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Line Number
In computing, a line number is a method used to specify a particular sequence of characters in a text file. The most common method of assigning numbers to lines is to assign every line a unique number, starting at 1 for the first line, and incrementing by 1 for each successive line. In the C programming language the line number of a source code line is one greater than the number of new-line characters read or introduced up to that point. Programmers could also assign line numbers to statements in older programming languages, such as Fortran, JOSS, and BASIC. In Fortran, not every statement needed a line number, and line numbers did not have to be in sequential order. The purpose of line numbers was for branching and for reference by formatting statements. Both JOSS and BASIC made line numbers a required element of syntax. The primary reason for this is that most operating systems at the time lacked interactive text editors; since the programmer's interface was usually limit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, engineering, mathematical, technological and social aspects. Major computing disciplines include computer engineering, computer science, cybersecurity, data science, information systems, information technology and software engineering. The term "computing" is also synonymous with counting and calculating. In earlier times, it was used in reference to the action performed by mechanical computing machines, and before that, to human computers. History The history of computing is longer than the history of computing hardware and includes the history of methods intended for pen and paper (or for chalk and slate) with or without the aid of tables. Computing is intimately tied to the representation of numbers, though mathematical conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assembler Language
In computer programming, assembly language (or assembler language, or symbolic machine code), often referred to simply as Assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence between the instructions in the language and the architecture's machine code instructions. Assembly language usually has one statement per machine instruction (1:1), but constants, comments, assembler directives, symbolic labels of, e.g., memory locations, registers, and macros are generally also supported. The first assembly code in which a language is used to represent machine code instructions is found in Kathleen and Andrew Donald Booth's 1947 work, ''Coding for A.R.C.''. Assembly code is converted into executable machine code by a utility program referred to as an ''assembler''. The term "assembler" is generally attributed to Wilkes, Wheeler and Gill in their 1951 book ''The Preparation of Programs for an Electronic Digital Com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Level I BASIC
Level I BASIC is a dialect of the BASIC programming language that shipped with the first TRS-80, the TRS-80 Model I. Background Tandy-employee Steve Leininger had written the first draft of the NIBL (National Industrial Basic Language) BASIC interpreter for the SC/MP while employed at National Semiconductor . Unable to take that source code with him, he initially hired a consultant to write an interpreter. When that contractor failed to deliver, he adapted Li-Chen Wang's public domain version of Tiny BASIC for the original prototype of the TRS-80 Model I. This required only 2 KB of memory for the interpreter, leaving an average of another 2 KB free for user programs in common 4 KB memory layouts of early machines. During a demonstration to executives, Tandy Corporation's then-President Charles Tandy tried to enter his salary but was unable to do so. This was because Tiny BASIC used 2-byte signed integers with a maximum value of 32,767. The result was a reques ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integer BASIC
Integer BASIC is a BASIC interpreter written by Steve Wozniak for the Apple I and Apple II computers. Originally available on cassette for the Apple I in 1976, then included in ROM on the Apple II from its release in 1977, it was the first version of BASIC used by many early home computer owners. The only numeric data type was the integer; floating-point numbers were not supported. Using integers allowed numbers to be stored in a much more compact 16-bit format that could be more rapidly read and processed than the 32- or 40-bit floating-point formats found in most BASICs of the era. This made it so fast that Bill Gates complained when it outperformed Microsoft BASIC in benchmarks. However, this also limited its applicability as a general-purpose language. Another difference with other BASICs of the era is that Integer BASIC treated strings as arrays of characters, similar to the system in C or Fortran 77. Substrings were accessed using array slicing rather than string function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BASIC-PLUS
BASIC-PLUS is an extended dialect of the BASIC programming language that was developed by Digital Equipment Corporation (DEC) for use on its RSTS/E time-sharing operating system for the PDP-11 series of 16-bit minicomputers in the early 1970s through the 1980s. BASIC-PLUS was based on BASIC-8 for the TSS/8, itself based very closely on the original Dartmouth BASIC. BASIC-PLUS added a number of new structures, as well as features from JOSS concerning conditional statements and formatting. In turn, BASIC-PLUS was the version on which the original Microsoft BASIC was patterned. Notable among the additions made to BASIC-PLUS was the introduction of string functions like and , in addition to Dartmouth's original all-purpose command. In future versions of the language, notably Microsoft's, was removed and BASIC-PLUS's string functions became the only ways to perform these sorts of operations. Most BASICs to this day follow this convention. The language was later rewritten as a true ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Switch Statement
In computer programming languages, a switch statement is a type of selection control mechanism used to allow the value of a variable or expression to change the control flow of program execution via search and map. Switch statements function somewhat similarly to the if statement used in programming languages like C/C++, C#, Visual Basic .NET, Java and exists in most high-level imperative programming languages such as Pascal, Ada, C/C++, C#, Visual Basic .NET, Java, and in many other types of language, using such keywords as switch, case, select or inspect. Switch statements come in two main variants: a structured switch, as in Pascal, which takes exactly one branch, and an unstructured switch, as in C, which functions as a type of goto. The main reasons for using a switch include improving clarity, by reducing otherwise repetitive coding, and (if the heuristics permit) also offering the potential for faster execution through easier compiler optimization in many cases. His ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tiny BASIC
Tiny BASIC is a family of dialects of the BASIC programming language that can fit into 4 or fewer KBs of memory. Tiny BASIC was designed in response to the open letter published by Bill Gates complaining about users pirating Altair BASIC, which sold for $150. Tiny BASIC was intended to be a completely free version of BASIC that would run on the same early microcomputers. Tiny BASIC was released as a specification, not an implementation, published in the September 1975 issue of the People's Computer Company (PCC) newsletter. The article invited programmers to implement it on their machines and send the resulting assembler language implementation back for inclusion in a series of three planned newsletters. Li-Chen Wang, author of Palo Alto Tiny BASIC, coined the term "copyleft" to describe this concept. The community response was so overwhelming that the newsletter was relaunched as Dr. Dobb's Journal, the first regular periodical to focus on microcomputer software. Dr. Dobb's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dartmouth BASIC
Dartmouth BASIC is the original version of the BASIC programming language. It was designed by two professors at Dartmouth College, John G. Kemeny and Thomas E. Kurtz. With the underlying Dartmouth Time Sharing System (DTSS), it offered an interactive programming environment to all undergraduates as well as the larger university community. Several versions were produced at Dartmouth, implemented by undergraduate students and operating as a compile and go system. The first version ran on 1 May 1964, and it was opened to general users in June. Upgrades followed, culminating in the seventh and final release in 1979. Dartmouth also introduced a dramatically updated version known as Structured BASIC (or SBASIC) in 1975, which added various structured programming concepts. SBASIC formed the basis of the ANSI-standard Standard BASIC efforts in the early 1980s. Most dialects of BASIC trace their history to the Fourth Edition (which added e.g. string variables, which most BASIC users tak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subroutine
In computer programming, a function or subroutine is a sequence of program instructions that performs a specific task, packaged as a unit. This unit can then be used in programs wherever that particular task should be performed. Functions may be defined within programs, or separately in libraries that can be used by many programs. In different programming languages, a function may be called a routine, subprogram, subroutine, method, or procedure. Technically, these terms all have different definitions, and the nomenclature varies from language to language. The generic umbrella term ''callable unit'' is sometimes used. A function is often coded so that it can be started several times and from several places during one execution of the program, including from other functions, and then branch back (''return'') to the next instruction after the ''call'', once the function's task is done. The idea of a subroutine was initially conceived by John Mauchly during his work on ENIAC, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command Line
A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and providing information to them as to what actions they are to perform. In some cases the invocation is conditional based on conditions established by the user or previous executables. Such access was first provided by computer terminals starting in the mid-1960s. This provided an interactive environment not available with punched cards or other input methods. Today, many users rely upon graphical user interfaces and menu-driven interactions. However, some programming and maintenance tasks may not have a graphical user interface and use a command line. Alternatives to the command-line interface include text-based user interface menus (for example, IBM AIX SMIT), keyboard shortcuts, and various desktop metaphors centered on the pointer (usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DOPE (Dartmouth Oversimplified Programming Experiment)
DOPE, short for Dartmouth Oversimplified Programming Experiment, was a simple programming language designed by John Kemény in 1962 to offer students a transition from flow-charting to programming the LGP-30. Lessons learned from implementing DOPE were subsequently applied to the invention and development of BASIC. Description Each statement was designed to correspond to a flowchart operation and consisted of a numeric line number, an operation, and the required operands: 7 + A B C 10 SIN X Z The final variable specified the destination for the computation. The above program corresponds in functionality to the later BASIC program: DOPE might be the first programming language to require every statement to have a line number, predating JOSS and BASIC. The language was case insensitive. Variable names were a single letter A to Z, or a letter followed by a digit (A0 to Z9). As with Fortran, different letters represented different variable types. Variables starting with lette ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Punched Card
A punched card (also punch card or punched-card) is a piece of stiff paper that holds digital data represented by the presence or absence of holes in predefined positions. Punched cards were once common in data processing applications or to directly control automated machinery. Punched cards were widely used through much of the 20th century in the data processing industry, where specialized and increasingly complex unit record equipment, unit record machines, organized into semiautomatic data processing systems, used punched cards for data input, output, and storage. The IBM 12-row/80-column punched card format came to dominate the industry. Many early digital computers used punched cards as the primary medium for input of both computer programs and Data (computing), data. While punched cards are now obsolete as a storage medium, as of 2012, some voting machines still used punched cards to record votes. They also had a significant cultural impact. History The idea of contr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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