1. 1 Course Title: IT IN BUSINESS Course Instructor: ADEEL ANJUM Chapter No: 04 1 BY ADEEL ANJUM (MCS, CCNA,WEB DEVELOPER)

2. 2 Chapter NoChapter NamePage No 1.INTRODUCTION TO IT01 2. INPUT & OUT PUT DEVICES251 3.SOFTWARE117 4.HARDWARE117 5.COMMUNICATIONS & NETWORKS309 6.INTERNET49 2 Course Contents BY ADEEL ANJUM (MCS, CCNA,WEB DEVELOPER)

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4. 4 MEASURING CAPACITY BIT In binary number system each 0 or 1 is called bit which is short for binary digit. BYTE A group of 8 bit is called byte and a byte represents one character,digit,or other value. The capacity of a computer’s memory is expressed in number of bytes.

5. 5 KILOBYTE A kilobytes (KB) is about 1024 bytes. MEGABYTE A megabyte is about 1 million bytes or 1024 kilobytes. GIGABYTE A gigabyte is 1 billion or bytes or 1024 megabytes TERABYTE A terabyte represent 1 trillion bytes 0r 1024 gigabytes

6. 6 1.POWER SUPPLY The power supply is a device that converts AC voltage to DC voltage to run the computer.AC voltage can burn out the low voltage DC circuitry in your computer.

7. 7 POWER SUPPLY

8. 8 2.UPS A UPS (Un-interruptible power supply) is a battery that provides a computer with electricity if there is a power failure. The UPS will keep a computer going for 5-30 minutes or more. power supply unit is joule.0ne 100 joule of energy keep a 100 watt light giving for 1 second.

9. 9 3.BUSES Buses are electrical data road ways through which bits are transmitted within cpu and between the cpu and other components of the motherboard.

10. 10 4.PORTS A Port is a connecting socket into which cables of different kind are plugged. it allows you to connect peripheral devices such as monitor,keyboard, mouse,printer,scanner, modem etc. we have different types of ports like serial port, parallel ports etc.

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12. 12 5.MOTHERBOARD it is main circuit board in the system unit. it contain non removable components, slots for components that can be removed. like microprocessor,RAM,Various cards etc.

13. 13 motherboard

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15. 15 6.CPU The brain of computer is CPU.CPU stands for central processing unit. it control different devices. All calculations are made inside the cpu. PARTS OF CPU 1.control unit 2.ALU arithmetic logic unit

16. 16 1. ALU The arithmetic/logic unit performs arithmetic operations and logical operations. and controls the speed of these operation. arithmetic operation are addition,subtraction,multiplication,and division. logical operations are comparisons, like greater than >,equal than ==, less than < less than or equal than etc.

17. 17 2.CONTROL UNIT It controls the movement of electrical signals between main memory and the ALU.It also directs these signal between main memory and input and out put devices.

18. 18 cpu

19. 19 FUNCTIONS OF CPU Performs all arithmetic and logical operation in the arithmetic and logical unit ALU sends the result to output devices control the activities of other units.

20. 20 7.STORAGE DEVICE TEMPORARY STORAGE DEVICE 1. RAM 2. CACHE MEMORY 3. REGISTERS

21. 21  PERMANENT STORAGE DEVICES 1. ROM (read only memory) 2. CMOS( complementary metal oxide semiconductor) 3. FLOPPY DISK 4. HARD DISK 5. OPTICAL DISK 6. MAGNETIC TAPE 7. FLASH MEMORY

22. 22 1.RAM RAM (random access memory) or Primary or main memory, temporarily hold data before it is processed by the cpu. when you open file a copy of file is transfer from hard disk to RAM. when you save file it is transferred from RAM to hard disk. RAM is said to be volatile, the contents are lost when the power is goes off or it is turned off.

23. 23 RAM

24. 24 Types Of RAM 1. DRAM (Dynamic RAM) 2. SDRAM (Synchronous dynamic RAM) 3. SRAM (Static RAM) 4. DDR-SDRAM (Double data rate synchronous dynamic RAM.)

25. 25 2.CACHE MEMORY As cpu runs much faster than main memory.cpu wait for instructions so to reduce this wait we use cache. Cache is temporary memory. It store instructions for short time. It speed up processing. There are three type of cache. 1. Level 1 cache 2. Level 2 cache 3. Level 3 cache

26. 26 cache Level 1 It is part of processor also called internal cache. its size is 256 kb.  Level 2 it is out side processor not part of processor it is also called external cache. its size is 2 MB.  Level 3 it is on motherboard near ram.

27. 27 3.REGISTER Register are high speed storage areas that temporarily store data during processing. for example,if two numbers are multiplied both number must be in register and result is also placed in register.

28. 28 1.ROM ROM read only memory cannot be written on or erased by the computer user without special equipment.ROM chips contain fixed start up instruction. the contents of ROM are permanent.

29. 29 2.CMOS MEMORY complementary metal oxide semiconductor chips are power by a battery and thus do not lose their contents, when the power is turned off. CMOS Chips contain instruction such as time,date,calender.unlike ROM chip CMOS chip can be reprogrammed as when you need to change. your system software allow you to change time and date stored on CMOS.

30. 30 3.VIRTUAL MEMORY virtual memory is some free space on hard disk, it is used to extend RAM. The processor searches for data in this order first in level 1 cache then L2 cache then L3 cache then main memory then virtual memory. then hard disk.

31. 31 4.FLOPPY DISK It is removable flat plastic case which store data permanently. it store about 1.45 mega byte data. Super disk can store 120 megabyte.

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33. 33 5.HARD DISK Hard disk provide a very big storage capacity and are very fast. it store data permanently. it consist of metal platter fixed on vertical spindle. platter is coated with magnetic material on which data is recorded

34. 34 6.OPTICAL DISK An optical disk is removable disk which store data permanently. To read data laser light is used. Pitted area are not reflected and are interpreted as 0 bits smooth area are reflected and are interpreted as 1 bits. Example: CDs (compact disks) DVDs (digital versatile disk)

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36. 36 7.FLASH Flash is non volatile memory. it holds up to 4 gigabyte of data. example USB universal serial bus, also called flash drive or keychain drive.

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