Programs and Events at Jefferson Lab. Jefferson Lab's Education Programs.
Computer program - Wikipedia. A computer program is a collection of instructions. A computer requires programs to function, and typically executes the program's instructions in a central processing unit. From the program in its human- readable form of source code, a compiler can derive machine code. Alternatively, a computer program may be executed with the aid of an interpreter. A part of a computer program that performs a well- defined task is known as an algorithm. A collection of computer programs, libraries and related data are referred to as software. Programs & Events. Art After Hours; Film; Tours; Open Spaces. The Museum provides a wide variety of programs designed to reach audiences from. The goal is to make connections between the art on view to the time period. Computer programs may be categorized along functional lines, such as application software or system software. History. In 1. 80. Joseph- Marie Jacquard devised a loom that would weave a pattern by following a series of perforated cards. Patterns, including flowers and leaves, could be weaved and repeated by arranging the cards. In the textile industry, yarn was brought from the store to be milled. The device would have had a . It was programmed using two sets of perforated cards. The memoir covered the Analytical Engine. The translation contained Note G which completely detailed a method for calculating Bernoulli numbers using the Analytical Engine. This note is recognized by some historians as the world's first written computer program. The machine can move the tape back and forth, changing its contents as it performs an algorithm. The machine starts in the initial state, goes through a sequence of steps, and halts when it encounters the halt state. The Z3 contained 2,4. The circuits provided a binary, floating- point, nine- instruction computer. Programming the Z3 was through a specially designed keyboard and punched tape. The Electronic Numerical Integrator And Computer (Fall 1. Turing complete, general- purpose computer that used 1. At its core, it was a series of Pascalines wired together. Programming the ENIAC took up to two months. Function tables were connected to function panels using heavy black cables. Each function table had 7. Programming the ENIAC also involved setting some of the 3,0. Debugging a program took a week. Different sets of accumulators could simultaneously work on different algorithms. It used punched card machines for input and output, and it was controlled with a clock signal. It ran for eight years, calculating hydrogen bomb parameters, predicting weather patterns, and producing firing tables to aim artillery guns. The Manchester Small- Scale Experimental Machine (June 1. Only three bits of memory were available to store each instruction, so it was limited to eight instructions. Later computers. The computer program was written on paper for reference. An instruction was represented by a configuration of on/off settings. After setting the configuration, an execute button was pressed. This process was then repeated. Computer programs also were manually input via paper tape or punched cards. After the medium was loaded, the starting address was set via switches and the execute button pressed. The hardware featured circuits to ease the compile phase. The Model 3. 0 was the smallest and least expensive. Customers could upgrade and retain the same application software. With operating system support, multiple programs could be in memory at once. When one was waiting for input/output, another could compute. Each model also could emulate other computers. Customers could upgrade to the System/3. IBM 7. 09. 4 or IBM 1. Editing source code involves testing, analyzing, refining, and sometimes coordinating with other programmers on a jointly developed program. A person who practices this skill is referred to as a computer programmer, software developer, and sometimes coder. The sometimes lengthy process of computer programming is usually referred to as software development. The term software engineering is becoming popular as the process is seen as an engineering discipline. Programming languages. Two of the main paradigms are imperative and declarative. Imperative languages. Declarative programs omit the control flow and are considered sets of instructions. Two broad categories of declarative languages are functional languages and logical languages. The principle behind functional languages (like Haskell) is to not allow side effects, which makes it easier to reason about programs like mathematical functions. Then each subgoal is defined by further providing a list of its subgoals, etc. If a path of subgoals fails to find a solution, then that subgoal is backtracked and another path is systematically attempted. Compilation and interpretation. Source code may be converted into an executable image by a compiler or executed immediately with the aid of an interpreter. Compilers are used to translate source code from a programming language into either object code or machine code. Compiled computer programs are commonly referred to as executables, binary images, or simply as binaries . The interpreter decodes each statement and performs its behavior. One advantage of interpreters is that they have the ability to generate an interactive session. The programmer is presented with a prompt, and individual lines of code are typed in and performed immediately. The main disadvantage of interpreters is computer programs run slower than when compiled. Interpreting code is slower because the interpreter must decode each statement and then perform it. However, software development may be faster using an interpreter because testing is immediate when the compiling step is omitted. Another disadvantage of interpreters is an interpreter must be present on the executing computer. By contrast, compiled computer programs need no compiler present during execution. Just in time compilers pre- compile computer programs ahead of time and interpret them later. For example, Java computer programs are pre- compiled into a file containing bytecode. Bytecode is then executed by an interpreter called a virtual machine. Either compiled or interpreted programs might be executed in a batch process without human interaction. Batch programming languages are called scripting languages. One common scripting language is Unix shell, and its executing environment is called the command- line interface. No properties of a programming language require it to be exclusively compiled or exclusively interpreted. The categorization usually reflects the most popular method of language execution. For example, BASIC is thought of as an interpreted language and C a compiled language, despite the existence of BASIC compilers and C interpreters. Storage and execution. Upon such a request, the program is loaded into random- access memory, by a computer program called an operating system, where it can be accessed directly by the central processor. The central processor then executes (. A program in execution is called a process. Operating systems may run multiple programs through process scheduling . Multithreading processors are optimized to execute multiple threads efficiently. Self- modifying programs. However, in some cases, this distinction is blurred when a computer program modifies itself. The modified computer program is subsequently executed as part of the same program. Self- modifying code is possible for programs written in machine code, assembly language, Lisp, C, COBOL, PL/1, and Prolog. Functional categories. The main functional categories are application software and system software. System software includes the operating system which couples computer hardware with application software. Application software designed for end users have a user interface. Application software not designed for the end user includes middleware, which couples one application with another. Application software also includes utility programs. The distinction between system software and application software is under debate. Application software. It is a clipping of the word . They have been designed for many platforms, but the word was first used for smaller mobile apps. Desktop apps are traditional computer programs that run on desktop computers. Mobile apps run on mobile devices. Web apps run inside a web browser. Both mobile and desktop apps may be downloaded from the developers' website or purchased from app stores such as Windows Store, Apple App Store, Mac App Store, Google Play or Intel App. Up. An application suite consists of multiple applications bundled together. Examples include Microsoft Office, Libre. Office and i. Work. They bundle a word processor, spreadsheet, and other applications. Enterprise applications bundle accounting, personnel, customer, and vendor applications. Examples include enterprise resource planning, customer relationship management, and supply chain management software. Enterprise infrastructure software supports the enterprise's software systems. Examples include databases, email servers, and network servers. Information worker software are designed for workers at the departmental level. Examples include time management, resource management, analytical, collaborative and documentation tools. Word processors, spreadsheets, email and blog clients, personal information system, and individual media editors may aid in multiple information worker tasks. Media development software generates print and electronic media for others to consume, most often in a commercial or educational setting. These produce graphics, publications, animations, and videos. Product engineering software is used to help develop large machines and other application software. Examples includes computer- aided design (CAD), computer- aided engineering (CAE), and integrated development environments. Entertainment Software can refer to video games, movie recorders and players, and music recorders and players. Utility programs. If less fortunate, a memory printout was made for further study. The boot process is to identify and initialize all aspects of the system, from processor registers to device controllers to memory contents.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
December 2016
Categories |