What is Computer ?

1. What is Computer ? • A Powerful Electronic Device • Accept user-supplied data and instruction • Store them, perform mathematical operations • Output the results according to user specifications • Transfer data, images and sound through telephone lines or cables at very fast rate Prepared By BHIM SAPKOTA

2. Normally We Found The Full Form Of Computer Is: - C = Commonly O = Operated M = Machine P = Particularly U = Used for T = Trade E = Education and R = Research Prepared By BHIM SAPKOTA

3. Basic Computer System Processor Input Output Memory Prepared By BHIM SAPKOTA

4. Speed Storage Accuracy Diligence:-Never Fatigue . Versatility Communication Characteristics of a computer Prepared By BHIM SAPKOTA

5. Computer Software and Hardware • Software • Set of instructions that is required to get the Hardware to perform works • Programs • Hardware • Physical components comprising different types of electronic circuits • Accessible physically Hardware +Software +Data =Solution Prepared By BHIM SAPKOTA

6. Software • A computer without software is similar to a Television without Programs and Channels. • Software is a large collection of several • Sets of instructions called computer • programs. • Computer programscan be small, • consisting of 10 lines of instructions, • or extremely large having a few • thousand lines of complex code. • These programs can be made to • work by giving commands. Prepared By BHIM SAPKOTA

7. Users / People Users provide the input to the computer. Users make use of the outputs generated by the computer Prepared By BHIM SAPKOTA

8. System Software General Purpose Software Programming Languages Application Software Categories of Software Prepared By BHIM SAPKOTA

9. Controls & Supports Computer System Also known as Operating Systems Systems Software Prepared By BHIM SAPKOTA

10. Components of Computer • Central Processing Unit (CPU) • Memory • Input Devices • Output Devices Prepared By BHIM SAPKOTA

11. Central Processing Unit Memory Unit Arithmetic & Logic Unit Control Unit Hardware – Central Processing Unit Prepared By BHIM SAPKOTA

12. Central Processing Unit • Brain of Computer • Comprises two distinct parts • Arithmetic and logic Unit • Control Unit • Microprocessor Prepared By BHIM SAPKOTA

13. Memory • Primary Storage • Read-Only Memory (ROM) • Permanence • Security • ROM • PROM • EPROM • EEPROM • Random Access Memory (RAM) • Dynamic RAM (DRAM) • Static RAM (SRAM) Prepared By BHIM SAPKOTA

14. Secondary Storage • Floppy Disk Drives • Hard Disk Drives • Optical Disk Drives • Magnetic Tape Drives Prepared By BHIM SAPKOTA

15. P O S T Power On Self Test Computer Start up - • Executes a number of instructions to check the • CPU performance • Checks that the ROM is not corrupted • or damaged • Writes to and reads from every memory • location available in RAM • Uses the input and output device drivers to check for and initialize all available I/O devices including keyboard, video, sound and disk drives Prepared By BHIM SAPKOTA

16. Hardware – Input Devices Input Devices Keyboard Mouse Scanner Trackball Microphone Digital Camera Prepared By BHIM SAPKOTA

17. Hardware – Output Devices Output Devices Monitor Printer LCD Speakers Display Adapters Prepared By BHIM SAPKOTA

18. Analog Digital Hybrid IBM Compatible Apple Computers All Computers have CPU, Secondary Storage and I/O Devices Midrange or Mini computers PCs or Microcomputer Laptops/Notebooks Supercomputers / Mainframes Classification of Computer (On basis of Compatibility) (On basis of Model) (On basis of Size and Power) Prepared By BHIM SAPKOTA

19. Types of Computer on the basic of Model:- Analog Computer:- Analog computer represents the number by a physical quantity I.E. They assign Numeric values by physically measuring same actual properties, such as the length of an object and angle created by two lines. Eg : Multi Miter, Speedo Meter, Analog Watch. Digital Computer:- They represent data as number or separates units the digit computer can accurately represent the data using as many position and numbers as necessary, Like Calculator. Eg: Digital Watch, Calculators. Prepared By BHIM SAPKOTA

20. Hybrid commuter:- Hybrid Computer combines the best feathers of analog and digital computers. They have the Speed of Analog computers and Accuracy of Digital Computers. ON The Basic of BrandIBM- Compatible: - There are The computer designed According to the IBM Standards. • Apple Computer:- Those are the Macintosh Computer. Branded Computer. Prepared By BHIM SAPKOTA

21. Classification Of Computer on the Basic of Size and Power 1.Super/Mainframes Computer:- Super Computer is the largest, fastest, most-Powerful and most expensive computer made like other large system. It can be Accessed By many individual at the same Time. • only 200 super computer in USA • Used Since 1950s • Large computers with excellent processing power and big memory size • Serve 100s of users at a time • Required customized software and trained professionals to maintain • Special air-conditioning required • Application-Commercial Prepared By BHIM SAPKOTA

22. Midrange/Mini Computer:- Introduced in 1970’s. Powerful Multi-user system but comparatively slower then Mainframe Or Super Computer. Process 10 million instructions per second. PC/Micro/Notebook/Laptop Computer:- Portable Computing come of age with the creation of notebook computer .Portable computers that are small enough to fit into a average sized briefcase. Battery operated. Advantages in hardware technology made it compact. Minimum cost and unlimited application. Easy to maintain and support. Prepared By BHIM SAPKOTA

23. Different Generations Of Computers • First Generation (1951-1958) • EDSAC (Electronic Delay Storage Automatic Calculator) • Second Generation (1959-1964) • IBM 1401 • Third Generation (1965-1971) • IBM 360 • Fourth Generation (1971-Present) Prepared By BHIM SAPKOTA