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It is also the only native bit, multicore-enabled application of its kind. The program features efficient batch delete and batch file management functions: users can streamline their workflow by automating file import, copy, move, export-for-web, backup to multiple drives and delete operations using functionality built directly in the program. Rules can be applied according to metadata, dates, file types and other criteria. The batch file processor let users begin with point-and-click ease and plain English file management rules while advanced users can write their own custom actions in ECMAcompatible JavaScript or VBScript to automate their workflows in virtually every imaginable ways!

Axel Rietschin Software Developments, author and publisher of FastPictureViewer Professional and the FastPictureViewer Codec Pack products, is a privately held "family business" established in Geneva, Switzerland , the country of precision watches, delicious chocolate and blazing fast image viewers.

Axel started serious programming and hobby photography as a youngster almost at the same time, getting his first C compiler in and a Nikon FA shortly thereafter. He learned the rudiments of photography from his long-time friend Philippe Ayral, renowned French visual artist and former photojournalist, helping Philippe get around his first Apple II then Mac K computers at the same time.

Axel first worked independently then for several companies ranging from small startups to huge multinationals, as software design engineer, lead developer, systems architect and CTO, before beginning formal studies of mathematics and starting the FastPictureViewer projects as a side job in early FastPictureViewer Professional has reached its 1st million downloads during February Save time: preview, cull and rate pictures faster than ever before!

Google fastest image viewer and see who comes on top: 3 million users and counting cannot be wrong! When you are ready to move on, FastPictureViewer displays the next image instantly : no wait , not even a fraction of a second, when your computer has enough spare muscles to load two or more images at once. We could go on and on with geek talk about DirectX and Direct2D hardware acceleration, speculative image loading, pixel shaders and so on, but all you need to know is there is no faster culling software, at any price.

FastPictureViewer Pro is the best companion to Adobe Lightroom and other digital asset management systems: use it to weed-out your pictures before importing them for development and editing. Click to enlarge! Consider the following example: say you are a wedding or sports photographer coming back from an assignment with raw images, taken with a contemporary DSLR MP range.

Your first task is to review those images and select the ones deserving to be further processed. The majority of the saving comes from not importing all images in Lightroom and wait, then delete or set aside the one you don't want.

Describes a computer architecture where all processors have direct access to common physical memory. In a programming sense, it describes a model where parallel tasks all have the same "picture" of memory and can directly address and access the same logical memory locations regardless of where the physical memory actually exists. Shared memory hardware architecture where multiple processors share a single address space and have equal access to all resources - memory, disk, etc.

In hardware, refers to network based memory access for physical memory that is not common. As a programming model, tasks can only logically "see" local machine memory and must use communications to access memory on other machines where other tasks are executing.

Parallel tasks typically need to exchange data. There are several ways this can be accomplished, such as through a shared memory bus or over a network. Synchronization usually involves waiting by at least one task, and can therefore cause a parallel application's wall clock execution time to increase. In parallel computing, granularity is a quantitative or qualitative measure of the ratio of computation to communication. Required execution time that is unique to parallel tasks, as opposed to that for doing useful work.

Parallel overhead can include factors such as:. Refers to the hardware that comprises a given parallel system - having many processing elements. The meaning of "many" keeps increasing, but currently, the largest parallel computers are comprised of processing elements numbering in the hundreds of thousands to millions. Solving many similar, but independent tasks simultaneously; little to no need for coordination between the tasks.

Factors that contribute to scalability include:. Machine memory was physically distributed across networked machines, but appeared to the user as a single shared memory global address space.

Generically, this approach is referred to as "virtual shared memory". However, the ability to send and receive messages using MPI, as is commonly done over a network of distributed memory machines, was implemented and commonly used.

In both cases, the programmer is responsible for determining the parallelism although compilers can sometimes help. As the next version of Windows NT after Windows , as well as the successor to Windows Me , Windows XP introduced many new features but it also removed some others.

Use of these features is apparent in Windows XP's user interface transparent desktop icon labels, drop shadows for icon labels on the desktop, shadows under menus, translucent blue selection rectangle in Windows Explorer , sliding task panes and taskbar buttons , and several of its applications such as Microsoft Paint , Windows Picture and Fax Viewer , Photo Printing Wizard , My Pictures Slideshow screensaver, and their presence in the basic graphics layer greatly simplifies implementations of vector-graphics systems such as Flash or SVG.

The total number of GDI handles per session is also raised in Windows XP from 16, to 65, configurable through the registry. Windows XP shipped with DirectX 8. Direct3D introduced programmability in the form of vertex and pixel shaders , enabling developers to write code without worrying about superfluous hardware state, and fog , bump mapping and texture mapping.

Windows XP can be upgraded to DirectX 9. Windows XP includes ClearType subpixel rendering , which makes onscreen fonts smoother and more readable on liquid crystal display LCD screens. There are other parameters such as contrast that can be set via a ClearType Tuner powertoy that Microsoft makes available as a free download from its Typography website. To help the user access a wider range of common destinations more easily from a single location, the Start menu was expanded to two columns; the left column focuses on the user's installed applications, while the right column provides access to the user's documents, and system links which were previously located on the desktop.

Links to the My Documents, My Pictures and other special folders are brought to the fore. The My Computer and My Network Places Network Neighborhood in Windows 95 and 98 icons were also moved off the Desktop and into the Start menu, making it easier to access these icons while a number of applications are open and so that the desktop remains clean. Moreover, these links can be configured to expand as a cascading menu. Frequently used programs are automatically displayed in the left column, newly installed programs are highlighted, and the user may opt to "pin" programs to the start menu so that they are always accessible without having to navigate through the Programs folders.

The default internet browser and default email program are pinned to the Start menu. The Start menu is fully customizable, links can be added or removed; the number of frequently used programs to display can be set. The All Programs menu expands like the classic Start menu to utilize the entire screen but can be set to scroll programs.

The user's name and user's account picture are also shown on the Start menu. The taskbar buttons for running applications and Quick Launch have also been updated for Fitt's law. Locking the taskbar not only prevents it from being accidentally resized or moved but elements such as Quick launch and other DeskBands are also locked from being accidentally moved.

The Taskbar grouping feature combines multiple buttons of the same application into a single button, which when clicked, pops up a menu listing all the grouped windows and their number. Advanced taskbar grouping options can be configured from the registry. A button allows the user to reveal all the icons. The Taskbar, if set to a thicker height also displays the day and date in the notification area.

There are significant changes made to Windows Explorer in Windows XP, both visually and functionally. Microsoft focused especially on making Windows Explorer more discoverable and task-based, as well as adding a number of features to reflect the growing use of a computer as a "digital hub". The task pane is displayed on the left side of the window instead of the traditional folder tree view when the navigation pane is turned off.

It presents the user with a list of common actions and destinations that are relevant to the current directory or file s selected. For instance, when in a directory containing mostly pictures, a set of "Picture tasks" is shown, offering the options to display these pictures as a slide show, to print them, or to go online to order prints. Conversely, a folder containing music files would offer options to play those files in a media player, or to go online to purchase music.

Every folder also has "File and Folder Tasks", offering options to create new folders, share a folder on the local network, publish files or folders to a web site using the Web Publishing Wizard , and other common tasks like copying, renaming, moving, and deleting files or folders.

File types that have identified themselves as being printable also have an option listed to print the file. Underneath "File and Folder Tasks" is "Other Places", which always lists the parent folder of the folder being viewed and includes additional links to other common locations such as "My Computer", "Control Panel", and "My Documents" or previously navigated locations.

These change depending on what folder the user was in. Underneath "Other Places" is a "Details" area which gives additional information when a file or folder is selected — typically the file type, file size and date modified, but depending on the file type, author, image dimensions, attributes, or other details.

If the file type has a Thumbnail image handler installed, its preview also appears in the "Details" task pane. For music files, it might show the artist, album title, and the length of the song. The same information is also shown horizontally on the status bar. The "Folders" button on the Windows Explorer toolbar toggles between the traditional navigation pane containing the tree view of folders, and the task pane.

Users can also close the navigation pane by clicking the Close button in its right corner as well as turn off the task pane from Folder Options.

The navigation pane has been enhanced in Windows XP to support "simple folder view" which when turned on hides the dotted lines that connect folders and subfolders and makes folders browsable with single click while still keeping double clicking on in the right pane.

Single clicking in simple folder view auto expands the folder and clicking another folder automatically expands that folder and collapses the previous one.

Windows XP introduced a large number of metadata properties [7] which are shown as columns in the "Details" view of Explorer, in the new Tiles view in Explorer, on the Summary tab in a file's properties, in a file's tooltip and on the Explorer status bar when a single file is selected.

Users also gain the ability to sort by any property which is turned on in "Details" view. Developers can write column handler shell extensions to further define their own properties by which files can be sorted. The column by which items are sorted is highlighted. Sorting files and folders can be in Ascending order or Descending order in all views, not just Details view. To reverse the order, the user simply can perform the sort by the same property again.

The sort order has also been made more intuitive compared to the one in Windows For file names containing numbers Windows Explorer now tries to sort based on numerical value rather than just comparing each number digit by digit for every character position in the file name.

The right pane of Windows Explorer has a "Show in Groups" feature which allows Explorer to separate its contents by headings based on any field which is used to sort the items. Items can thus be grouped by any detail which is turned on.

Microsoft introduced animated "Search Companions" in an attempt to make searching more engaging and friendly; the default character is a puppy named Rover, with three other characters Merlin the magician, Earl the surfer, and Courtney also available. These search companions powered by Microsoft Agent technology, bear a great deal of similarity to Microsoft Office 's Office Assistants , even incorporating "tricks" and sound effects.

If the user wishes, they can also turn off the animated character entirely. The search capability itself is fairly similar to Windows Me and Windows , with some important additions. Search can also be instructed to search only files that are categorically "Documents" or "Pictures, music and video" searching by perceived type ; this feature is noteworthy largely because of how Windows determines what types of files can be classified under these categories.

Using Tweak UI , the search user interface can be restored to the one used by Windows Windows XP improves image preview by offering a Filmstrip view which shows images in a single horizontal row and a large preview of the currently selected image above it.

Filmstrip view like any other view can be turned on per folder. This view will be available if the new "Common Tasks" folder view is selected, not with "Windows Classic" folder view. Aside from the Filmstrip view mode, there is a 'Thumbnails' view, which displays thumbnail -sized images in the folder and also displays images a subfolder may be containing 4 by default overlaid on a large folder icon.

A folder's thumbnail view can be customized from the Customize tab accessible from its Properties, where users can also change the folder's icon and specify a template type pictures, music, videos, documents for that folder and optionally all its subfolders. The size and quality of thumbnails in "Thumbnails" view can be adjusted using Tweak UI or the registry.

Windows XP optionally caches the thumbnails in a " Thumbs. Thumbnails can be forced to regenerate by right-clicking the image in Thumbnail or Filmstrip views and selecting "Refresh thumbnail". AutoPlay examines newly discovered removable media and devices and, based on content such as pictures, music or video files, launches an appropriate application to play or display the content. AutoPlay can be enhanced by AutoPlay-compatible software and hardware.

It can be configured by the user to associate favourite applications with AutoPlay events and actions. These actions are called AutoPlay Handlers and there are sets of Handlers associated with various types of content. New AutoPlay handlers can get added to the system when additional software is installed.

AutoPlay settings can be configured per-device in Windows XP from the device's properties. When a user inserts an optical disc into a drive or attaches a USB camera, Windows detects the arrival and starts a process of examining the device or searching the medium.

It is looking for properties of the device or content on the medium so that AutoPlay can present a set of meaningful options to the user.

When the user makes a particular choice, they also have the option to make that selection automatic the next time Windows sees that content or device. It supersedes part of the functions of Imaging for Windows in previous versions of Windows. The Windows Picture and Fax Viewer is integrated with Windows Explorer for functions like slideshow, email, printing etc. It supports full file management from within the viewer itself, that is, right clicking the image shows the same context menu as the one shown when an image is right clicked in Windows Explorer.

Images can be set as the desktop wallpaper from the context menu. It supports successive viewing of all images in current folder and looping through images, [17] that is, after viewing the last image in a directory, it again shows the first image and vice versa.

By default, images smaller than the user's display resolution are shown at their actual size. If an image is larger than the display resolution, it is scaled to fit the screen Best Fit. When this is done, scroll bars allow for viewing of all areas of the image.

The wizard shows a preview of what the printed page will look like with the currently specified options. Using Tweak UI , the time between images during a slideshow can be adjusted. GIF files are shown with full animation, even when zoomed.

Areas of the image can be selected and concealed. Windows Picture and Fax Viewer saves and remembers its window position and size and supports keyboard shortcuts for all of its operations. Raw image formats , which are the preferred formats in professional photography are not supported, however, Microsoft released a later update called RAW Image Thumbnailer and Viewer for Windows XP for viewing certain raw image files.

The Text Services Framework is designed to offer advanced language and word processing features to applications. It supports features such as multilingual support, keyboard drivers, handwriting recognition , speech recognition , as well as spell checking and other text and natural language processing functions.

It is also downloadable for older Windows operating systems. The language bar enables text services to add UI elements to the toolbar and enables these elements when an application has focus. From the Language Bar, users can select the input language, and control keyboard input, handwriting recognition and speech recognition. The language bar also provides a direct means to switch between installed languages, even when a non-TSF-enabled application has focus.

Although an upgrade of the Windows kernel, there are major scalability, stability and performance improvements, albeit transparent to the end user. Windows XP includes simultaneous multithreading hyperthreading support. Simultaneous multithreading is a processor's ability to process more than one data thread at a time. Windows XP supports a larger system virtual address space —— 1. The Windows XP Memory Manager is redesigned to consume less paged pool, allowing for more caching and greater availability of paged pool for any component that needs it.

The total size of memory-mapped files in Windows was limited because the memory manager allocated the Prototype Page Table entries PPTEs for the entire file, even if an application created mapped views to only parts of the file. A benefit of this, for example, is in case of making backups of large files on low memory systems. The paged pool limit of MB has been lifted from the Memory Manager in Windows XP, with unmapped views dynamically reusable by the memory manager depending on pool usage.

Memory pages in working sets are trimmed more efficiently for multiprocessor systems depending on how recently they were accessed.

The dispatcher lock contention has been reduced and the Page Frame Number PFN lock has been optimized for increased parallelism and granularity. Windows XP uses push locks on the event synchronization object if there is no contention as they support shared and exclusive acquisition. Push locks protect handle table entries in the Executive , and in the Object Manager to protect data structures and security descriptors and Memory Manager to protect AWE -related locks.

The kernel page write protection limit in Windows XP is enabled on systems up to MB of RAM beyond which large pages are enabled for increased address translation performance. Windows XP introduces the CreateMemoryResourceNotification function which can notify user mode processes of high or low memory availability so applications can allocate more memory or free up memory as necessary.

In Windows XP, the registry is reimplemented outside of the paged pool; the registry hives are memory mapped by the Cache Manager into the system cache, eliminating the registry size limit.

The registry size is now limited only by the available disk space. Flash memory blurs the distinction between ROM and RAM, as it retains its data when turned off but is also rewritable. It is typically much slower than conventional ROM and RAM however, so its use is restricted to applications where high speed is unnecessary. In more sophisticated computers there may be one or more RAM cache memories , which are slower than registers but faster than main memory.

Generally computers with this sort of cache are designed to move frequently needed data into the cache automatically, often without the need for any intervention on the programmer's part. Hard disk drives , floppy disk drives and optical disc drives serve as both input and output devices. A graphics processing unit might contain fifty or more tiny computers that perform the calculations necessary to display 3D graphics. A era flat screen display contains its own computer circuitry.

While a computer may be viewed as running one gigantic program stored in its main memory, in some systems it is necessary to give the appearance of running several programs simultaneously. This is achieved by multitasking i.

By remembering where it was executing prior to the interrupt, the computer can return to that task later. If several programs are running "at the same time". Since modern computers typically execute instructions several orders of magnitude faster than human perception, it may appear that many programs are running at the same time even though only one is ever executing in any given instant. This method of multitasking is sometimes termed "time-sharing" since each program is allocated a "slice" of time in turn.

Before the era of inexpensive computers, the principal use for multitasking was to allow many people to share the same computer. If a program is waiting for the user to click on the mouse or press a key on the keyboard, then it will not take a "time slice" until the event it is waiting for has occurred.

This frees up time for other programs to execute so that many programs may be run simultaneously without unacceptable speed loss.

Some computers are designed to distribute their work across several CPUs in a multiprocessing configuration, a technique once employed in only large and powerful machines such as supercomputers , mainframe computers and servers.

Multiprocessor and multi-core multiple CPUs on a single integrated circuit personal and laptop computers are now widely available, and are being increasingly used in lower-end markets as a result. Supercomputers in particular often have highly unique architectures that differ significantly from the basic stored-program architecture and from general-purpose computers.

Such designs tend to be useful for only specialized tasks due to the large scale of program organization required to successfully utilize most of the available resources at once. Supercomputers usually see usage in large-scale simulation , graphics rendering , and cryptography applications, as well as with other so-called " embarrassingly parallel " tasks. Software refers to parts of the computer which do not have a material form, such as programs, data, protocols, etc.

Software is that part of a computer system that consists of encoded information or computer instructions, in contrast to the physical hardware from which the system is built. Computer software includes computer programs , libraries and related non-executable data , such as online documentation or digital media. It is often divided into system software and application software Computer hardware and software require each other and neither can be realistically used on its own.

There are thousands of different programming languages—some intended for general purpose, others useful for only highly specialized applications.

The defining feature of modern computers which distinguishes them from all other machines is that they can be programmed. That is to say that some type of instructions the program can be given to the computer, and it will process them. Modern computers based on the von Neumann architecture often have machine code in the form of an imperative programming language. In practical terms, a computer program may be just a few instructions or extend to many millions of instructions, as do the programs for word processors and web browsers for example.

A typical modern computer can execute billions of instructions per second gigaflops and rarely makes a mistake over many years of operation. Large computer programs consisting of several million instructions may take teams of programmers years to write, and due to the complexity of the task almost certainly contain errors. This section applies to most common RAM machine —based computers. In most cases, computer instructions are simple: add one number to another, move some data from one location to another, send a message to some external device, etc.

These instructions are read from the computer's memory and are generally carried out executed in the order they were given. However, there are usually specialized instructions to tell the computer to jump ahead or backwards to some other place in the program and to carry on executing from there.

These are called "jump" instructions or branches. Furthermore, jump instructions may be made to happen conditionally so that different sequences of instructions may be used depending on the result of some previous calculation or some external event.

Many computers directly support subroutines by providing a type of jump that "remembers" the location it jumped from and another instruction to return to the instruction following that jump instruction. Program execution might be likened to reading a book.

While a person will normally read each word and line in sequence, they may at times jump back to an earlier place in the text or skip sections that are not of interest. Similarly, a computer may sometimes go back and repeat the instructions in some section of the program over and over again until some internal condition is met.

This is called the flow of control within the program and it is what allows the computer to perform tasks repeatedly without human intervention. Comparatively, a person using a pocket calculator can perform a basic arithmetic operation such as adding two numbers with just a few button presses. But to add together all of the numbers from 1 to 1, would take thousands of button presses and a lot of time, with a near certainty of making a mistake.

On the other hand, a computer may be programmed to do this with just a few simple instructions. The following example is written in the MIPS assembly language :. Once told to run this program, the computer will perform the repetitive addition task without further human intervention. It will almost never make a mistake and a modern PC can complete the task in a fraction of a second. In most computers, individual instructions are stored as machine code with each instruction being given a unique number its operation code or opcode for short.

The command to add two numbers together would have one opcode; the command to multiply them would have a different opcode, and so on. The simplest computers are able to perform any of a handful of different instructions; the more complex computers have several hundred to choose from, each with a unique numerical code.

Since the computer's memory is able to store numbers, it can also store the instruction codes. This leads to the important fact that entire programs which are just lists of these instructions can be represented as lists of numbers and can themselves be manipulated inside the computer in the same way as numeric data. The fundamental concept of storing programs in the computer's memory alongside the data they operate on is the crux of the von Neumann, or stored program, architecture.

This is called the Harvard architecture after the Harvard Mark I computer. Modern von Neumann computers display some traits of the Harvard architecture in their designs, such as in CPU caches. While it is possible to write computer programs as long lists of numbers machine language and while this technique was used with many early computers, [h] it is extremely tedious and potentially error-prone to do so in practice, especially for complicated programs. These mnemonics are collectively known as a computer's assembly language.

Converting programs written in assembly language into something the computer can actually understand machine language is usually done by a computer program called an assembler.

Programming languages provide various ways of specifying programs for computers to run. Unlike natural languages , programming languages are designed to permit no ambiguity and to be concise. They are purely written languages and are often difficult to read aloud.

They are generally either translated into machine code by a compiler or an assembler before being run, or translated directly at run time by an interpreter. Sometimes programs are executed by a hybrid method of the two techniques. Machine languages and the assembly languages that represent them collectively termed low-level programming languages are generally unique to the particular architecture of a computer's central processing unit CPU. Although considerably easier than in machine language, writing long programs in assembly language is often difficult and is also error prone.

Therefore, most practical programs are written in more abstract high-level programming languages that are able to express the needs of the programmer more conveniently and thereby help reduce programmer error.

High level languages are usually "compiled" into machine language or sometimes into assembly language and then into machine language using another computer program called a compiler.

It is therefore often possible to use different compilers to translate the same high level language program into the machine language of many different types of computer. This is part of the means by which software like video games may be made available for different computer architectures such as personal computers and various video game consoles. Program design of small programs is relatively simple and involves the analysis of the problem, collection of inputs, using the programming constructs within languages, devising or using established procedures and algorithms, providing data for output devices and solutions to the problem as applicable.

As problems become larger and more complex, features such as subprograms, modules, formal documentation, and new paradigms such as object-oriented programming are encountered. Large programs involving thousands of line of code and more require formal software methodologies.

The task of developing large software systems presents a significant intellectual challenge. Producing software with an acceptably high reliability within a predictable schedule and budget has historically been difficult; the academic and professional discipline of software engineering concentrates specifically on this challenge.

Errors in computer programs are called " bugs ". They may be benign and not affect the usefulness of the program, or have only subtle effects. But in some cases, they may cause the program or the entire system to " hang ", becoming unresponsive to input such as mouse clicks or keystrokes, to completely fail, or to crash. Bugs are usually not the fault of the computer. Since computers merely execute the instructions they are given, bugs are nearly always the result of programmer error or an oversight made in the program's design.

Computers have been used to coordinate information between multiple locations since the s. The U. In time, the network spread beyond academic and military institutions and became known as the Internet. The emergence of networking involved a redefinition of the nature and boundaries of the computer. Computer operating systems and applications were modified to include the ability to define and access the resources of other computers on the network, such as peripheral devices, stored information, and the like, as extensions of the resources of an individual computer.

Initially these facilities were available primarily to people working in high-tech environments, but in the s the spread of applications like e-mail and the World Wide Web , combined with the development of cheap, fast networking technologies like Ethernet and ADSL saw computer networking become almost ubiquitous. In fact, the number of computers that are networked is growing phenomenally. A very large proportion of personal computers regularly connect to the Internet to communicate and receive information.

A computer does not need to be electronic , nor even have a processor , nor RAM , nor even a hard disk. While popular usage of the word "computer" is synonymous with a personal electronic computer, [l] the modern definition of a computer is literally: " A device that computes , especially a programmable [usually] electronic machine that performs high-speed mathematical or logical operations or that assembles, stores, correlates, or otherwise processes information.

There is active research to make computers out of many promising new types of technology, such as optical computers , DNA computers , neural computers , and quantum computers. Most computers are universal, and are able to calculate any computable function , and are limited only by their memory capacity and operating speed. However different designs of computers can give very different performance for particular problems; for example quantum computers can potentially break some modern encryption algorithms by quantum factoring very quickly.

There are many types of computer architectures :. Of all these abstract machines , a quantum computer holds the most promise for revolutionizing computing. The ability to store and execute lists of instructions called programs makes computers extremely versatile, distinguishing them from calculators.

The Church—Turing thesis is a mathematical statement of this versatility: any computer with a minimum capability being Turing-complete is, in principle, capable of performing the same tasks that any other computer can perform. Therefore, any type of computer netbook , supercomputer , cellular automaton , etc.

A computer will solve problems in exactly the way it is programmed to, without regard to efficiency, alternative solutions, possible shortcuts, or possible errors in the code. Computer programs that learn and adapt are part of the emerging field of artificial intelligence and machine learning. Artificial intelligence based products generally fall into two major categories: rule-based systems and pattern recognition systems.

Rule-based systems attempt to represent the rules used by human experts and tend to be expensive to develop. Pattern-based systems use data about a problem to generate conclusions. Examples of pattern-based systems include voice recognition , font recognition, translation and the emerging field of on-line marketing. As the use of computers has spread throughout society, there are an increasing number of careers involving computers.

The need for computers to work well together and to be able to exchange information has spawned the need for many standards organizations, clubs and societies of both a formal and informal nature. From Wikipedia, the free encyclopedia. Automatic general-purpose device for performing arithmetic or logical operations.

For other uses, see Computer disambiguation. Computers and computing devices from different eras. Main articles: History of computing and History of computing hardware. For a chronological guide, see Timeline of computing. Main article: Analog computer. Main article: Stored-program computer. Main articles: Transistor and History of the transistor. Main articles: Integrated circuit and Invention of the integrated circuit. Further information: Planar process and Microprocessor.

See also: Classes of computers. Main articles: Computer hardware , Personal computer hardware , Central processing unit , and Microprocessor. Main article: History of computing hardware. Main articles: CPU design and Control unit. Main articles: Central processing unit and Microprocessor. Main article: Arithmetic logic unit. Main articles: Computer memory and Computer data storage. Main article: Computer multitasking.

Main article: Multiprocessing. Main article: Software. Main articles: Computer program and Computer programming.

Main article: Programming language. Main article: Low-level programming language. Main article: High-level programming language. This section does not cite any sources. Please help improve this section by adding citations to reliable sources.

Unsourced material may be challenged and removed. July Learn how and when to remove this template message. Main article: Software bug. Main articles: Computer networking and Internet. Main article: Human computer.

See also: Harvard Computers. Glossary of computers Computability theory Computer security Glossary of computer hardware terms History of computer science List of computer term etymologies List of fictional computers List of pioneers in computer science Pulse computation TOP list of most powerful computers Unconventional computing.

The containers thus served as something of a bill of lading or an accounts book. In order to avoid breaking open the containers, first, clay impressions of the tokens were placed on the outside of the containers, for the count; the shapes of the impressions were abstracted into stylized marks; finally, the abstract marks were systematically used as numerals; these numerals were finally formalized as numbers.

Eventually the marks on the outside of the containers were all that were needed to convey the count, and the clay containers evolved into clay tablets with marks for the count. Schmandt-Besserat estimates it took years. All of the architectures listed in this table, except for Alpha, existed in bit forms before their bit incarnations were introduced. Although the control unit is solely responsible for instruction interpretation in most modern computers, this is not always the case.

Some computers have instructions that are partially interpreted by the control unit with further interpretation performed by another device. For example, EDVAC , one of the earliest stored-program computers, used a central control unit that interpreted only four instructions. All of the arithmetic-related instructions were passed on to its arithmetic unit and further decoded there.

These so-called computer clusters can often provide supercomputer performance at a much lower cost than customized designs. While custom architectures are still used for most of the most powerful supercomputers, there has been a proliferation of cluster computers in recent years.

However, this method was usually used only as part of the booting process. Most modern computers boot entirely automatically by reading a boot program from some non-volatile memory.