COMPUTER BASICS:

What is a computer?A computer is an electronic device which accepts input from keyboard ,stores it in the memory by performing arithmetic and logical operations and displays the output on the screen.

A computer is a device which is capable of performing billions of operations and make millions of decisions per second at a marvelous speed .

Eg: A computer can perform million of additions per seconds which a human requires nearly a life time to complete the same number operations using a desk calculator .

Where is computer used these days?Computers are used almost at places these days,

1.Computers are used in office work for storage of data, for creating and managing database using access, for slide presentation etc.

2.Computers are used at scientific laboratories for analysis of research information.

3.Computers are used for reservation purposes at railways ,airways, cinema hall etc.

4.Computers are used at hospitals for diagnosing purpose , used in various operations like eye, heart, brain operations etc.

5.Computers are used for publication works.

6.Computers are used at educational institutions like schools , colleges ,universities for maintaining records ,database etc.

7.Computers are used in banks for money transaction purposes .

What are the basic operations of computer? There are four basic operations of a computer. They are,

1.Input:Accepting data that has been represented in a way that computer can use.

2.Processing:Performing arithmetic and logical calculations.

3.Output:Displaying result

4.Storage:Storing result for later/future re-use

What are the basic components of a computer?

The basic component of a computer system are ,

Input

Memory unit

Control unit

ALU

Output

What are the basic components of a computer?Input: They convert data into electronic machine readable form (binary form ) or convert letters ,numbers into strings of binary data.

Eg : Keyboard, mouse , touch screen, optical scanner etc.

Memory unit: Computer store data internally (in chips) and externally (on storage devices).

Internally computer store data in silicon ram chips that are mounted directly on computer main circuitry .

These ram chips contains millions of electronic switches that are sensitive to changes in electric current.

There are two types of RAM chips : static and dynamic

Static ram chip hold data as long as current flows through the circuit, Whereas dynamic ram chips need high or low voltages applied at regular intervals-every two milliseconds or so if they are not to lose their information.

Another type of internal memory consisting of silicon ROM (read only memory) chip on which all the

switches are already set.

The patterns on these ROM chips contains programs, commands, data that the computer needs to function correctly.

RAM chips are like piece of paper that can be written on, erased, and used again.

ROM chips are like a text book with it’s words already set on each paper.

Both RAM and ROM chips are linked by circuitry to the cpu.

What is CPU (central processing unit) and why it is important?Device consisting of electronic circuitry that executes instructions to process data.

CPU is important because it is considered as brain of computer.

CPU performs arithmetic and logical calculations and controls the operations of other part of computer.

CPU may be single silicon chip or a

series of chips .

A chip contains thousands of electronic switching circuits.

The CPU consists of ALU, REGISTERS, CONTROL UNIT, INTERNAL BUS.

ALU carries arithmetic and logical operations .

Registers store data and keep track of operations.

Control unit controls and regulates various operations.

Internal Bus connects the unit of the CPU with each other and with external components of system.

What is chip and why it is important?A chip is a tiny piece of silicon that contains millions of miniature electronic circuits used to process data.

Chips have made possible the development of small computer.

Why is computer important?

Computer greatly speed up problem solving and other tasks, increasing user’s productivity.

Easy to create presentations.

Easy to solve complex computations

Easy to communicate and share information from one computer to other computer and users to users.

Easy to store data in a data base for long period of time provided security.

Easy to make analysis of researched data.

What is hard disk drive and why it is important?It is a storage device that stores billions of characters of data on a non-removable disk platters inside the computer case.

Hard disk is important because it holds much more data than diskette. Nearly all computers use hard disk as their principal secondary storage medium.

What is hardware of computer?Physical part of the computer like mouse, monitor, keyboard, CPU etc

The electronic , magnetic, mechanical devices of a computer are known as hardware.

What is a software and what are the two different types of computer software's ?A software is collection of programs which is used to perform a particular task.

Program: Is a list of instructions, written in a programming language that tell computer how to perform operations in order to accomplish a task.

or

Computer process data under control set of instructions called computer programs

or

List of instructions that tells computer what to do.

There are two types of software’s ,

Application software

System software

Application software: Software that allows to write documents, do spreadsheets etc

Enables you to perform specific task- perform work, solve problems etc

Eg: word processing, spreadsheets, database manager, graphics, communications packages.

System software: Helps computer perform essential operating system tasks and enables the application software to run.

System software consists of several programs .

The most important is operating system the master control program that runs the computer.

System software is very important because application software cannot run without system software.

What is internet?Mother of all networks .

Internet is a world wide network that connects hundreds of thousands of smaller networks .

Internet connects large geographical areas like WAN (wide area network) or network of networks.

What is www (world wide web)?An interconnected systems of computers all over the world that store information in multimedia form.

Multimedia: “from multiple media” , A technology that presents information in more than one medium, such as text, still images, moving images, sounds ,animations.

What are the different types of computers?The different types of computers are ,

1. Super computer

2. Mainframe computer

3. Workstation computer

4. Microprocessor

5. Microcontroller

What is a super computer?A super computer is a high capacity computer with hundreds of thousands of processors that can perform over 1 trillion calculations per second.

Super computers are used for research purposes , designing air planes, oil explorations , whether forecasting, modeling molecules, breaking codes, simulating explosion of nuclear bombs, creating film animations.

Is the fastest calculating device ever invented.

Can cost up to $85 million.

Looks like rows of refrigerator size boxes.

A supercomputer named ASCI white (accelerated strategic computing initiative white) developed by IBM

Has 8192 processors

Can process 12.3 trillion

operations per second.

Uses 83 miles of wiring.

It weighs 106 tons.

It has 97,000 times the memory of a 64-megabyte micro computer.

It has 16,000 times the secondary storage capacity of a 10-gigabyte micro computer hard disk.

It takes up to 12,000 square feet of space .

What is mainframe computer?Mainframes are used by large organizations that need to process millions of transactions like airline, insurance companies, universities, banks.

For processing of millions of transactions.

Mainframes process millions of instructions per second.

Can cost around $5000-$200,000 and vary in size from small , to medium, to large, depending up on their use.

What are workstation computers?Workstations are expensive, powerful computer used for complex scientific, mathematical and engineering calculations and for computer aided design and computer aided manufacturing.

Workstations are used for designing air planes fuse- lages , prescription drugs, movie special effects.

Workstations are more popular for their graphics capabilities which are used to breathe three-dimensional life into movies such as Jurassic park 3 and pearl harbor.

What are micro computers?Also called personal computers

Cost $500-$5000

Can fit to a desk or on a desktop, can be carried around.

They are standalone machines or are connected to a computer network, eg: lan

Types of microcomputers,

Desktop pc’s

Tower pc’s

Laptops or notebooks

PDA (personal digital assistants-palmtops

What are micro controllers?Also known as embedded computers are tiny specialized microprocessors installed in smart appliances and automobiles.

These microcontrollers enable microwave, ovens Eg: to store data about how long to cook your potatoes and at what temperature.

What is processor chip?A processor chip is a tiny piece of silicon that contains millions of miniature electronic circuits (IC’s) that executes instructions to process data.

Speed is expressed in “MHz (megahertz) “, millions of processing per second or “GHz (gigahertz)”, billions of processing per second.

What is memory chip?Memory chips are also known as RAM (random access memory ) chips.

Represents primary storage

They hold data before processing and information after processing ,before it is sent along to an output or storage device.

What is mother board?Also know as “system board”.

Mother is main circuit board

in computer.

This is a board to which every thing else-such as keyboard , mouse, printer-attaches through connectors (called ports) in the back of computer.

The processor chip and memory chip

are also installed on the motherboard.

It has extension slots for expanding

the pc’s capabilities –which give you

places to plug in additional circuit boards , such as for video , sound, communications (modem).

What are the three directions in which computer developed?The three directions of computer development are:

1.Miniaturization

2.Speed

3.Affordability

Miniaturization deals with minimization of computers.

The development of computer generations was due to invention of an electronic device

At 1st Generation computer:

ENIAC (electronic numerical integrated and calculator)

Used VACCUM TUBES (an electronic device) to store data in it. Drobage – large, expensive, difficult to maintain , more power consumption

At 2nd Generation computer:

Computer entered into 2nd generation with an invention of electronic device-transistors.

Several vaccum tubes were able to accommodate in small, fast, reliable, transistor

A transistor is a small device used as a gateway to transfer electrical signals along predetermined paths (circuits).

At 3rd Generation computer:

The development of 3rd generation of computer was due to another electronic device –tiny integrated circuits (IC’s).

Again, several transistors were accommodated in tiny integrated circuit (IC).

IC’s are entire collection of electrical circuits or pathways that are now etched on tiny squares (chips) of silicon half the size of your thumbnail

At 4th Generation computer:

The development of 4th generation of computers was due another electronic device –microprocessor

Again, several IC’s were accommodated in a single microprocessor chip made up of silicon.

The miniaturized processor or microprocessor in personal desktop today can perform calculations that once required a computer filling entire room.

At 5th Generation computer:

The introduction to fifth generation of computers was not due to any electronic device.

Instead, the development of fifth generation of computer was based on “HUMAN BEHAVIOR” as “ ARTIFICAL INTELLIGENCE”.