BASIC COMPUTER COURSE (BCC)
I
KNOWING COMPUTER
Introduction
A Computer is an electronic device, which is used for a number of applications ranging from writing letters to reserve a ticket in a train. A Computer has several components like Keyboard, Mouse, Processor, Memory, Monitor and printer etc. Computer requires instructions to perform a particular task. A series of instructions is normally known as a program. Hardware and Software are the two terms we frequently use with reference to Computer. CPU, memory and peripheral devices (input and output devices) are generally referred to as Hardware whereas compiler. Interpreter and operating system are examples of software.
Objectives
1. Describe the various components of a Computer
2. Distinguish between Hardware and Software
3. Describe Applications of Computer
4. Connect Accessories to Computer
What is Computer?
Computer derives its name from the word Compute that means calculation. It can be said that Computer is a device used for calculation. Nowadays Computer
is not only limited to computation, but also used for making phone calls, maintaining databases,
listening songs, viewing movies etc, so a more formal definition of Computer
is required. Computer
is an electronic device that processes or transforms data into useful information by executing
a series of predefined instructions.
Figure 1- organization of computer
1.2.1 Basic application of ComputerWord Processing:
Word Processing software automatically corrects spelling and grammar mistakes. If the content of a document repeats you don’t have to type it each time. You can use the copy and paste features. You can printout documents and make several copies. It is easier to read a word-processed document than a handwritten one. You can add images to your document.
Internet
It is a network of almost all the computers in the world. You can browse through much more information than you could do in a library. That is because computers can store enormous amounts of information. You also have very fast and convenient access to information. Through E-Mail you can communicate with a person sitting thousands of miles away in seconds. There is chat software that enables one to chat with another person on a real-time basis. Video conferencing tools are becoming readily available to the common man.
Digital video or audio composition:
Audio or video composition and editing have been made much easier by computers. It no longer costs thousands of dollars of equipment to compose music or make a film. Graphics engineers can use computers to generate short or full-length films or even to create three-dimensional models. Anybody owning a computer can now enter the field of media production. Special effects in science fiction and action movies are created using computers.
Desktop publishing:
Computers in Medicine:
You can diagnose diseases. You can learn the cures. Software is used in magnetic resonance imaging to examine the internal organs of the human body. Software is used for performing surgery. Computers are used to store patient data.Mathematical Calculations:
Banks:
All financial transactions are done by computer software. They provide security,speed and convenience.
Travel:
One can book air tickets or railway tickets and make hotel reservations online. It reduced the time wastage and travel time for everyone.
Telecommunications:
Software is widely used here. Also all mobile phones have software embedded in them for maintaining customer details and also sending message, audio and video through the mobile software. Now a day's internet is available in the mobile phone itself.
Defence:
There is software embedded in almost every weapon. Software is used for controlling the flight and targeting in ballistic missiles. Software is used to control access to atomic bombs.
E-Learning:
Instead of a book it is easier to learn from E-learning software. It not only contains text also contain image and animation so it is very easy to understand everything.
Gambling:
We can gamble online instead of going to a casino.
Examinations:
We can give online exams and get instant results. You can check your examination results online.
Computers in Business:
Shops and supermarkets use software, which calculate the bills. Taxes can be calculated and paid online. Accounting is done using computers. One can predict future trends of business using artificial intelligence software. Software is used in major stock markets. One can do trading online. There are fully automated factories running on software.
Certificates:
Different types of certificates can be generated. It is very easy to create and change
layouts.
ATM machines:
The computer software authenticates the user and dispenses cash.
Marriage:
There are matrimonial sites through which one can search for a suitable groom or
bride.
News:
There are many websites through which you can read the latest or old news.
Classmates:
There are many alumni websites through which you can regain contact with your classmates.
Robotics:
Robots are controlled by software.
Washing Machines:
They operate using software.
Microwave Oven:
They are operated by software.
Planning and Scheduling:
Software can be used to store contact information, generating plans, scheduling appointments and deadlines.
Plagiarism:
Software can examine content for plagiarism.
Greeting Cards:
You can send and receive greetings pertaining to different occasions
Sports:
Software is used for making umpiring decisions. There are simulation software using which a sportsperson can practice his skills. Computers are also to identify flaws in technique.
Aeroplanes:
Pilots train on software, which simulates flying.
Weather analysis:
Supercomputers are used to analyze and predict weather.
Components of Computer System
Computer system is made up of a number of components. These are
1. Input devices
2. Memory unit
3. Central processing unit
4. Output devices
Figure 2 shows different components of Computer system.
Central Processing Unit (CPU)
The central processing unit (CPU) is where the actual processing takes place. This is where the calculations are performed and logical functions are carried out. The CPU retrieves its data and instructions from the main memory, processes the data according to the instructions and then stores the results back into the main memory or sends the processed information to the output subsystem. There are broadly three parts of Central
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arithmetic and logic operations are performed in Arithmetic and logic unit (ALU). A set of registers is used for temporarily storing data or instructions in CPU. It is to be noted that the central processor is controlled by the instructions it gets from main memory. The CPU retrieves and executes these instructions one by one until it completes a given task. Each instruction tells the CPU what to do (add, divide, move, and compare) and also tells it where to find the data to
be processed. CPU, memory all other components are connected through buses on Motherboard and are housed in a cabinet or system unit. The bus interconnects the different parts of the Computer so that information can move from one part of the Computer to another. In effects, the bus is a "highway'' over which electrical signals can travel. For example when the CPU retrieves an instruction from the main memory the electrical pulses representing that instructions are carried over the bus that connects the CPU and main memory. There are three different types of Buses used in Computer. These are Address bus, Data Bus and Control Bus.
Keyboard, Mouse and VDU
To solve a problem it is necessary to give data and instructions to the Computer. This can be done through input device. The keyboard is an example of an input device that accepts data and translates it into electronic signals. Both program (instructions) and data can be keyed in through it. In addition, certain commands to software can be given from the keyboard.
The keyboard consists of a set of keys. There is one key switch for each letter, number, symbol etc, much like a typewriter. Most common keyboard is called QWERTY keyboard as the alphabets in the first row are placed like commonly used typewriters. When a key is pressed, the key switch is activated. The keyboard has an electronic circuit to determine which key has been pressed. A code is then generated and sent to the computer. For example when you press the alphabet A on the keyboard, it is translated into the electronic code 0100001, which is sent to the Computer. Similarly, the number 0 is translated into the electronic code 00111001. So keyboard is one way to get data into the Computer. Detecting which key is pressed and generating the corresponding code is known as encoding. ASCII (American Symbolic Code for Information Interchange) is one such commonly used code.
Mouse
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Mouse is a pointing device which can be moved on a smooth surface to simulate the movement of cursor that is desired on the display screen. Mouse could be optical; offering quite and reliable operation, or mechanical which is cheaper. User can move the mouse; stop it at a point where the pointer is to be located and, with the help of buttons, and make selection of choices.
The mouse is not an alternative to the keyboard for entering data. Text and numbers still have to be keyed in, but selection from menus and drawings are easier with a mouse. There are 2 keys, 3 keys and scrolling facilities available in mouse.