Basics of computer
- 1. Dr B T Sampath Kumar Professor Department of Library and Information Science Tumkur University, Tumakuru, INDIA www.sampathkumar.info Basics of Computer
- 2. What is Computer? • Computer is an electronic device that accepts the data (input), processes data, produces output, and stores (storage) the results. • It is an electronic device which – Accepts the data – Stores the data – Does arithmetic/Logical operations and – Gives the output in a neat desired format.
- 3. Components • The major components of a computer are: –Input unit –Output unit –System unit
- 4. Input Output Main Memory ALU CU Sec. Memory CPU CPU: Central Processing Unit CU: Control Unit ALU: Arithmetic & Logic Unit System Unit Components
- 5. Input unit • Data and instructions must be entered in to the computer system before any computation can be performed on the supplied data. • The input unit is used to feed the instructions/data to the system unit. • Keyboard, mouse, scanner, microphone are some of the examples for input devices.
- 6. Output unit • The job of an output unit is just the reverse of that of an input unit. • It supplies information and results of computation to the outside world. • Thus it links the computer with the external environment. • Printer, speaker, monitor are some of the examples for output devices.
- 7. System unit • The system unit has two parts: –Central Processing Unit (CPU) –Memory Unit (MU)
- 8. Central Procession Unit (CPU) • The Control Unit and the Arithmetic and Logic unit of a computer system are jointly known as the Central Processing Unit (CPU). • The CPU is the brain of any computer system. • All major calculations and comparisons are made inside the CPU. • CPU is also responsible for activating and controlling the operations of other units of a computer system.
- 9. Arithmetic and Logic Unit (ALU) • The Arithmetic and Logic Unit of a computer system is the place where the actual execution of the instructions take place during the processing operations. • All calculations are performed and all comparisons (decisions) are made in the ALU.
- 10. Control Unit (CU) • The control unit directs and controls the activities of the internal and external devices. • It interprets the instructions fetched into the computer. • It determines what data are needed, where it is stored, where to store the results of the operation. • It also sends the control signals to the devices which involved in the execution of the instructions.
- 11. Memory Unit (MU) • The data and instructions that are entered into the computer system through input units are stored in memory unit. • Similarly, the results produced by the computer after processing must also be kept in memory unit. • Memory unit provides space for storing data and instructions. • It also provides space for intermediate results and space for the final results.
- 12. Cont.. • Computer memory is of two basic types: – Primary memory (RAM and ROM) – Secondary memory (Hard disc, CD, DVD, Pen drive etc.).
- 13. Cont.. • Primary memory – Random Access Memory (RAM) is primary- volatile memory. – Read Only Memory (ROM) is primary-non- volatile memory. • Secondary memory – Secondary memory is used to store the data permanently. – Hard disc, CD, DVD and Pen drive are some of the examples for secondary storage devices.
- 14. Characteristics of computer The characteristics of computer are: Speed • Computer can work very fast. • It takes only few seconds for calculations. • It can perform millions of instructions and even more per second.
- 15. Cont.. Accuracy • The degree of accuracy of computer is very high. • Every calculation is performed with the same accuracy.
- 16. Cont.. Diligence • Computer is free from tiredness, lack of concentration, fatigue, etc. • It can work for hours without creating any error(s). • If millions of calculations are to be performed, a computer will perform every calculation with the same accuracy. • Due to this capability, it overpowers human being in routine type of works.
- 17. Cont.. Versatility • It means, the capacity to perform completely different type of works. • Computer can be used in: – Banks – Libraries – Hospitals – Retails shops – Educational institutes etc.,
- 18. Cont.. Storage • Computer has an in-built memory where it can store a large amount of data. • The data can be stored in various secondary storage devices such as: – Hard disc – CD – DVD – Pen drive – Memory cards etc.,