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NORD-PL
Nord Programming Language (NPL), is a procedural programming language by the Norwegian minicomputer manufacturer Norsk Data. It shipped as a standard component of the operating system Sintran III. The language was also used to implement Sintran III: the core and file system of which are written in NPL, as was the NPL compiler, and some core applications early on, until the release of high-level programming language named PLANC. Then, the linker and other software were rewritten in PLANC. The NPL compiler was also special in that it did not emit object code as most compilers do. Instead it emitted an intermediate representation, in the form of assembly language code, which then had to be assembled using the Norsk Data Assembler MAC was a Macro assembler for computers of the NORD-1, NORD-10, and ND-100 lines from Norsk Data. Limitations The assembler had several snags which today would be considered exotic or strange. Identifier length Like many assemblers MAC placed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Procedural Programming
Procedural programming is a programming paradigm, derived from imperative programming, based on the concept of the ''procedure call''. Procedures (a type of routine or subroutine) simply contain a series of computational steps to be carried out. Any given procedure might be called at any point during a program's execution, including by other procedures or itself. The first major procedural programming languages appeared circa 1957–1964, including Fortran, ALGOL, COBOL, PL/I and BASIC. Pascal and C were published circa 1970–1972. Computer processors provide hardware support for procedural programming through a stack register and instructions for calling procedures and returning from them. Hardware support for other types of programming is possible, but no attempt was commercially successful (for example Lisp machines or Java processors). Procedures and modularity Modularity is generally desirable, especially in large, complicated programs. Inputs are usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-level Programming Language
In computer science, a high-level programming language is a programming language with strong Abstraction (computer science), abstraction from the details of the computer. In contrast to low-level programming languages, it may use natural language ''elements'', be easier to use, or may automate (or even hide entirely) significant areas of computing systems (e.g. memory management), making the process of developing a program simpler and more understandable than when using a lower-level language. The amount of abstraction provided defines how "high-level" a programming language is. In the 1960s, a high-level programming language using a compiler was commonly called an ''autocode''. Examples of autocodes are COBOL and Fortran. The first high-level programming language designed for computers was Plankalkül, created by Konrad Zuse. However, it was not implemented in his time, and his original contributions were largely isolated from other developments due to World War II, aside from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entry Point
In computer programming, an entry point is the place in a program where the execution of a program begins, and where the program has access to command line arguments. To start a program's execution, the loader or operating system passes control to its entry point. (During booting, the operating system itself is the program). This marks the transition from load time (and dynamic link time, if present) to run time. For some operating systems and programming languages, the entry point is in a runtime library, a set of support functions for the language. The library code initializes the program and then passes control to the program proper. In other cases, the program may initialize the runtime library itself. In simple systems, execution begins at the first statement, which is common in interpreted languages, simple executable formats, and boot loaders. In other cases, the entry point is at some other known memory address which can be an absolute address or relative address ( ... [...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] |
Variable (computer Science)
In computer programming, a variable is an abstract storage location paired with an associated symbol, symbolic name, which contains some known or unknown quantity of information referred to as a ''value (computer science), value''; or in simpler terms, a variable is a named container for a particular set of bits or :simple:Data_type, type of data (like Integer (computer science), integer, Floating-point arithmetic, float, String (computer science), string etc...). A variable can eventually be associated with or identified by a memory address. The variable name is the usual way to Reference (computer science), reference the stored value, in addition to referring to the variable itself, depending on the context. This separation of name and content allows the name to be used independently of the exact information it represents. The identifier in computer source code can be Name binding, bound to a Value (computer science), value during Run time (program lifecycle phase), run time, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norsk Data Assembler
MAC was a Macro assembler for computers of the NORD-1, NORD-10, and ND-100 lines from Norsk Data. Limitations The assembler had several snags which today would be considered exotic or strange. Identifier length Like many assemblers MAC placed a limit on the length of variable names, however, rather than simply disallowing names greater than the maximum length it only kept the last five letters of an identifier, ignoring the first part of the name. The reason for keeping the last 5 was so that variables such as MY_ARRAY1 and MY_ARRAY2 would be distinguishable. The result was that the internal storage of some names was very strange and some times hard to understand as the names would be identical to names such as RRAY1 and RRAY2 respectively. This behavior caused some programmers to adopt the practice of writing only the last five letters of a name in their program code as the assembler would ignore the rest anyway. Because of the difficulty faced by a human reader in understand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assembly 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] |
Intermediate Representation
An intermediate representation (IR) is the data structure or code used internally by a compiler or virtual machine to represent source code. An IR is designed to be conducive to further processing, such as optimization and translation. A "good" IR must be ''accurate'' – capable of representing the source code without loss of information – and ''independent'' of any particular source or target language. An IR may take one of several forms: an in-memory data structure, or a special tuple- or stack-based code readable by the program. In the latter case it is also called an ''intermediate language''. A canonical example is found in most modern compilers. For example, the CPython interpreter transforms the linear human-readable text representing a program into an intermediate graph structure that allows flow analysis and re-arrangement before execution. Use of an intermediate representation such as this allows compiler systems like the GNU Compiler Collection and LLVM to be use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object Code
In computing, object code or object module is the product of a compiler. In a general sense object code is a sequence of statements or instructions in a computer language, usually a machine code language (i.e., binary) or an intermediate language such as register transfer language (RTL). The term indicates that the code is the goal or result of the compiling process, with some early sources referring to source code as a "subject program". Details Object files can in turn be linked to form an executable file or library file. In order to be used, object code must either be placed in an executable file, a library file, or an object file. Object code is a portion of machine code that has not yet been linked into a complete program. It is the machine code for one particular library or module that will make up the completed product. It may also contain placeholders or offsets, not found in the machine code of a completed program, that the linker will use to connect everything toget ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linker (computing)
In computing, a linker or link editor is a computer system program that takes one or more object files (generated by a compiler or an assembler) and combines them into a single executable file, library file, or another "object" file. A simpler version that writes its output directly to memory is called the ''loader'', though loading is typically considered a separate process. Overview Computer programs typically are composed of several parts or modules; these parts/modules do not need to be contained within a single object file, and in such cases refer to each other by means of symbols as addresses into other modules, which are mapped into memory addresses when linked for execution. While the process of linking is meant to ultimately combine these independent parts, there are many good reasons to develop those separately at the source-level. Among these reasons are the ease of organizing several smaller pieces over a monolithic whole and the ability to better define the pur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PLANC
PLANC (Programming LAnguage for Nd Computers, pronounced as ''plank'') is a high-level programming language. Compilers were developed by Norsk Data for several architectures, including the Motorola 68000, 88000, Intel x86, and the Norsk Data Nord-10 minicomputers and ND-500 superminicomputer. The language was designed to be cross-platform software. It was mainly used internally at Norsk Data for writing high level systems software such as the upper parts of operating systems and compilers. Basic structure PLANC programs are structured into modules and routines. A very simple example of a PLANC program is as follows: MODULE mod INTEGER ARRAY : stack (0:100) PROGRAM : mprog INTEGER : i, j,k, m INISTACK stack 1 =: i 2 =: j i+j =: k =: m ENDROUTINE ENDMODULE A difference from popular programming languages is that the assignment operator evaluates from left to right: First it computes the value, and then stores it. Compile-time in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compiler
In computing, a compiler is a computer program that translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primarily used for programs that translate source code from a high-level programming language to a low-level programming language (e.g. assembly language, object code, or machine code) to create an executable program. Compilers: Principles, Techniques, and Tools by Alfred V. Aho, Ravi Sethi, Jeffrey D. Ullman - Second Edition, 2007 There are many different types of compilers which produce output in different useful forms. A ''cross-compiler'' produces code for a different CPU or operating system than the one on which the cross-compiler itself runs. A ''bootstrap compiler'' is often a temporary compiler, used for compiling a more permanent or better optimised compiler for a language. Related software include, a program that translates from a low-level language to a h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
