Computer Basics

COMPUTER BASICS MULTI MEDIA CENTRE SREE NEELAKANTA GOVERNMENT SANSKRIT COLLEGE PATTAMBI

Outline Computer-Brief History Structure of Computer Hardware &Software Operating System Programme & Utilities

Brief History ●

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Blaise Pascal(1642) mechanical adding machine Charles Babbage(1842)Father of Modern Digital Computers First Generation(1942-55) Second Generation(1955-1964) Third Generation(1964-1975) Fourth Generation(1975-1989) Fifth Generation(1989)

First Generation ●

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Aiken, developed the Mark I in 1944 to ease this calculating burden. J. Presper Eckert and William Mauchley developed the ENIAC, Electronic Numerical Integrator and Calculator

ENIAC (Electronic Numerical Integrator And Computer) ●

. It occupied 167 sq m (1,800 sq ft), weighed more than 27,000 kg (60,000 lb), and contained more than 18,000 vacuum tubes. Roughly 2,000 of the computer’s vacuum tubes were replaced each month by a team of six technicians.

Second Generation ● ●

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In 1947, Bell Laboratories invented the transistor Texas Instruments improved the transistor in 1954 by using silicon rather than germanium. By using transistors in place of vacuum tubes, manufacturers could produce more reliable computers. Using transistors was also less expensive than building a computer with vacuum tubes.

Third Generation ● ●

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In 1958, the first integrated circuit was made This invention has led to the widespread use of computers today. Scientists found a way to reduce the size of transistors so they could place hundreds of them on a small silicon chip, about a quarter of an inch on each side.16 This enabled computer manufacturers to build smaller computers. At about this same time, the concept of a programming language was developed . In 1956, FORTRAN, the first programming language, was developed.19 Then in 1959, Grace Hopper invented COBOL.20

Fourth Generation ● ●

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In 1971 Intel created the first microprocessor The microprocessor was a large-scale integrated circuit which contained thousands of transistors. The transistors on this one chip were capable of performing all of the functions of a computer's central processing unit. The reduced size, reduced cost, and increased speed of the microprocessor led to the creation of the first personal computers. In 1976, Steve Jobs and Steve Wozniak built the first Apple computer in a garage in California.23 Then, in 1981, IBM introduced its first personal computer

Fifth Generation? ● ●

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Artificial Intelligence initiative by Japan's Ministry of International Trade and Industry, begun in 1982, to create a "fifth generation computer" Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. The goal of fifthgeneration computing is to develop devices that respond to natural language input and are capable of learning and self-organization

What is Computer? ●

A device that process data

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Data: Symbols that represents ,pics informations, sounds, objects Processing: The way computer manipulated data CPU processes data

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Characteristics of Computers: 

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Speed Accuracy High Storage Capacity Reliability Versatality Automation

Limitations of Computers : ● ● ●

Lack of Commonsense Inability to Correct Dependence on human assistance

Structure of Computer The diagram below shows a simple structure for the operation of a computer. Data is obtained for processing by the computer and then the results of the processing are output from the system.

Input

Process

Data Storage

Output

Types of Computers

Analog Computer ● Digital Computer ● Hybrid Computer ●

Basic Functions of Computer ● ● ● ● ●

INPUT DATA STORE DATA PROCESS DATA OUTPUT DATA CONTROLL ALL OF THE ABOVE

The von Neumann Model of the PC

Types of Computers

PDA Desktop Handheld (HPC)

Laptop

Workstation Tower

Input ●

Convert data analogue to digital

There are a wide range of input devices. Some of these input devices make use of human touch, light, magnetism, sound and control sensors. ● ●

Some examples are Key Board ,Mouse ,Scanner

Process ● ●

Analyse Data Processor (CPU)

The Central Processing Unit (CPU) can be considered the ‘brains’ of your computer. It consists of a single chip inside a computer that does most of the work. It takes the information from the input devices and instructions from memory, processes the information and then sends the result to storage or to an output device.

Intel ,AMD, Via

The power of the processor is indicated by its operating speed measured in Mega Hertz, (MHz).

magnification) is manufactured by the Intel Corporation. It contains more than three million transistors

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OUTPUT Output digital data to analog ● Some Examples are Monitors Printers Speakers ●

DATA STORAGE Copy data for later use ● The data will be in digital form Short term storage Computers use the RAM to store data temporarily while you work on it. Once you are happy with the job, you store it on the hard disk. ●

Long term storage Floppy disks, magnetic tape, etc can be used to offload confidential data from the hard disk. ● ●

Some examples are MEMORY, CDROM.HARD DISK, FLASH DISK

Types of Memory All computers have memory to store instructions and data. There are two main types of memory RAM (random access memory) This is a temporary storage for data. Typical RAM in a desktop PC may be 128 megabytes (MB). The RAM clears when your computer is switched off. ROM (read only memory) This is memory stored in a chip which is not lost when the power is turned off. On most PCs this memory is quite small. It contains the essential instructions for the computer to start.

Parts of PC A PC is a small desktop computer, normally made up of three basic groups: ●

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a base unit – containing processor, memory and disc drives a keyboard with a mouse and a monitor peripherals – additional devices connected to the computer.

INSIDE PC

Hardware&Software ●

Hardware- The electronic circuits, memory and input/output components of a computer system; the “tangible objects” Memory RAM Hard Disk/Floppy Disk/CD Tape CPU/Motherboard Modem Power Supply

Software A general term for

computer programs and documentation involved in the operation of the computer

COMPONENTS power supply CD-ROM drive

floppy drive cards

hard drive motherboard

COMPONENTS ●

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Motherboard – (body) acts as a manager for everything on the computer – connects all the other components together CPU – Central Processing Unit – (brain) this does all the work of computing Hard Drive – (long-term memory) holds all of the information that needs to be stored between uses of the computer

Mouse ● ●

Mouse (computer), a common pointing device A mouse is a pointing device that helps a user navigate through a graphical computer interface. Connected to the computer by a cable, it is generally mapped so that an onscreen cursor may be controlled by moving the mouse across a flat surface

KEY BOARD ●

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Keyboard, in computer science, a keypad device with buttons or keys that a user presses to enter data characters and commands into a computer. Function Keys, in computer science, any of the 10 or more keys labeled F1, F2, F3, and so on that are placed along the left side or across the top of a keyboard and are used for special tasks by different programs. A function key is in essence a “programmable” key whose meaning is defined by a program or, in some instances, by the user.

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Alt Key: keys that when pressed in combination with another key, gives the other key an alternative meaning Ctrl: Control key controlling functions of other keys

PORT ●

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An interface on a computer to which you can connect a device. Personal computers have various types of ports. Internally, there are several ports for connecting disk drives, display screens, and keyboards. Externally, personal computers have ports for connecting modems, printers, mice, and other peripheral devices. Almost all personal computers come with a serial RS-232C port or RS-422 port for connecting a modem or mouse and a parallel port for connecting a printer. On PCs , the parallel port is a Centronics interface that uses a 25pin connector. SCSI (Small Computer System Interface) ports support higher transmission speeds than do conventional ports and enable you to attach up to seven devices to the same port.

SCSI ●

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small computer system interface :A SCSI interface is used for connecting microcomputers to peripheral devices, such as hard disks and printers, and to other computers and local area networks PS2: SMALL ROUND PORT FOR NEW TYPE OF MOUSE AND KEYBOARD

BUS ●

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Bus in computer science, a set of hardware lines—wires— used for data transfer among the components of a computer system. A bus is essentially a shared highway that connects different parts of the system—including the microprocessor, disk-drive controller, memory, and input/output ports—and enables them to transfer information

The pathways that carry data on the motherboard are called buses

IDE & PCI ● ● ●

IDE: integrated drive electronics PCI: Short for Peripheral Component Interconnect VGA-video graphics array, a graphics display system for PCs

DISK DRIVES ●

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Disk Drive, in computer science, a device that reads or writes data, or both, on a disk medium. The disk medium may be either magnetic, as with floppy disks or hard disks; optical, as with CD-ROM (compact disc-read only memory) disks The main components of a disk drive are the motor, which rotates the disk; the read-write mechanism; and the logic board, which receives commands from the operating system to place or retrieve information on the disk

COMPONENTS ●

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RAM – Random Access Memory – (short-term memory) holds data and program instructions that the computer is currently using Floppy and CD-ROM drives – (mouth/ears) allow you to give data to the computer and take data away from the computer Power Supply – (heart) supplies power to all Network Card – (telephone) allows computer to talk to other computers over a wire

BUSES ●

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PC's buses are the fundamental data "highways" on the system board. The "first" bus is the system bus, which connects the CPU with RAM. In older designs it was a local bus. In newer designs this bus is called the front side bus (FSB). I/O buses connect the CPU to all other components, except RAM. Data are moved on the buses from one component to another, and data from other components to the CPU and RAM. The ISA bus, The PCI bus, The USB bus ,The AGP bus

data ●

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The signals, which we send each other to communicate, is data. Our daily data have many forms: sound, letters, numbers, and other characters (handwritten or printed), photos, graphics, film. All this data is in its nature analog, which means that it varies in type. The PC is an electric unit. Therefore, it can only deal with data, which are associated with electricity. – digital data

SOFTWARE Program ● DOS ● DATA ●

Computer Languages 

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A standardized communication technique for expressing instructions to a computer. Used to develop programs or software.

Types of Computer Languages : 1. Machine Languages 2. Low level Languages (Assembly Languages) 3. High level Languages

Introduction ●

ProgramA sequence of instructions directing a computer to perform a particular function; a statement of an algorithm in a programming language.

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Operating SystemA collection of programs for operating the computer. Operating systems perform housekeeping tasks such as input/output between the computer and peripherals, and accepting and interpreting information from the keyboard. Examples are WINDOWS,LINUX,MAC,DOS

Computer Hardware & Software 1. Software : Programs or sequence of instructions given to a computer to perform a particular task. Types of Software : 1. System Software : Programs needed to manage and support a computer system and its information processisng activities. Eg. Operating system, Programming Language Utility Programmes etc.

Computer Hardware & Software

1. Application Software : Programs designed to accomplish a particular task. That is program for specific application only Eg. Program for word processing, Spread sheet, Animation etc.

Operating System Operating system : An interface between the User and the Hardware. OS controls all componants of a computer system. Functions of Operating System : 1. Job Management 2. Resource Management 3. Data Management

Operating System....... Types of Operating System : 1. Single Program OS 2. Multiprogram OS 3. Time Sharing OS 4. Real Time OS 5. Multiprocessing OS

Operating System...... Popular Operating Systems : 1. DOS (Disk Operating System) 2. Windows (Version 1, 1.1......Vista) 3. Linux 4. UNIX -UNiplexed Information Computing

System (UNICS)-1970s

5. Mac.

Operating System...... CUI – Character user interface (Support only characters) (Eg. DOS) GUI – Graphic user interface (Graphical supporting like sound, video, image etc.) (Eg. Windows, Linux etc.) DMA - Direct Memory Access (less effort to OS)

DMI ●

The Desktop Management Interface (DMI) is a new method of managing computers in an enterprise. The main component of DMI is the Management Information Format Database, or MIFD (the DMI Pool Data). This database contains all the information about the computing system and its components.

BIOSBasic Input Output System ●

Booting Booting: #1ROM Bios instructions get executed. Hardware check is performed.

Memory Keyboard Hard/Floppy Disk and Controller

IO.SYS and MS.SYS system files get ready from hard/floppy disk.

Booting: #2-

Then CONFIG.SYS gets read and executed.

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Command.com is loaded into memory, then autoexec.bat file gets read and command is executed. At this point, the system will provide a “C:\>“ prompt. The computer is now up and running.

Some Terms Bits&Bytes ●

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Bits: binary digit, the smallest unit of information in a computer. A bit is represented by the numbers 1 and 0, which correspond to the states on and off, true and false, or yes and no. Bits are the building blocks for all information processing that goes on in digital electronics and computers Bits actually represent the state of a transistor in the logic circuits of a computer Bits are usually combined into larger units called bytes. A byte is composed of eight bits. The values that a byte can take on range between 00000000 (0 in decimal notation) and 11111111 (255 in decimal notation). This means that a byte can represent 28 (2 raised to the eighth power) or 256 possible states (0-255).

Number System ●

Each 0 or 1 is called a bit. Bit is an abbreviation of the expression Binary digit. It is called binary, since it is derived from the binary number system:

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0-1 bit

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1-1 bit

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0110-4 bit

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01101011-8 bit

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Numbers, as known in the decimal-system Same numbers in binary system

0 1 2 3 4 5 6 7 8

0 1 10 11 100 101 110 111 1000

Number System 1. Decimal System :  Consists of 10 numbers or symbols (0,1,2,3,4,5,6,7,8&9)  Base 10 system  Positional Value system (value depends upon position  Eg : 4672 – (‘4’is the MSD & 2 is the LSD) can be written as : (4X103)+ (6X102)+ (7X101)+ (2X100) = 4672

Number System.....cont.. 2. Binary System:  Consists of only 2 numbers or symbols (0,1)  Base 2 system  Positional Value system  Eg : 11can be written as : 1 0 1 1 (1X23)+ (0X22)+ (1X21)+ (1X20) = 11

Number System.....cont.. 3. Octal Number System:  Consists of only 8 possible digits (0,1,2,3,4,5,6&7)

Base 8 system 4. Hexa Decimal Number System:  Consists of only 16 possible digits (0,1,2,3,4,5,6,7,8,9 +A,B, etc.)  Base 16 system 

Bits & Bytes 1. Bits :  Short form of ‘Binary Digits’  Numbers in a binary number system. 2. Bytes :  Combination of 8 Bits makes one character (Byte)

Others Measures        

Kilobyte Megabyte Gigabyte Terabyte Petaabyte Exabyte Setabyte Yotabyte

(KB) (MB) (GB) (TB) (PB) (EB) (SB) (YB)

(210) = 1024 (220) = 1048576 (230) = 1073741824 (240) = 1099511627776 (250) = 1125899906842624 (260) = (270) = (280) =

Data Representation Standards 

BCD System (Binary Coded Decimal)

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ASCII System (American Standard Code for Information Interchange)

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EBCDIC System (Extended Binary Coded Decimal Interchange Code)

Challenge ● ●

Match the correct term with its definition. ___1. LAN (Local Area Network) A. Consists of 2 or more LANs. The computers are farther apart and are linked by telephone lines, dedicated telephone lines, or radio waves. ___2. WAN (Wide Area Network) B. Common source that provides shared services to other machines and manages resources in a network. ___3. Server C. A project that allowed researchers and military personnel to communicate with each other in an emergency. The foundation of the Internet. ___4. Clients D. Two or more connected computers sharing certain resources in a relatively small geographic location. ___5. ARPAnet E. Computers connected to a server and do not provide services to other computers.

kHz&Mhz ●

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Because computing is based on powers of 2, kilo- is most often used to mean 1024 (210). To distinguish between the two contexts, a lowercase k is often used to indicate 1000, an uppercase K for 1024. For example, kHz means 1000 hertz, but K or KB means 1024 bytes. Mega- (M), a prefix meaning 1 million (106). In computing, which is based on the binary (base-2) numbering system, mega- has a literal value of 1,048,576, which is the power of 2 (220) closest to one million.

computer networks: ●

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Local Area Network (LAN): A LAN is two or more connected computers sharing certain resources in a relatively small geographic location Wide Area Network (WAN): A WAN typically consists of 2 or more LANs. The computers are farther apart and are linked by telephone lines, dedicated telephone lines, or radio waves. The Internet is the largest Wide Area Network

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Computers running on the Internet communicate to each other using either the Transmission Control Protocol (TCP) or the User Datagram Protocol (UDP )

Servers & Clients ●

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All computers on the Internet can be lumped into two groups: servers and clients. In a network, clients and servers communicate with one another. A server is the common source that : –

Provides shared services and Manages resources.

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Independent computers connected to a server are called clients

INTERNET The Internet is a computer network made up of thousands of networks worldwide. No one knows exactly how many computers are connected to the Internet. It is certain, however, that these number in the millions and are growing. All computers on the Internet communicate with one another using the Transmission Control Protocol/Internet Protocol suite, abbreviated to TCP/IP. Computers on the Internet use a client/server architecture

COMPONENTS OF THE INTERNET ● ●

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WORLD WIDE WEB The World Wide Web (abbreviated as the Web or WWW) is a system of Internet servers that supports hypertext to access several Internet protocols on a single interface. In addition to these, the World Wide Web has its own protocol: HyperText Transfer Protocol, or HTTP. The World Wide Web was developed in 1989 by Tim Berners-Lee of the European Particle Physics Lab (CERN) in Switzerland

HYPERTEXT ●

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The operation of the Web relies primarily on hypertext as its means of information retrieval. HyperText is a document containing words that connect to other documents. Producing hypertext for the Web is accomplished by creating documents with a language called HyperText Markup Language, or HTML

E-MAIL ●

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Electronic mail, or e-mail, allows computer users locally and worldwide to exchange messages. Each user of e-mail has a mailbox address to which messages are sent. Messages sent through e-mail can arrive within a matter of seconds. A powerful aspect of e-mail is the option to send electronic files to a person's e-mail address. Non-ASCII files, known as binary files, may be attached to e-mail messages. These files are referred to as MIME attachments.MIME stands for Multimedia Internet Mail Extension, and was developed to help e-mail software handle a variety of file types.

TELNET ●

Telnet is a program that allows you to log into computers on the Internet and use online databases, library catalogs, chat services, and more. There are no graphics in Telnet sessions, just text. To Telnet to a computer, you must know its address. This can consist of words (locis.loc.gov) or numbers (140.147.254.3).

FTP ●

FTP stands for File Transfer Protocol. This is both a program and the method used to transfer files between computers. Anonymous FTP is an option that allows users to transfer files from thousands of host computers on the Internet to their personal computer account. FTP sites contain books, articles, software, games, images, sounds, multimedia, course work, data sets, and more.

E-MAIL DISCUSSION GROUPS ●

One of the benefits of the Internet is the opportunity it offers to people worldwide to communicate via e-mail. The Internet is home to a large community of individuals who carry out active discussions organized around topicoriented forums distributed by e-mail. These are administered by software programs. Probably the most common program is the listserv

USENET NEWS ●

Usenet News is a global electronic bulletin board system in which millions of computer users exchange information on a vast range of topics. The major difference between Usenet News and e-mail discussion groups is the fact that Usenet messages are stored on central computers, and users must connect to these computers to read or download the messages posted to these groups. This is distinct from e-mail distribution, in which messages arrive in the electronic mailboxes of each list member.

CHAT & INSTANT MESSAGING ●

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Chat programs allow users on the Internet to communicate with each other by typing in real time. They are sometimes included as a feature of a Web site, where users can log into the "chat room" to exchange comments and information. Internet Relay Chat (IRC) is a service through which participants can communicate to each other on hundreds of channels A variation of chat is the phenomenon of instant messaging. With instant messaging, a user on the Web can contact another user currently logged in and type a conversation.

PAGES ON THE WEB ●

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The World Wide Web consists of files, called pages or Web pages, containing information and links to resources throughout the Internet. Access to Web pages may be accomplished by: – – –

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Entering an Internet address and retrieving a page directly Browsing through pages and selecting links to move from one page to another Searching through subject directories linked to organized collections of Web pages Entering a search statement at a search engine to retrieve pages on the topic of your choice

RETRIEVING DOCUMENTS ON THE WEB: ●

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URL&DNS URL stands for Uniform Resource Locator. The URL specifies the Internet address of a file stored on a host computer connected to the Internet. Every file on the Internet, no matter what its access protocol, has a unique URL. URLs are translated into numeric addresses using the Domain Name System (DNS). The DNS is a worldwide system of servers that stores location pointers to Web sites. The numeric address, called the IP (Internet Protocol) address, is actually the "real" URL.

Anatomy of a URL ● ●

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This is the format of the URL: protocol://host/path/filename For example, this is a URL on the Web site of the U.S. House of Representatives: http://www.SNGSCOLLEGE.INFO/MAG/INDEX.html Structure of this URL: Protocol: http Host computer name: www Second-level domain name: SNGSCOLLEGE Top-level domain name: INFO Directory name: MAG File name: INDEX.HTML

Several top-level domains (TLDs) ● ● ● ● ● ● ●

Com-commercial enterprise Edu-educational institution Gov- government Net-network access provider Org-usually nonprofit organizations In-India Info-Informative

HOW TO ACCESS THE WORLD WIDE WEB: ●

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To access the World Wide Web, you must use a Web browser. A browser is a software program that allows users to access and navigate the World Wide Web. There are two types of browsers: Graphical&Text Graphical:Internet Explorer,Opera,Mozila, Netscape Text:Lynx

Extending the Browser: Plug-Ins ●

Software programs may be configured to a Web browser in order to enhance its capabilities. When the browser encounters a sound, image or video file, it hands off the data to other programs, called plug-ins, to run or display the file.

Beyond Plug-Ins: Active X ●

ActiveX is a technology developed by Microsoft which make plug-ins less neccesary. ActiveX offers the opportunity to embed animated objects, data, and computer code on Web pages. A Web browser supporting ActiveX can render most items encountered on a Web page.

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Today's World Wide Web presents an ever-diversified experience of multimedia, programming languages, and realtime communication

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Streaming video, Shockwave and Macromedia Flash, Live cams Active Server Pages (ASP). CGI (Common Gateway Interface) Java/Java Applets: Java

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VRML: VRML (Virtual Reality Modeling Language XML: XML

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(eXtensible Markup Language) ●

Real-Time Communication :Chat

Current Trends: Blogs and RSS ●

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Blog is an easy-to-create Web site that allows users to share their thoughts with the world managed by a lightweight content management system. The word "blog" comes from "Weblog" because a blog consists of a signed and dated log of individual postings. RSS: RSS allows people to place news and other announcement-type items into a simple XML format that can then be pushed to RSS readers and Web pages. The initials RSS can stand for different things, including Rich Site Summary or Really Simple Syndication.

Three major resources for locating Internet materials ● ● ● ●

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subject directory the search engine content on the deep Web. A subject directory is a service that offers a collection of links to Internet resources submitted by site creators or evaluators and organized into subject categories. Directory services use selection criteria for choosing links to include, though the selectivity varies among services. Most directories are searchable. There are two basic types of directories: academic and professional directories often created and maintained by subject experts to support the needs of researchers, and directories contained on commercial portals that cater to the general public and are competing for traffic

SEARCH ENGINES ●

A search engine is a searchable database of Internet files collected by a computer program (called a wanderer, crawler, robot, worm, spider). Indexing is created from the collected files, e.g., title, full text, size, URL, etc. There is no selection criteria for the collection of files, though evaluation can be applied to the ranking of results.

search engine service or a search service. ● ●

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it consists of three components: Spider: Program that traverses the Web from link to link, identifying and reading pages Index: Database containing a copy of each Web page gathered by the spider Search engine mechanism: Software that enables users to query the index and that usually returns results in relevancy ranked order Search engines Eg:Google,Yahoo.MSN,Rediff

DEEP WEB ●

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The deep Web consists of information stored in searchable databases mounted on the Web. Information stored in these databases is accessible by user query. These databases usually search a targeted topic or aspect of a topic, though entire Web sites may be contained within a database. Search engine spiders cannot or will not index this information. The deep Web also consists of multimedia and image files, and files created in non-standard file types such as Portable Document Format (PDF).

In brief ●

There are a number of basic ways to access information on the Internet: – – – – –

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Go directly to a site if you have the address Browse Explore a subject directory Conduct a search using a Web search engine Explore the information stored in live databases on the Web, known as the "deep Web" Join an e-mail discussion group or Usenet newsgroup