Sunday 30 December 2012

GOOGLE SEARCH ENGINE 

SEARCHING IS FACILIATED BY SAIF UR REHMAN
PLEASE ENJOY AND USE IT

Wednesday 26 December 2012

win 98

Windows98.pngWindows 98 logo.svg
indows 98 includes Internet Explorer 4.01. Besides Internet Explorer, many other Internet companion applications are included such as Outlook Express, Windows Address Book, FrontPage Express, Microsoft Chat, Personal Web Server and a Web Publishing Wizard, NetMeeting and NetShow Player (in the original release of Windows 98) which was replaced by Windows Media Player 6.2 in Windows 98 Second Edition.
The Windows 98 shell includes all of the enhancements from Windows Desktop Update, an Internet Explorer 4 component, such as the Quick Launch toolbar, deskbands, Active DesktopChannels, ability to minimize foreground windows by clicking their button on the taskbar, single click launching, Back and Forward navigation buttons, favorites, and address bar in Windows Explorer, image thumbnails, folder infotips and web view in folders, and folder customization through HTML-based templates. Dialog boxes now show up in the Alt-Tab sequence.
Windows 98 also integrates shell enhancements, themes and other features from Microsoft Plus! for Windows 95 such as DriveSpace3, Compression Agent, Dial-Up Networking Server, Dial-Up Scripting Tool and Task Scheduler3D Pinball is included on the CD-ROM but not installed by default. Windows 98 had its own separately purchasable Plus! pack called Plus! 98.
Title bars of windows and dialog boxes support two-color gradients. Windows 98 menus and tooltips support slide animation. Windows Explorer in Windows 98, like Windows 95, converts all uppercase filenames to Sentence case for readability purposes,[5] however, it also provides an option Allow all uppercase names to display them in their original case. Windows Explorer includes support for compressed CAB files. The Quick Res and Telephony Location Manager Windows 95 PowerToys are integrated.

Thursday 20 December 2012

@SAIF UR REHMAN KHALID
MSC COMPUTER SCIENCE

multi-core processor is a single computing component with two or more independent actualcentral processing units (called "cores"), which are the units that read and execute program instructions.[1] The instructions are ordinary CPU instructions such as add, move data, and branch, but the multiple cores can run multiple instructions at the same time, increasing overall speed for programs amenable to parallel computing.[2] Manufacturers typically integrate the cores onto a single integrated circuit die (known as a chip multiprocessor or CMP), or onto multiple dies in a single chip package.
Processors were originally developed with only one core. A dual-core processor has two cores (e.g. AMD Phenom II X2, Intel Core Duo), a quad-core processor contains four cores (e.g. AMD Phenom II X4, Intel's quad-core processors, see i3i5, and i7 at Intel Core), a hexa-core processor contains six cores (e.g. AMD Phenom II X6, Intel Core i7 Extreme Edition 980X), anocta-core processor contains eight cores (e.g. Intel Xeon E7-2820, AMD FX-8150). A multi-core processor implements multiprocessing in a single physical package. Designers may couple cores in a multi-core device tightly or loosely. For example, cores may or may not share caches, and they may implement message passing or shared memory inter-core communication methods. Common network topologies to interconnect cores include bus, ring, two-dimensional mesh, andcrossbarHomogeneous multi-core systems include only identical cores, heterogeneous multi-core systems have cores that are not identical. Just as with single-processor systems, cores in multi-core systems may implement architectures such as superscalarVLIWvector processingSIMD, ormultithreading.
Multi-core processors are widely used across many application domains including general-purpose,embeddednetworkdigital signal processing (DSP), and graphics.
The improvement in performance gained by the use of a multi-core processor depends very much on the software algorithms used and their implementation. In particular, possible gains are limited by the fraction of the software that can be run in parallel simultaneously on multiple cores; this effect is described by Amdahl's law. In the best case, so-called embarrassingly parallel problems may realize speedup factors near the number of cores, or even more if the problem is split up enough to fit within each core's cache(s), avoiding use of much slower main system memory. Most applications, however, are not accelerated so much unless programmers invest a prohibitive amount of effort in re-factoring the whole problem.[3] The parallelization of software is a significant ongoing topic of research.

Monday 17 December 2012

SAIF UR REHMAN KHALID

INTERNET


The Internet (or internet) is a global system of interconnected computer networks that use the standard Internet protocol suite (often called TCP/IP, although not all applications use TCP) to serve billions of users worldwide. It is a network of networks that consists of millions of private, public, academic, business, and government networks, of local to global scope, that are linked by a broad array of electronic, wireless and optical networking technologies. The Internet carries an extensive range of information resources and services, such as the inter-linked hypertext documents of theWorld Wide Web (WWW) and the infrastructure to support email.
Most traditional communications media including telephone, music, film, and television are being reshaped or redefined by the Internet, giving birth to new services such as Voice over Internet Protocol (VoIP) and Internet Protocol Television (IPTV). Newspaper, book and other print publishing are adapting to Web site technology, or are reshaped into blogging and web feeds. The Internet has enabled and accelerated new forms of human interactions through instant messaging, Internet forums, and social networkingOnline shopping has boomed both for major retail outlets and smallartisans and traders. Business-to-business and financial services on the Internet affect supply chains across entire industries.
The origins of the Internet reach back to research of the 1960s, commissioned by the United States government to build robust, fault-tolerant, and distributed computer networks. The funding of a new U.S. backbone by the National Science Foundation in the 1980s, as well as private funding for other commercial backbones, led to worldwide participation in the development of new networking technologies, and the merger of many networks. The commercialization of what was by the 1990s an international network resulted in its popularization and incorporation into virtually every aspect of modern human life. As of June 2012, more than 2.4 billion people—nearly a third of the world's human population—have used the services of the Internet.[1]
The Internet has no centralized governance in either technological implementation or policies for access and usage; each constituent network sets its own standards. Only the overreaching definitions of the two principal name spaces in the Internet, the Internet Protocol address space and the Domain Name System, are directed by a maintainer organization, the Internet Corporation for Assigned Names and Numbers (ICANN). The technical underpinning and standardization of the core protocols (IPv4 and IPv6) is an activity of the Internet Engineering Task Force (IETF), a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise.

Saturday 15 December 2012

computer cables

SAIF UR REHMAN KHALID 

COMPUTER CABLES

File:Component-cables.jpg


SAIF UR REHMAN KHALID 



Thursday 13 December 2012

SAIF UR REHMAN KHALID
KEYBOARD
In computing, a keyboard is a typewriter-style device, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches. Following the decline ofpunch cards and paper tape, interaction via teleprinter-style keyboards became the maininput device for computers.
A keyboard typically has characters engraved or printed on the keys and each press of a key typically corresponds to a single written symbol. However, to produce some symbols requires pressing and holding several keys simultaneously or in sequence. While most keyboard keys produce lettersnumbers or signs (characters), other keys or simultaneous key presses can produce actions or computer commands.
Despite the development of alternative input devices, such as the mousetouchscreenpen devicescharacter recognition and voice recognition, the keyboard remains the most commonly used and most versatile device used for direct (human) input into computers.
In normal usage, the keyboard is used to type text and numbers into a word processortext editor or other programs. In a modern computer, the interpretation of key presses is generally left to the software. A computer keyboard distinguishes each physical key from every other and reports all key presses to the controlling software. Keyboards are also used for computer gaming, either with regular keyboards or by using keyboards with special gaming features, which can expedite frequently used keystroke combinations. A keyboard is also used to give commands to the operating system of a computer, such as WindowsControl-Alt-Delete combination, which brings up a task window or shuts down the machine. Keyboards are the only way to enter commands on a command-line interface.
File:QWERTY keyboard.jpg

Wednesday 12 December 2012

printer
by
saif ur Rehman


In computing, a printer is a peripheral which produces a representation of an electronic document on physical media such as paper or transparency film. Many printers are local peripherals connected directly to a nearby personal computer. Network printers have built-innetwork interfaces can serve any user on the network. Individual printers are often designed to support both local and network connected users at the same time. Some printers can print documents stored on memory cards or from digital cameras and scanners.Multifunction printers (MFPs) include a scanner and can copy paper documents or send afax; these are also called multi-function devices (MFD), or all-in-one (AIO) printers. Most MFPs include printing, scanning, and copying among their many features.
Consumer and some commercial printers are designed for low-volume, short-turnaround print jobs; requiring virtually no setup time to achieve a hard copy of a given document. However, printers are generally slow devices (30 pages per minute is considered fast, and many inexpensive consumer printers are far slower than that), and the cost per page is actually relatively high. However, this is offset by the on-demand convenience and project management costs being more controllable compared to an out-sourced solution. Theprinting press remains the machine of choice for high-volume, professional publishing. However, as printers have improved in quality and performance, many jobs which used to be done by professional print shops are now done by users on local printers; see desktop publishing. Local printers are also increasingly taking over the process of photofinishing as digital photo printers become commonplace.
The world's first computer printer was a 19th century mechanically driven apparatus invented by Charles Babbage for his difference engine.[1]

Sunday 9 December 2012



SAIF UR REHMAN 





The abacus (plural abaci or abacuses), also called a counting frame, is a calculating tool used primarily in parts of Asia for performing arithmetic processes. Today, abaci are often constructed as a bamboo frame with beads sliding on wires, but originally they were beans or stones moved in grooves in sand or on tablets of wood, stone, or metal. The abacus was in use centuries before the adoption of the written modern numeral system and is still widely used by merchants, traders and clerks in AsiaAfrica, and elsewhere. The user of an abacus is called an abacist.[2]
File:Gregor Reisch, Margarita Philosophica, 1508 (1230x1615).pnghe use of the word abacus dates before 1387 AD, when a Middle English work borrowed the word from Latin to describe a sandboard abacus. The Latin word came from Greek ἄβαξ abax "board strewn with sand or dust used for drawing geometric figures or calculating" (the exact shape of the Latin perhaps reflects the genitive form of the Greek word, ἄβακoς abakos). Greek ἄβαξ itself is probably a borrowing of a Northwest Semitic, perhaps Phoenician, word akin to Hebrew ʾābāq (אבק), "dust" (since dust strewn on wooden boards to draw figures in).[3] The preferred plural of abacus is a subject of disagreement, with both abacuses[4] and abaci[5] in use.

Saturday 8 December 2012


File:Windows 7.pngWindows 7 is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops, netbookstablet PCs, and media center PCs;[5] Windows 7 was released to manufacturing on July 22, 2009,[6] and reached general retail availability worldwide on October 22, 2009,[7] less than three years after the release of its predecessor, Windows Vista. Windows 7's server counterpart, Windows Server 2008 R2, was released at the same time. Windows 7 is succeeded by Windows 8, released on 26 October 2012.
Unlike Windows Vista, which introduced a large number of new features, Windows 7 was intended to be a more focused, incremental upgrade to the Windows line, with the goal of being compatible with applications and hardware with which Windows Vista was already compatible.[8] Presentations given by Microsoft in 2008 focused on multi-touch support, a redesigned Windows shellwith a new taskbar, referred to as the Superbar, a home networking system called HomeGroup,[9] and performance improvements. Some standard applications that have been included with prior releases of Microsoft Windows, including Windows CalendarWindows MailWindows Movie Maker, andWindows Photo Gallery, are not included in Windows 7;[10][11] most are instead offered separately at no charge as part of the Windows Essentials suite.

New and changed features

Windows 7 includes a number of new features, such as advances in touch and handwriting recognition, support for virtual hard disks, improved performance on multi-coreprocessors,[13][14][15][16] improved boot performance, DirectAccess, and kernelimprovements. Windows 7 adds support for systems using multiple heterogeneous graphics cards from different vendors (Heterogeneous Multi-adapter), a new version of Windows Media Center,[17] a Gadget for Windows Media Center, improved media features, the XPSEssentials Pack and Windows PowerShell being included, and a redesigned Calculator with multiline capabilities including Programmer and Statistics modes along with unit conversion for length, weight, temperature, and several others. Many new items have been added to theControl Panel, including ClearType Text Tuner, Display Color Calibration Wizard, Gadgets, Recovery, Troubleshooting, Workspaces Center, Location and Other Sensors, Credential Manager, Biometric Devices, System Icons, and Display.[18] Windows Security Center has been renamed to Windows Action Center (Windows Health Center and Windows Solution Center in earlier builds), which encompasses both security and maintenance of the computer. ReadyBoost on 32-bit editions now supports up to 256 gigabytes of extra allocation. The default setting for User Account Control in Windows 7 has been criticized for allowing untrusted software to be launched with elevated privileges without a prompt by exploiting a trusted application.[19] Microsoft's Windows kernel engineer Mark Russinovichacknowledged the problem, but noted that malware can also compromise a system when users agree to a prompt.[20] Windows 7 also supports images in RAW image format through the addition of Windows Imaging Component-enabled image decoders, which enables raw image thumbnails, previewing and metadata display in Windows Explorer, plus full-size viewing and slideshows in Windows Photo Viewer and Windows Media Center.[21]

Friday 7 December 2012

Thursday 6 December 2012


File:3-Tastenmaus Microsoft.jpgIn computing, a mouse is a pointing device that functions by detecting two-dimensionalmotion relative to its supporting surface. Physically, a mouse consists of an object held under one of the user's hands, with one or more buttons.
The mouse sometimes features other elements, such as "wheels", which allow the user to perform various system-dependent operations, or extra buttons or features that can add more control or dimensional input. The mouse's motion typically translates into the motion of a pointer on a display, which allows for fine control of a graphical user interface.

Mechanical mice

Mouse mechanism diagram.svg
Operating an opto-mechanical mouse.
  1. moving the mouse turns the ball.
  2. X and Y rollers grip the ball and transfer movement
  3. Optical encoding disks include light holes.
  4. Infrared LEDs shine through the disks.
  5. Sensors gather light pulses to convert to X and Y vectors.
German company Telefunken published on their early ball mouse, called "Rollkugel" (German for "rolling ball"), on October 2, 1968.[13] Telefunken's mouse was then sold commercially as optional equipment for their TR-440 computer, which was first marketed in 1968. Telefunken did not apply for a patent on their device. Bill English, builder of Engelbart's original mouse,[14] created a ball mouse in 1972 while working for Xerox PARC.[15]
The ball mouse replaced the external wheels with a single ball that could rotate in any direction. It came as part of the hardware package of the Xerox Alto computer. Perpendicular chopper wheels housed inside the mouse's body chopped beams of light on the way to light sensors, thus detecting in their turn the motion of the ball. This variant of the mouse resembled an inverted trackball and became the predominant form used withpersonal computers throughout the 1980s and 1990s. The Xerox PARC group also settled on the modern technique of using both hands to type on a full-size keyboard and grabbing the mouse when required.
Mechanical mouse, shown with the top cover removed. The scroll wheel is grey, to the right of the ball.
The ball mouse has two freely rotating rollers. They are located 90 degrees apart. One roller detects the forward–backward motion of the mouse and other the left–right motion. Opposite the two rollers is a third one (white, in the photo, at 45 degrees) that is spring-loaded to push the ball against the other two rollers. Each roller is on the same shaft as an encoder wheel that has slotted edges; the slots interrupt infrared light beams to generate electrical pulses that represent wheel movement. Each wheel's disc, however, has a pair of light beams, located so that a given beam becomes interrupted, or again starts to pass light freely, when the other beam of the pair is about halfway between changes.
Simple logic circuits interpret the relative timing to indica