Introduction_to_Computers.pptx

1 Introduction to Computers Dr. Kushagra kashyap Assistant Professor DES Pune University [email protected]  2 What is a Computer? A comput...

1 Introduction to Computers Dr. Kushagra kashyap Assistant Professor DES Pune University [email protected]  2 What is a Computer? A computer is an electronic device, operating under the control of instructions (software) stored in its own memory unit, that can accept data (input), manipulate data (process), and produce information (output) from the processing. Generally, the term is used to describe a collection of devices that function together as a system.  History of Computer 3 Before the 1500s, in Europe, calculations were made with an abacus The abacus was an early aid for mathematical computations. Its only value is that it aids the memory of the human performing the calculation. A skilled abacus operator can work on addition and subtraction problems at the speed of a person equipped with a hand calculator (multiplication and division are slower). In 1642, Blaise Pascal (French mathematician, philosopher) invented a mechanical calculator called the Pascaline In 1671, Gottfried von Leibniz (German mathematician, philosopher) extended the Pascaline to do multiplications, divisions, square roots None of these machines had memory, and they required human intervention at each step  4 In 1822 Charles Babbage (English mathematician, philosopher), sometimes called the “father of computing” built the Difference Engine Machine designed to automate the computation (tabulation) of polynomial functions (which are known to be good approximations of many useful functions) – Based on the “method of finite difference” – Implements some storage Later Babbage designed the Analytical Engine, but he died before he could build it – It was built after his death, powered by steam  Generation of Computers 5 Generation 0: Mechanical Calculators Generation 1: Vacuum Tube Computers First Generation (1946-59) Generation 2: Transistor Computers Second Generation(1957-64) Generation 3: Integrated Circuits Third Generation(1965-70) Generation 4: Microprocessors Fourth Generation(1970-90) Fifth Generation(1990 till date)  6 Generation 1 : ENIAC The ENIAC (Electronic Numerical Integrator and Computer) was disclosed in 1946: the first all-electronic, general-purpose digital computer  7 The use of binary Claude Shannon (the father of “information theory”) had proposed that the use of binary Arithmetic and Boolean logic should be used with electronic circuits The Von-Neumann architecture CPU Memory I/O System  8 Generation 2: IBM7094  9 Generation 3: Integrated Circuits Seymour Cray created the Cray Research Corporation Cray-1: 160 million instructions per seconds and 8 Mbytes of memory  10 Generation 4: VLSI Improvements to IC technology made it possible to integrate more and more transistors in a single chip SSI (Small Scale Integration): 10-100 MSI (Medium Scale Integration): 100-1,000 LSI (Large Scale Integration): 1,000-10,000 VLSI (Very Large Scale Integration): >10,000 Microprocessors  11 Generation 5 Generation 5 computers are based on Artificial intelligence. Such devices are still in developments like: Voice recognition Quantum computing Bio computing Nano technology Learning Natural languages  12 Parts of a computer system Monitor Keyboard Speaker (output) (input) (output) System unit (processor, memory…) Printer (output) Storage devices (CD-RW, Floppy, Hard disk, zip,…) Mouse (input) Scanner (input) What Does A Computer Do? 13 Computers can perform four general operations, which comprise the information processing cycle. Input Process Output Storage  14 Data and Information ▪ All computer processing requires data, which is a collection of raw facts, figures and symbols, such as numbers, words, images, video and sound, given to the computer during the input phase. ▪ Computers manipulate data to create information. Information is data that is organized, meaningful, and useful. ▪ During the output Phase, the information that has been created is put into some form, such as a printed report. ▪ The information can also be put in computer storage for future use.  15 Why is A Computer So Powerful? ▪The ability to perform the information processing cycle with amazing speed. ▪Reliability (low failure rate). ▪Accuracy. ▪Ability to store huge amounts of data and information. ▪Ability to communicate with other computers. How does a Computer know what to 16 do? ▪It must be given a detailed list of instructions, called a computer program or software, that tells it exactly what to do. ▪Before processing a specific job, the computer program corresponding to that job must be stored in memory. ▪Once the program is stored in memory the compute can start the operation by executing the program instructions one after the other. What Are The Primary Components Of A Computer ? ▪Input devices. ▪Central Processing Unit (containing the control unit and the arithmetic/logic unit). ▪Memory. ▪Output devices. ▪Storage devices. 17  18 Input Devices ▪Keyboard. ▪Mouse.  Keyboard The most commonly used input device is the keyboard on which data is entered by manually keying in or typing certain keys. A keyboard typically has 101 or 105 keys. 19  Mouse Mouse is a pointing device which is used to control the movement of a mouse pointer on the screen to make selections from the screen. A mouse has one to five buttons. The bottom of the mouse is flat and contains a mechanism that detects movement of the mouse. 20 Central processing Unit The central processing unit (CPU) contains electronic circuits that cause processing to occur. The CPU interprets instructions to the computer, performs the arithmetic and logical processing operations, and causes the input and output operations to occur. It is considered the “brain” of the computer. 21  Memory Memory also called Random Access Memory or RAM (temporary memory) is the main memory of the computer. It consists of electronic components that store data including numbers, letters of the alphabet, graphics and sound. Any information stored in RAM is lost when the computer is turned off. Read Only Memory or ROM is memory that is etched on a chip that has start-up directions for your computer. It is permanent memory. 22  Output Devices Output devices make the information resulting from the processing available for use. The two output devices more commonly used are the printer and the computer screen. The printer produces a hard copy of your output, and the computer screen produces a soft copy of your output. 23  Storage Devices Auxiliary storage devices are used to store data when they are not being used in memory. The most common types of auxiliary storage used on personal computers are floppy disks, hard disks and CD-ROM drives. 24  Floppy Disks A floppy disk is a portable, inexpensive storage medium that consists of a thin, circular, flexible plastic disk with a magnetic coating enclosed in a square-shaped plastic shell. 25  26 ▪The disk’s storage locations are divided into pie- shaped sections called sectors. ▪A sectors is capable of holding 512 bytes of data. ▪A typical floppy stores data on both sides and has 80 tracks on each side with 18 sectors per track. USB Pen Drive Digital Versatile Disc (Universal Serial Bus) Capacity 4.7GB Capacity 2/4/8/16 GB  27 Hard Disks ▪Another form of auxiliary storage is a hard disk. A hard disk consists of one or more rigid metal plates coated with a metal oxide material that allows data to be magnetically recorded on the surface of the platters. ▪The hard disk platters spin at a high rate of speed, typically 5400 to 7200 revolutions per minute (RPM). ▪Storage capacities of hard disks for personal computers range from 80 GB to 500 GB (one billion bytes are called a gigabyte) and more. Classification of Computers 28 ▪Personal Computers ▪Notebook/Laptops ▪Mini and Microcomputers ▪Workstations ▪Servers ▪Mainframes ▪Supercomputers Personal Computers 29 ▪Used at home ▪Used in Education, Institution and Organizations as nodes ▪Can perform typical activities like documentation, playing games, surfing web to more complex activities as programming, design, DTP etc.  Notebook / Laptops 30 ▪ Same as PCs in functionality ▪ More Compact, Portable ▪ Less Power requirement, operated on battery/s ▪ Less capacity compared to PCs ▪ Maintenance and actually are costlier compared to PCs ▪ Theft prone Laptop: A portable computer small enough to use on one's lap. Notebook: A light, portable computer that is generally thinner than a laptop. Even according to Webopedia, laptop computers are more frequently called notebook computers, though technically laptops are somewhat smaller in size than notebooks.  Mini and Microcomputers 31 ▪ Microcomputer is also called Personal Computer ▪ Minicomputers are in between mainframes and Microcomputers. They are also called midrange computers ▪ They are maintained by some organization Ex. PDP – 11 Workstations 32 ▪ They are similar to PCs but with more memory and a high speed processor ▪ They are intended to support network operating systems and network applications. ▪ They are used in architectural design, video editing, animations etc. Servers 33 ▪ A server is one for which many PCs are connected. ▪ It has large capacity secondary storage and more memory ▪ They host, like workstations, network servers and operating systems ▪ They avoid duplicate installation of applications and all users will access to a common copy of the program Mainframes 34 ▪ Large computers both in terms of physical size as well as computations ▪ They support huge numbers of users ▪ Basically used to store and process huge amount of data ▪ Not all organizations can offered to maintain one mainframe. Take service of one vendor Supercomputers 35 ▪ Used in scientific and engineering applications those handling huge data and do a great amount of computation. ▪ Extremely fast in operation (@ 1 trillion operations/second) ▪ Fastest, costliest and powerful computer available today ▪ Application involves, weather forecasting, military applications, electronic design etc.  Computer Software Computer software is the key to productive use of computers. Software can be categorized into two types: Operating system software Application software. 36  Operating System Software 37 Operating System is a software, which makes a computer to actually work. It is the software the enables all the programs we use. The OS organizes and controls the hardware. OS acts as an interface between the application programs and the machine hardware. Examples: Windows, Linux, Unix and Mac OS, etc., DOS 38  Windows 39 ▪Windows: The primary PC operating system developed by Microsoft Corporation ▪Windows 1.0 through Windows 3.x: Operating environments for DOS, not full-fledged operating systems ▪Windows 95 and Windows 98: Used a similar GUI to the one used with Windows 3.x ▪Windows 98 Second Edition (SE): Update to Windows 98, released in 1999; still an installed base of older PCs running Windows 98 SE ▪Windows NT (New Technology): first 32-bit version of Windows designed for high-end workstations and servers  Windows 40 ▪ Windows, cont. ▪ Windows Me (Millennium Edition): designed for home PCs, improved home networking and a shared Internet connection ▪ Windows 2000: replaced Windows NT; was geared towards high-end business workstations and servers, support for wireless devices ▪ Windows XP: Replaced both Windows 2000 and Windows Me ▪ Based on Windows NT technology ▪ More stable and powerful than earlier versions of Windows ▪ Newest features related to multimedia and communications  Windows 41 ▪Windows Vista ▪Features the Aero visual interface ▪Transparency and animations ▪Live Thumbnails ▪The Vista Start menu is more streamlined ▪Built-in security features ▪Improved networking ands multimedia ▪Additional features ▪Sidebar, Instant Search, etc. ▪Hardware requirements for Vista have increased over earlier versions of Windows ▪Four editions (Home Basic, Home Premium, Business, and Ultimate) Windows Vista 42  Windows 7 With the new Aero features of Windows 7, it's easier to get work done. Desktop and Taskbar ▪ You have more control over the arrangement of your desktop with the removal of the sidebar, which was introduced in Windows Vista. ▪ Gadgets can still be placed on the desktop, wherever you want them. “START” SCREEN (Windows 8) 44 45  Windows 46 ▪ Windows Server: Server version of Windows ▪ Windows Server 2012: Most recent version ▪ Includes a variety of services ▪ Web platform ▪ Support for virtualization ▪ New security tools ▪ Streamlined management tools ▪ Windows Home Server: New operating system based on Windows Server ▪ Provides services for a home network ▪ Provides access to shared files ▪ Can back up all devices on the network automatically  UNIX 47 ▪UNIX: Operating system developed in the late 1960s for midrange servers and mainframes ▪Many variations of UNIX are in use today ▪Multiuser, multitasking operating system ▪More expensive, requires a higher level of PC knowledge, and tends to be harder to install, maintain, and upgrade than most other operating systems ▪“UNIX” initially referred to the original UNIX operating system, now refers to a group of similar operating systems based on UNIX ▪Single UNIX Specification: A standardized UNIX environment  Linux 48 ▪ Linux: Version (flavor) of UNIX available without charge over the Internet ▪ Increasingly being used with PCs, servers, mainframes, and supercomputers ▪ Is open-source software: has been collaboratively modified by volunteer programmers all over the world ▪ Originally used a command line interface, most recent versions use a GUI ▪ Strong support from mainstream companies, such as Sun, IBM, HP, and Novell ▪ Used on PCs, mainframes, and consumer appliances ▪ Growing integration between Linux and other operating systems is a recent development Several Linux Distributions, commonly called “distros” ▪ Ubuntu Linux , Red Hat Enterprise Linux, Linux Mint, Debian, Fedora Linux 49  Netware and Solaris 50 ▪ NetWare: Widely used operating system for PC-based networks ▪ Developed by Novell ▪ Competes directly with the server versions of Windows, Mac OS, and Linux ▪ Newest version (NetWare 6.5) incorporates Open Enterprise Server ▪ Solaris: UNIX-based operating system developed by Sun Microsystems for Sun computers ▪ Can run on desktop systems and servers, as well as on some supercomputers  Utility Programs 51 ▪ Utility program: Type of software that performs a specific task, usually related to managing or maintaining the computer system ▪ Many utilities are built into operating systems (for finding files, viewing images, backing up files, etc.) ▪ Utilities are also available as stand-alone products and as security suites  Application Software Application Software consists of programs that tell a computer how to produce information. Some of the more commonly used packages are: Word processing Electronic spreadsheet Database Presentation graphics 52  53 Thanks