GLOSSARY The glossary defines terms common to all of the MiniMINC manuals. A term is defined here if its use in the MiniMINC man- uals deviates from its standard dictionary definition. Algorithm A fixed series of well-defined procedures that solves a problem in a finite amount of time. Programmers generally construct an algo- rithm as an outline for writing a new program. Analog Relating to the representation of a physical attribute such as volt- age by an analogous phenomenon, such as the deflection in a graph. Application - The particular task or set of related tasks for which you use a computer. Application program A program that performs a task specific to your needs. Usually, ap- plication programs are those programs not part of the system itself. Argument A variable or constant value or expression used with a command, statement, or routine that controls its action, specifically its loca- tion, direction, or range. An argument can also be any variable or constant value used by a function. Array An ordered arrangement of subscripted variables derived from a common variable. For instance, an array J might contain the sub- scripted variables J (0),J (1),J (2), and J (3). 75 GLOSSARY ASCII The American Standard Code for Information Interchange; a standard code for upper- and lower-case letters, numbers, punc- tuation, and special communication control characters. Assembly language A symbolic programming language that normally translates di- rectly into a machine language. Autoscaling A MiniMINC feature that automatically adjusts the axis units of a graph to the minimum and maximum numerical values of a set of data. Bad Block A damaged block existing on your volume that the system cannot access. Blocks become damaged from wear or abuse. BASIC Beginner’s All-purpose Symbolic Instruction Code; BASIC is an interactive, "algebraic" type of computer language developed at Dartmouth College, Hanover, N .H., by Kemeny and Kurz that combines English words and decimal numbers. It is a widely available, standardized, simple beginner’s language capable of handling industrial, laboratory, and business applications. MINC BASIC is a special version of this standard language. Binary The number system with a base of two, used by the internal logic of most digital computers. Block A unit of space, or capacity, on a storage volume. A block can hold 512 characters. Branching A programming technique that transfers control to a program statement independent of its sequence in the program. Branching allows you to construct programs containing specialized parts that execute only if a particular condition exists. Brand A small vertical line on a graph used to mark the exact horizontal location of data. Bug Any error existing in a program. Chain A connected series of separate programs or program parts. Chain- ing is the simplest way in MiniMINC to prepare separate pro- grams for parts of a complex task and then run them together. Channel A logical pathway used in MINC BASIC for the sending and re- ceiving of data. There are 12 MiniMINC file channels available through the OPEN statement that allow programs to access files for data. 76 GLOSSARY Character mode The stylistic features shared by characters appearing on a ter- minal screen. MiniMINC character modes consist of boldface, un- derline, reverse video, flashing, or normal elements. You can spec- ify character modes alone or in combination. Column C The vertical position on the MiniMINC terminal screen in which a character is displayed. Compare with Row. Command A word, mnemonic, or character which, by virtue of its syntax and its position in an input line, causes a computer to perform a prede- fined operation. In MINC BASIC, commands can be used only in immediate mode. Compile To convert an ASCII file into its smaller binary form. A compiled MINC BASIC program requires less storage space and less time for handling by MiniMINC. Computer An electronic device that stores, retrieves, and processes data through the execution of programmed instructions. Computer system A combination of devices, programs, and documentation designed for automatic problem solving following or concurrent with hu- man intervention. Concatenation The joining of two strings of characters to produce a longer string. Conditional branch Branching within a program that involves testing for a condition before executing some statement or series of statements. Conditional transfer The action resulting from a conditional branch. Constant An invariable and unchanging value. Compare with variable. Control character The product of pressing the CTRL key and a letter key on the MiniMINC keyboard simultaneously. A control character some- times appears on the terminal screen as a caret (A) next to the ap- propriate letter. Control command A command that alters a current user or computer activity. Unlike other commands that work only when READY is displayed on the screen, you can give a control command at almost any time to es- tablish your "control" over the computer. Cursor A unique symbol that marks your current position on a video ter- minal screen. Whatever character you type will appear at the cur- sor. With the MiniMINC terminal, you can use either a flashing 77 GLOSSARY box or a flashing underscore as the cursor symbol. Data A term used to denote any or all facts, numbers, letters, and sym- bols forming basic elements of information that can be processed by a computer. Debug To detect, locate, and correct errors in a program. Default An option or argument value assumed by a program if a specific value is not supplied by the user. Define To assign a value to a variable or to assign an expression to a user function. Device A piece of equipment such as a line printer or diskette drive unit. Digital A A term referring to numbers represented as discrete units. A digi- tal computer interprets electronic signals as discrete digits (0 or 1), while an analog computer interprets them as analogs of a wider range of numbers. Directory A table that contains the name, size, and location of every file on a mass-storage volume. Diskette A thin, flexible, magnetic, oxide—coated disk resembling a 45 rpm record and permanently enclosed in an 8-inch square envelope. Diskettes are random-access, mass-storage volumes. Display mode An attribute of the entire terminal screen. MiniMINC display modes determine the background color of the screen, the width of character lines, and the scrolling method. Distribution medium Any volume or material used in distributing copies of system pro- grams. Distribution media are generally diskettes or magnetic tape. Drive A unit that holds and manipulates a mass-storage medium such as a diskette or magnetic tape. Dummy argument An argument inside the definition of a function that holds the place for the formal argument. E notation Method of representing numbers in MiniMINC greater than 999999 or less than .01. The letter E appears between the mathe- matical expression and the exponent in lieu of the "x 10" used in sci- entific notation. 1.0x10`4 becomes 1.0E-4 in E notation. 78 GLOSSARY Edit To arrange and/or modify the format of data and programs, in- cluding insertion and deletion of text. Editor The program you use to create and edit files within a com- puter} Editors manipulate characters without regard for their ‘ significance. Element The smallest unit of storage within an array For example, N(12) represents an element in the array N. Error message A brief message MiniMINC displays on your terminal when an er- ror occurs. Error messages identify the nature of user and com- puter errors and sometimes suggest a corrective action. Execute To carry out an instruction or run a program on the computer. Expression A combination of variables, constants, and operators (as in a math- ematical expression). Field A specified area of a mass-storage volume, statement, command, or terminal screen used for a particular category of data. File A logical collection of data treated as a unit, which occupies one or more blocks on a mass-storage volume, and has an associated file name and type. . File allocation The MiniMINC practice that determines the placement of a file on a diskette. The MiniMIN C system stores a file in the first available area that is large enough to hold the file. In some cases, MINC BASIC requires that the available space be twice as large as the file before allocating space. File Number A channel number associated with a file that you use when refer- ring to the file within a program. File spec See File specification. File specification The part of a command or statement that identifies a file’s name and type and the device where it can be found. File Type The one-to-three character string assigned to a file either by the user or the computer. The file type follows the file name and is pre- ceded by a period. The file type serves to further identify the kind of file as in PRGRAIVLBAS where PRGRAM is a BASIC program. Flow (of control) The order in which a program’s statements are executed. 79 GLOSSARY Form Feed An ASCII character that delimits pages within a file. On some printing equipment, a Form Feed causes a skip to the next page. Formatting An ungrammatical term that has come to mean the recording of _ timing information on magnetic, mass-storage volumes. The tim- ing information is necessary for drive units to be able to find infor- mation stored on the volumes, Function A subprogram that performs commonly used operations (for ex- ample, the square root calculation function). The name of the func- tion takes on the value of the calculation and can be used as a pro- gram variable. Some functions exist as part of MiniMINC and others can be user—defined. Graph number A label (0,1, or 2) used in graphic routines to specify each graph individually or both in a two—graph display. Graph region The portion of a terminal screen reserved for graphic display MiniMINC has three graph regions: upper, lower, and full screen. Graphic memory The memory area of a MiniMINC terminal that preserves graphic data. The graphic memory allows you to display the same data in more than one graphic format. Graphic program Programs that compute data and construct diagrams for the display of that data on a graphic display terminal. Graphic routine A statement that performs a routine task associated with graphic display High-level language A programming language (for example, BASIC, FORTRAN, and COBOL) whose statements are problem-oriented and typically translated into more than one machine language instruction. Immediate mode The mode in which a computer executes statements as soon as you type them, without requiring a program. Infinite Ioop A program segment that, when executed, repeats endlessly be- cause it lacks any provision for termination. Initialize To prepare a new mass-storage volume for use with a computer or to erase a used volume in preparation for reuse. Initialization sets up an empty file directory on a volume. Input The act of placing information inside a computer, or the informa- tion itself. 80 GLOSSARY Integer variable A variable representing only whole numbers within some range (for example, -32768 to +32767). Intelligence The capacity of a machine for mimicking activity, such as reason- ing or learning, normally attributed to human intelligence. e Interlacing A feature of the MiniMINC terminal. Interlacing is the placing of additional scan lines between the normal ones in the terminal’s screen. This increases character density by reducing the amount of undefined space within each character. Interlacing is useful whenever you photograph the screen. Left-justified An arrangement of text where every line begins at the same dis- tance from the lefthand margin. Line A string of characters terminated with a vertical tab, form feed, or line feed/ carriage return combination. » Line printer A printing device that composes a line of characters before print- ing it. The term is sometimes erroneously used to mean a character printer. Literal A language element that permits the explicit representation of values in expressions. In most languages, a character string literal is enclosed in single or double quotes, while a numeric is not. In either case, the value is what it appears to be, not the name of a value. Load 1. To insert a program or data into memory. 2. To place a removable disk in a disk drive and start the drive. Logical expression An expression having one of two possible values-true or false. Loop A sequence of programming statements that, when executed, re- peat continuously until an end condition is met. Machine language The binary language used by a computer when performing operations. Mass storage Pertaining to a volume that can store large amounts of data readily accessible to the computer. Master volume A single-purpose, mass-storage volume dedicated to the creation of system, demonstration, and user volumes. Memory The part of a computer that temporarily stores programs and data 81 GLOSSARY intended for immediate use. Mixed mode Arithmetic operations involving a combination of integer and real operands. Modem A modulator/demodulator apparatus that permits long distance transmission of digital data. Multiple branch A program statement that transfers program control to one of sev- eral possible locations. Multiway branch Same as a multiple branch. Nesting Including an executable operation within a larger one of the same or similar type. BASIC allows you to override operator priorities (A , * , / , + , - descending order from left to right) bynesting expres- sions with parentheses. BASIC also allows nesting of program- ming loops, where the internal loop must be totally contained within the external loop. Nonprogram file A sequential or virtual array file containing anything but a program. Nonsystem volume A volume capable of storing programs and data, but lacking the structure and programs necessary for starting and maintaining the system. Null An ASCII character whose numeric code is 0. Numeric variable A computer storage location reserved for a numeric value. Octal Pertaining to the number system with a base of 8. One-dimensional array An array with one subscript. Operation The act specified by a single computer instruction. A program step undertaken or executed by a computer (addition, comparison, and multiplication, for example). Option An element of a command, command string, statement, or rou- tine that enables you to select from among several associated alternatives. Output 1. The result of a process. 2. The transfer of data from internal to external storage or to the terminal screen. 82 GLOSSARY Overlay The practice of merging a program segment with statements ex- isting apart from that segment. Owner name Name indicating ownership of a volume. The user assigns this name to a volume during its initialization or its adaptation by a A master volume. The owner name appears whenever the user re- quests a volume’s directory. Page That portion of a text file delimited by form feed characters and generally 50-60 lines long. Plotter A device using an automatic pen or pencil to construct visual rep- A resentations of data. Plotters sometimes receive plotting coordi- nates from digital computers. Point A single data value. Precision The resolution of a number’s representation by a computer. MiniMINC’s precision extends to six significant digits for real numbers and four (plus) digits for integers. Print zone An assumed horizontal subdivision of the terminal screen. MiniMINC acts as though the terminal’s screen is divided into five print zones of 14 columns each, skipping to the next zone whenever it encounters a comma in a PRINT statement. Program A set of computer instructions or symbolic statements combined to perform some task. Program file A program stored on a volume. A program file has a file name and type. Program flow The order in whicha program’s statements are executed. Also known as flow of control. Programming language A computer-oriented language used in writing programs. Prompt A word or message printed by the system that requests or suggests some action on your part. Random access Access to data in which the next location from which data is to be obtained does not depend on the location of the previously obtained data. Diskettes are examples of random access storage media. Contrast with Sequential access. Raster unit A fixed unit of linear measure used in determining bar width for 83 GLOSSARY MiniMINC bargraphs. The MiniMINC terminal screen measures 240x512 raster units. Read To copy data from one form of storage to another, usually from an external device to internal storage such as memory. Real number Commonly understood to be any positive or negative number, ex- cluding imaginary or complex numbers. However, computers im- pose limits on the range (approximately .29x10T38 through 1.7x10+38) and precision of real numbers. Consequently, all irra- tional and many rational numbers are excluded from the working definition of a real number. Real variable A variable for real numbers. Relational operator A symbol representing the relationship of one value to another. The relational operators in AMINC BASIC are = (equal to), < (less than), < I (less than or equal to), > (greater than), >= (greater than or equal to), and < > (not equal to). Right-justified An arrangement of text where every line ends at the same distance from the right—hand margin. Routine A statement that performs some routine task. Routines return their results through arguments, unlike functions that return values within their names. Row The horizontal strip on the terminal screen in which a line of text A can be displayed. The MiniMIN C terminal has 24 rows. Text coor- dinates are given in rows and columns, whereas graph coordinates use X and Y Run To execute a program. Save To store a program or data as a file on a volume. Information not saved is erased when you shut off the computer or use MiniMINC’s workspace for another operation. Scientific notation Method of representing real numbers as a number from 1-10 multiplied by an appropriate power of 10. For example, 56930 be- comes 5.693x 104 in scientific notation. See E notation. Scrolling The upward movement of data on a terminal screen to accommo- date new data. The oldest line of data disappears from view at the top of the screen when the new line appears at the bottom. Scrolling area The region on a terminal screen where scrolling takes place. The 84 GLOSSARY scrolling area normally occupies 24 rows. Search In MiniMINC, the keypad editor’s examination of a file or part of a file for a designated string. Search model The string you type as the object of a search. - Sequential access Access to data in which the next location from which data is to be obtained sequentially follows the location of the previously ob- tained data. Contrast with Random access. Sequential file A file that must be accessed sequentially MiniMlNC looks for in- formation in a sequential file by checking one position after an- A other in a linear direction. Serial A mode of data transmission in which the components of each data word are transmitted according to a prescribed protocol, one after another (serially) along a single pair of lines from a sending to a receiving device. Serial line unit One of six ports on the back of the chassis dedicated to hookups with serial line devices. Such devices include your terminal and printers. Often referred to as an SLU. SLU Same as a Serial line unit. Statement An element of a program. Programs are sequential arrangements of statements. Storage medium Any type of sequential-access or random-access volume used for storing files. String A connected sequence of characters. String variable A variable used for any ordered collection of numeric, alphabetic, and special characters up to 255 in length. Strip chart mode The dynamic display of data in graphic form. This MiniMINC fea- ture lets you see a large number of points plotted in a continuous flow across the screen, resembling the action of a strip chart. Also called move mode. Subroutine A group of statements arranged within a program so that pro- gram control can pass to the subroutine and back to the program again. Subroutines usually perform tasks required more than once by the program. 85 GLOSSARY Subscript A number appended to a variable name to uniquely identify spe- cific elements of an array Subscripts are enclosed in parentheses. Substring Any contiguous part of a larger string. System file Any one of a group of files containing the programs and data that, together with the equipment and documentation, comprise a com- puter system. System volume The storage medium that contains the system files. Syntax The structure of expressions in a language and the rules governing that structure. Terminal The primary communication device between you and the computer system. A terminal has a keyboard and a display mechanism. Timesharing A method of allocating resources to multiple users so that the com- puter, in effect, processes a number of programs concurrently Tone The sound signal emitted by the MiniMINC terminal whenever an editor operation fails or you type to the end of a line. Two-dimensional array An array requiring two subscripts (commonly portrayed as a matrix). Unconditional branch A programming technique that transfers program control to the statement you specify without regard for sequence. Unconditional transfer Same as Unconditional branch. User volume The storage medium reserved for user files and the HELP text file. Variable 1. A computer storage location that can contain a value that A changes during computation. 2. The symbolic representation of a variable (for example, F, F%, and F$). Virtual array file A file containing information directly accessible by MiniMINC. The system can retrieve any piece of data without first examining the information preceding it. The file is virtual because it ap- pears in the program as an array even though it is a file stored on a volume. 86 GLOSSARY Vol id See Volume identifier. Volume A logical storage medium — but not any particular one. A generic term used for general reference. Volume identifier (Vol id) Identifying name assigned to a volume by a user during the volume’s initialization or its adaptation by a master volume. The volume identifier appears whenever the user requests a volume’s directory. Window The relationship for a single graph that defines placement of coor- dinates at physical screen positions, so called because the graph is like a window through which you view a portion of the X-Y coordi- nate space. Word The number of characters treated as a unit in the workspace. MiniMINC words can contain 2 characters, 1 integer, orone half of a real number. Workspace MiniMINC’s storage area for temporarily holding a program you type and its associated values. Wrap symbol The two-character, symbol displayed by the keypad editor when- ever a file line is longer than a screen row. Indicates that the pre- ceding line does not end with a line terminator. Wrapped line Any line that is continued onto the next row because it is too long to fit in a single row. Write To copy data from internal storage to an external device or to in- sert data into a storage location. 87