a read/write head to transfer information to and from magnetic tape.

target marketing The process by which advertisers use data banks to select a group of individuals who are most likely to buy their products, thereby allowing advertisers to spend more time and money on fewer prospects.

tax planning and preparation package A package used to keep track of tax records throughout the year and to determine the effects of financial decisions.

telecommunications The combining of a computer with a communications link, a modem, and appropriate communications software to become a communications tool.

telecommunications software A group of programs allowing a personal computer user to communicate with other people, computers, and data bases.

telecommuting The process of working at home using either a personal computer or a terminal tied into a mainframe.

template A skeleton spreadsheet that matches a particular application but does not include the data.

temporary variable A variable that is used to store a value temporarily.

terminal A keyboard and a monitor con­nected to a computer. (Also see computer terminal)

terminal emulation A hardware/software combination that allows a personal com­puter to work like a dedicated mainframe terminal.

terminal symbol In flowcharting, an oval shape that is used to start and end all flowcharts.

terminalitis Musculoskeletal problems resulting from extensive use of a VDT.

test data Data that are used in hand calcu­lations to determine in advance the results expected from the program.

text editing The word processing function that allows material to be changed, inserted, or deleted from existing text.

text files Materials stored on files in the form of readable text, as opposed to binary.

thermal printer A nonimpact printer that uses a matrix of heated wires to form symbols on special paper.

thesaurus An editing tool that provides synonyms and antonyms for specified words.

time bomb A computer crime in which a disruptive program is timed to execute itself on a certain date.

time slice A small fraction of the total exe­cution time that is allocated to a terminal in a time-sharing system.

token A special bit pattern used in a token-sharing local area network to determine which user can transmit information.

token/sharing network A local area net­work in which a bit pattern called a token is used to determine which user on the network can send information.

top-down approach See structured approach.

top-down design An approach to writing structured programs that breaks the pro­gram up into blocks or modules to be written individually and then combined into the final program.

touchscreen An input device wherein the user simply touches a part of the screen to enter information.

trackball A device to move a cursor. The user rolls a plastic ball with his/her fin­gertip or wrist.

track Parallel magnetic lines, running the length of magnetic tape, on which infor­mation is stored; also, concentric regions on a magnetic disk.

trailer record A special data record that signals the end of data to an INPUT loop.

transaction log tape A tape that contains a copy of each transaction that is processed on disk storage.

transaction processing system (TPS) Con­verting raw data into a usable, electronic form.

transaction screen A screen on which the user enters actual income and expenses.

transactional data Data that are created when a transaction takes place that requires the customer to reveal his or her identity.

transactional processing Data are proc­essed as they occur at the time of entry— e.g., grocery checkout systems.

transfer The return to the beginning of a loop that starts the repetition again.

transistors Solid-state elements on a chip that carry out the control and logic opera­tions.

transmission time The actual time needed to transfer data to or from a disk.

trapdoor A part of the operating system that will allow knowledgeable users unau­thorized access.

tree structure See hierarchical structure.

Trojan horse A computer program that sabotages the original program or modi­fies it to perform illegal activities.

turtle A graphics character used in the LOGO computer language.

two-alternative decision A decision in which one set of actions is taken if the condition is true and another set of actions is taken if the condition is false.

two-dimensional array A table of numbers or strings.

type-ahead buffer A keyboard's ability to store data typed by the user that the com­puter is not ready to accept.

typeover mode See replace mode.

unblocked record A physical record that corresponds to one logical record.

uninterruptible power supplies (UPS) A device that continues power to a personal computer if the electrical current is dis­rupted.

UNIX Originally developed for use on min­icomputers, a multiple-machine, multitask­ing generic operating system converted to work on PCs.

unstructured decisions Decisions that can­not be programmed in advance.

uploaded The process of shifting software or data from a personal computer to a central computer.

upper memory The 384 bytes above con­ventional memory up to 1 Mbyte. Upper memory is normally reserved for software that is required for hardware devices, such as monitors or network linkages.

user friendly A software package that is easy to use.

user interface Allows the software user to enter data and commands. The three most common are menu driven, command driven, and graphical.

user prompt In BASIC, a string constant that is included in the INPUT statement to prompt the user to enter the needed data.

user-defined function A specific numerical or string operation in BASIC that is defined by the user.

user's manual A set of directions for the use of software packages.

utility software Software that controls the computer's day-to-day housekeeping oper­ations.

value A number, either positive or negative, with or without a decimal.

value-added network (VAN) Public net­works available by subscription to provide clients with data communications facili­ties.

variable The name for a memory cell used in writing a program.

variable expense Expense that tend to fluc­tuate from month to month.

variable-length word A word that com­bines as many bytes as necessary to rep­resent a symbol.

verification The process of comparing cor­rect information to the information on punched cards, tape, or disk.

video disk A read-only form of secondary storage using a laser or an optical disk.

video display terminal (VDT) Any per­sonal computer or terminal tied into a mainframe that uses a cathode ray tube (CRT) to echo input and display output.

Video Graphics Array (VGA) An analog graphics adaptor that will display 256 col­ors in 640 X 480 resolution as well as displaying high-quality text.

video page The amount of word processing text that can actually be seen on the screen.

videotex The process of shopping, banking, or managing stocks and bonds from the home using a computer and a communi­cations link.

virtual memory The use of disk drives to give the appearance of increased internal memory.

virtual reality Input devices dependent on artificial intelligence that seek to make computer and human interaction transpar­ent in order to create a custom universe within a computer

virus A computer program whose purpose is to replicate itself, with mischievous or malicious intent, within the computer's memory.

voice-grade transmissions A slow type of information transmission that generally uses twisted pairs as a media device.

voice mail Allows the user to send, receive, store, and relay spoken messages.

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