1. Section1 General Concepts

2. What is a computer? A computer is a machine that processes data or information according to a step by step sequence of instructions A computer can do a variety of different tasks at a time. It is multitasking Can store data (storage) Can execute a sequence of instructions.

3. Advantage of Computers : 1. Speed 2. Accurate 3. Save Data 4. Save Time 5. Network

4. Data and information Data is raw facts collected for processing Information : is the processed facts Data Information Processing

5. Types of computer According to their Size : 1.Supercomputers. 2. Mainframe Computer. 3. Minicomputers. 4. Microcomputers.

6. 1. Supercomputers : the most powerful type, special high capacity machine used for large organization

7. 2.Mainframe Computer : occupy specially wired, air condition room not powerful as super computer but it is capable of great processing speed and data storage ex: insurance companies.

8. 3.Minicomputers : also referred to as midrange or server less powerful than mainframe but more powerful than microcomputers, it used in large companies to support processing needs, retrieving data from databases

9. 4.Microcomputers : least powerful but most widely used, fastest growing type of computer.

10. Types of Microcomputer 1. Desktop Computer (Personal Computer PC) 2. Notebook or laptop 3. Netbook 4. Tablet PC 5. Handheld (PDA) 10

11. Desktop Computers It is Small enough to Fit on the top of analog side the desk, yet too big to carry 11

12. Notebook or laptop computers 12 Notebook computers also known as laptop computers, are portable and lightweight and fit into most briefcase

13. Netbook Similar to Notebook computers but smaller, lighter and less expensive 13

14. Tablet PC 14 The newest type of computer, they are smaller, lighter, less powerful than notebook have flat touchscreen and virtual keyboard ex : Apple Ipad

15. Handheld (PDA) Handheld (PDA) PDA ( Portable Digital Assistant) :Smallest type of computers, designed to fit in the one hand, some of combine pen input and writing recognition like smartphones 15

16. Computer Components Computer Components 1.Hardware : Physical component, a part you can see and touch  2. Software : The “programs” which a set of information that tell the computer what to do and how to do it 16

17. What is hardware? Physical component, a part you can see and touch  A hardware components : 1. input device 2. output device 3. central processing Unit (CPU) 4. storage device

18. What is a peripheral device? Hardware connected to computer to extend or improve its functionality.example: printer, scanner, flash drives, DVD,camera, speakers, microphones

19. 1. The Input Units Input Units : are the units which translate the data from users to processing units Any machine that feeds data into a computer.datacomputer Some hardware input devices include Barcode Keyboard Joystick Mouse Digital CameraScanner

20. Keyboard : is board containing the keys of letters, numbers and some function joystick: A joystick is an input device commonly used to control video gamesinput Scanner : is an electronic device that generates a digital representation of an image for data input to a computer Bar Code Reader : photoelectric scanner that translate the bar code symbols into digital form

21. Digital Camera : Images recorded digitally on disk or in camera’s memory Web Cam: Specialized digital video cameras built-in or attached to the monitor Microphone: Used to enter and record voices to the computer

22. Mouse : a small device, which you move across the top of the desk to move the pointer or cursor on the screen, can use rolling ball or laser Trackball: A trackball is an input device used to enter motion data into computers or other electronic devices. It serves the same purpose as a mouse, but is designed with a moveable ball on the top, which can be rolled in any direction. Instead of moving the whole deviceinput devicemouse.

23. Touchpad: A touch pad is a device for pointing (controlling input positioning) on a computer display screen. It is an alternative to the mouse. Originally incorporated in laptop computers, touch pads are also being made for use with desktop computers. A touch pad works by sensing the user's finger movement and downward pressure.mouselaptop computers computer stylus/pens: an input device used to write text or draw lines on a surface as input to a computer.computer

24. 2.The Output Units Output units : are the units which translate the processing units to users Monitor Printer Speakers

25. Monitor : like T.V screen used to show pictures and texts Speakers : it convert the voice analog to heard by the user

26. Printer : used to make a paper copy of the information into the computer. Plotter: A graphics printer that draws images with ink pens. It actually draws point-to-point lines directly from vector graphics files.

27. Output DevicesInput Devices 1.Computer monitor 2.Flat screen 3.Projector 4.Speakers and headphones 5.Printers 1.Keyboard 2.Mouse 3.Scanners 4.Joysticks 5.Web cams 6.Digital cameras 7.Microphones

28. Devices used for input and output processes Touch screen Fax Machine Modem

29. 3. CPU Central Process Unit (CPU): consider Brain of the computer It contain two units : 1. Arithmetic-Logic Unit (ALU) : it performs the mathematical and logical operations 2. Control Unit (CU ) : it directs the electronic signals between memory and arithmetic logic unit Some computers can have several CPUs running in parallel (EX: Mainframe computers )

30. 3. Memory Units ROMRAM Read Only Memory - Information stored by the manufacturer - Non-volatile and cannot be changed - CPU can read, data and programs in ROM but the computer cannot change ROM Random Access Memory - Hold programs and data that are currently being accessed - Data and programs stored in RAM are volatile (the information is lost when you switch off the computer)

31. A computer storage device is any type of hardware that stores data. 4.Storage devices: A computer storage device is any type of hardware that stores data. Drive typeCapacitySpeed Hard driveHigh, big storage, hundreds (100) of gigabytes Faster than CD, DVD, or floppy DVD drive Capacity of 4 gigabytes Slower than a hard disk drive CD drive650 megabytes Slower than a hard disk drive Floppy driveVery low storage capacity Slower than a hard disk drive

32. 1.Hard disc drive: The hard disk drive is the main, and usually largest, data storage device in a computer. The operating system, software titles and most other files are stored in the hard disk drive.operating system 2. Floppy disk: is a hardware device that reads data storage information. first types of hardware storage that could read/write a portable device. FDDs are used for reading and writing on removable floppy discs. Floppy disks are now outdated, and have been replaced by other storage devices such as USB.

33. 3.USB flash drive: a small external flash drive that can be used with any computer that has a USB port. 4.Zip Drives: Can be described as a kind of improved version of a floppy disk. Zip drives have more data storage capacity than traditional floppy drives (100-750) megabytes.

34. 5.Data Cartridges and Tape Drives: Tape drives are mechanisms that are in many ways like a traditional tape recorder or video cassette recorder. Used in companies and universities for backup and archive data for a long period

35. Measuring Memory : Size Data Measurement Single Binary Digit (1 or 0)Bit 8 bitsByte 1,024 BytesKilobyte (KB) 1,024 KilobytesMegabyte (MB) 1,024 MegabytesGigabyte (GB) 1,024 GigabytesTerabyte (TB)

36. Power supply and Fans Computers require Direct Current (DC) DC power provided by converting Alternating Current (AC) from wall outlets or batteries Desktop computers use Power Supply Units Notebooks and handhelds use AC Adapters

37. Hardware Port Port is used to connect the computer with a peripheral devices (input or output devices)

38. Common Ports : Port NameUsageImage LPT ( Parallel Port) used to connect printers and scanners Serial Port used to connect external modem and mouse USB Port used to connect a wide variety of devices like camera, flash driver, mice, keyboard,printer and more PS/2 Port connect mouse or keyboard video port connect a computer screen ( monitor) Fire wire Port connect digital video camera and external hard drive Ethernet (Network Port) connect Network Cables into this port

39. The Computer performance Factors 1.Speed 2.Storage CPU Clock Speed : (Processing speed )  The number of times the CPU fetches and processes data or instructions in a second.  The clock speed is given in Hertz (Hz).  1 MHz means that the device will run at one million cycles per second, ( 1 MHz = 1000000 Hz)  1 GHz is a thousand million times, so that ( 1 GHz = 1000000000 Hz).  The more memory you have the faster the PC will appear to operate.  Other factors Bus Speed, cache memory, CPU cache capacity, hard disk rotation speed, video card also affects on the computer performance