BASIC COMPUTER CONCEPTS

1. BASIC COMPUTER CONCEPTS MADE BY: SIR NASEEM AHMED KHAN DOW VOCATIONAL & TECHNICAL TRAINING CENTRE

2. What is a computer? An electronic device, operating under the control of instructions stored in its own memory unit, that can accept data (input), manipulate the data according to specified rules (process), produce information (output) from the processing, and store the results for future use.

3. Advantages of Computers • Speed • Storage • High Accuracy • Versatility • Diligence • Automatic Operation • Obedience • Decision Making Capability

4. Ages of Computer • At the early age people used pebbles, stones, sticks, scratches, symbols and finger tips to count, which were later replaced by numbers. • The history of computing is divided into three ages during which man invented and improved different types of calculating machines. These ages are, • Dark age - 300 BC to 1890 • Middle age - 1890 AD to 1944 • Modern age - since 1944 AD

5. Classification of Computers According to Purpose General Purpose Computers: General purpose computers are designed to solve a large variety of problems. The different programs can be used to solve many problems. Most digital computers are general purpose computers and used in business and commercial data processing.

6. Classification of Computers According to Purpose . 2 Special Purpose Computers • The special purpose computers are designed to solve specific problems. The computer program for solving a specific problem is built right into the computer. Most analog computers are special purpose computers. These special purpose computers are widely used in industrial robotics.

7. Types of Computers . 1 Analog Computers A computer that uses moving parts to show changing information. The word “Analog” means continuously varying in quantity. The voltage, current, sound, speed, temperature, pressure etc. values are examples of analog data. The thermometer is an example of analog device because it measures continuously the length of a mercury column. Another example of analog computer is the analog clock because it measures the time by means of the distance continuously covered by the needle around a dial.

8. Types of Computers . 2 Digital Computers The word “Digital” means separate. It refers to binary system, which consists of only two digits, i.e. 0 and 1. Digital data consists of binary data represented by OFF (low) and ON (high) electrical pulses. These pulses are increased and decreased in discontinuous form rather than in continuous form. In digital computers, quantities are counted rather than measured. A digital computer operates by counting numbers or digits and gives output in digital form.

9. Types of Computers 3. Hybrid Computers The hybrid computers have best features of both analog and digital computers. These computers contain both the digital and analog components. In hybrid computers, the users can process both the continuous (analog) and discrete (digital) data.

10. Classification of Computers According to Size • Super Computers: Supercomputer a state-of-the-art, extremely powerful computer capable of manipulating massive amounts of data in a relatively short time. Supercomputers are very expensive and are employed for specialized scientific and engineering applications that must handle very large databases or do a great amount of computation, among them meteorology, animated graphics, nuclear energy research and weapon simulation, and petroleum exploration.

11. Classification of Computers According to Size . 2Main Frame Computers: The most expensive, largest and the most quickest or speedy computer are called mainframe computers. These computers are used in large companies, factories, organizations etc. the mainframe computers are the most expensive computers, they cost more than 20 million rupees. In this computers 150 users are able to work on one C.P.U

12. Classification of Computers According to Size . 3 Mini Computers A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems (mainframe computers) and the smallest single-user systems (microcomputers or personal computers). Mini computers are smaller than mainframes, both in size and other facilities such as speed, storage capacity and other services. They are versatile that they can be fitted where ever they are needed.

13. Classification of Computers According to Size . 4 Micro Computers A microcomputer is a computer with a microprocessor as its central processing unit. They are also called “computer of a chip” because its entire circuitry is contained in one tiny chip. They are physically small compared to mainframe and minicomputers. Micro computers of todays are equivalent to the mini computers of yesterday in terms of performing and processing.

14. What does a computer do? Processor Control Unit/Arithmetic Logic Unit • Input • Process • Output • Storage Input Devices Output Devices Memory Storage Devices Information Processing Cycle

15. Hardware All the physical parts which makes up a computer system called hardware i.e. all the devices or peripherals which performs the data processing operations. e.g. 1. Input devices 2. Output devices SOFTWARE Software consists of programs and routines whose purpose is to make the computer useable for the user. These software normally supplied by computer manufacturers or software manufacturers Components of a Computer System

16. Input Devices • Any hardware component that allows you to enter data, programs, commands, and user responses into a computer • Input Device Examples • Keyboard • Mouse • Mic • Scanner • Joystick

17. Output Devices • Output devices make the information resulting from processing available for use • Output Device Examples • Printers • Impact • Nonimpact • Photo • Display Devices • CRT • LCD • Speakers

18. Backing Storage Backing storage devices are where you can store data permanently. This means that data is held when the computer is switched off and can be loaded onto a computer system when required. These devices are also known as secondary storage devices or auxiliary devices.

19. Secondary Storage Devices • Removable • Floppy disk, or diskette • Compact Disc CD-R, CD-RW, CD-ROM • DVDs – DVD-ROM, DVD-R, DVD-RW, DVD-RAM • Zip disk • Flash disk/USB drive • Tape • Non-Removable • Hard disk

20. Primary Storage Devices • It is divided into two parts: . 1 Read Only Memory (ROM): This part of memory contains permanently stored information. When the power is switched off. ROM does not wash away. . 2 Random Access Memory (RAM):This part of memory consists of blank chips and hence the computer can use it to store and retrieve (write and read) information during its processing. The information stored in RAM is volatile, that is, when the computer is shut down the stored information is lost.

21. The central processing unit (CPU), also called the microprocessor, the processor or central processor is the brain of the computer. The CPU is housed on a tiny silicon chip. This chip contains millions of switches and pathways that help your computer make important decisions. The switches control the flow of the electricity as it travels across the miles of pathways. The CPU knows which switches to turn on and which to turn off because it receives its instructions from computer programs. The CPU has two primary sections: Control Unit Arithmetic/Logic Unit System Unit

22. Types of Computer Softwares SOFTWARE: - The software is the planned, step-by-step set of electronic instructions required to turn data into information that makes a computer useful. As stated software, or program, consists of the instructions that tell the computer how to perform a task. It is fall into two categories: - • System software. • Application software.

23. Types of Computer Softwares 1.System Software: - System software enables the application software to interact with the computer and helps the computer manage its internal and external resources. System software is required to run application software. Buyers of new computers will find the system software has already been installed by the manufacture. There are two basic types of system software such as: - Operating system. (e.g. Windows, DOS, etc) Utility programs: (e.g. Antivirus, file compression,etc)

24. Types of Computer Softwares 2. Application Software: Application software, also known as an application, is computer software designed to help the user to perform singular or multiple related specific tasks. Examples include accounting software, office suites, graphics software, and media players.

25. Application Software • Word Processing • Spreadsheet • Presentation Graphics • Database • Contact Management

26. Computers, file size, units of measurement The basic unit used in computer data storage is called a bit (binary digit). Computers use these little bits, which are composed of ones and zeros, to do things and talk to other computers. All your files, for instance, are kept in the computer as binary files and translated into words and pictures by the software (which is also ones and zeros).

27. UNITS OF MEMORY • 8Bit = 1Byte • 1024 Byte = 1 KiloByte • 1024 KiloByte = 1 Mega Byte • 1024 MegaByte = 1 GigaByte • 1024 Giga Byte = 1 Tera Byte • 1024 Tera Byte = 1 Pica Byte • 1024 Pica Byte = 1 Nano Byte

28. Electronic Commerce • When you conduct business activities online, you are participating in electronic commerce, also known as e-commerce • Business to consumer (B2C) involves the sale of goods to the general public • Consumer to consumer (C2C) involves one consumer selling directly to another • Business to business (B2B) provides goods and services to other businesses

29. Virus A program or piece of code that is loaded onto your computer without your knowledge and runs against your wishes. Viruses can also replicate themselves. All computer viruses are manmade. A simple virus that can make a copy of itself over and over again is relatively easy to produce. Some viruses are programmed specifically to damage the data on your computer by corrupting programs, deleting files, or even erasing your entire hard drive. Even such a simple virus is dangerous because it will quickly use all available memory and bring the system to a halt. An even more dangerous type of virus is one capable of transmitting itself across networks and bypassing security systems.

30. Antivirus Antivirus (or "anti-virus") software is a class of program that searches your hard drive and floppy disks for any known or potential viruses. In order to be an effective defense, your antivirus software needs to run in the background at all times, and should be kept updated so it recognizes new versions of hateful software.

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