1. Essential Computing Concepts Computer Department Foundation Program Fall 2009

2. 2 People: the most important part Hardware: consists of the equipment: keyboard, monitor, etc… Software: refers to the programs and its purpose is to convert data into information Data: unprocessed facts, and once processed, it becomes information. Procedures: guidelines for people to follow when using software, hardware, and data Information System An Information System has the following parts:

3. 3 What is a Computer System? HardwareSoftware Equipment Programs

4. 4 SupercomputerSupercomputer: The fastest and most expensive high-capacity computers used by very large organizations MainframeMainframe: Large computers, capable of great processing speeds and data storage Minicomputer: midrange computers used by medium-sized companies MicrocomputerMicrocomputer: Least powerful, small computers, but most widely used (desktop, Notebook or laptop, and Personal Digital Assistants) Types of Computers

5. 5 Supercomputer Mainframe

6. 6 Microcomputer Desktop Laptop PDA (Personal Digital Assistant)

7. 7 Supercomputer Mainframe Minicomputer Microcomputer More Less Powerful More Less Price

8. 8 Any Computer System Memory Central processing unit (CPU) Input Hard Disk Output

9. 9 Processing Cycle 2. Central processing unit (CPU) 3. Output 1. Input Memory 4. Storage

10. 10 Main Parts of a PC include: The System Unit  CPU  Memories ( Temporary or Permanent ) Input Devices Output Devices Secondary storage Devices Communication Devices

11. 11 The System Unit The Motherboard, RAM, ROM, Hard Drive, Video Card and Power Supply are all inside the System Unit. Ports and buses are used to connect Input, Output, Secondary Storage and Communication devices to the System Unit.

12. 12 Picture of a Motherboard Slots RAM CPU Ports

13. 13 The Motherboard Everything inside the system unit is connected to the motherboard. Cards are plugged into slots on the Motherboard Example: Graphics Card, Sound Card, Network Card. Hard drive is connected by cables.

14. 14 The CPU Central Processing Unit (or Processor) The brain of the computer Does all the Calculation and Processing Contains:  Control Unit (CU): translates instructions from: Users language to the machine’s language (0s and 1s). From machine’s language to users language.  Arithmetic Logic Unit (ALU): does the logical & arithmetic operations.

15. 15 The speed of the CPU Hertz CPU is Measured in Hertz  1 Hertz = 1 cycle/second  1 cycle = 1 addition Conversion table:  1 Kilohertz (KHz)=1000 Hz  1 Megahertz (MHz)= 1000 KHz=1,000,000 Hz  1 Gigahertz (GHz)= 1000 MHz=1,000,000,000 Hz Typical speed of modern CPU is 3 GHz.

16. 16 Random Access Memory (RAM) Electronic Components that temporarily store data (numbers, text, graphics, etc) being processed All programs and data are loaded into RAM Temporary/Volatile – is deleted when the computer is switched off Bytes Measured in Bytes.

17. 17 Read Only Memory (ROM) A set of chips containing permanent (non- changeable) instructions to make the computer start working. Can be read but cannot be written to

18. 18 Ports and Buses Located on the system unit Used to connect peripherals (any outside device you can attach to your computer) Types:  Serial Port  Parallel Port  Universal Serial Bus (USB)

19. 19 Serial Ports  data transferred bit by bit  Normally two: COM1 and COM2  Used to connect devices such as modems Parallel Ports  Transfer more than one bit in one read/write  Usually two: LPT1 and LPT2  Used to connect devices such as printers Universal Serial Bus (USB)  Serial – one bit in one read/write  Used for devices like scanners, digital cameras and flash drives

20. 20 Input Devices Mouse Keyboard Scanner Microphone video camera light pen joystick

21. 21 Output Devices Monitor/Screen Printers  Laser printers  Inkjet printers Plotters: To print maps, floor plans and big designs. Speakers

22. 22 Secondary Memory/Storage (Permanent) Magnetic Disk Hard/Fixed Disk (HD) Floppy Disk (FD) Optical Disk Compact Disk (CD) Digital Versatile Disk (DVD) Flash Memory formatted formattedDisks must be formatted before useformatted Format draws tracks on the disk Tracks is divided into sectors

23. 23 Formatting a disk Track Sector Preparing a disk for reading and writing Disks will be divided into tracks and sectors

24. 24 Magnetic Disks Floppy Disk  Most common is 1.44MB  Consists of thin, circular, flexible plastic disk with magnetic coating. Hard Disk  Consists of 1 or more rigid metal platters coated with a metal oxide material for recording.  Common size 10GB to 75GB.

25. 25 CD (Compact Disc) Flat, round, portable, metal storage. In variety formats:  CD-ROM (CD-Read Only Memory) Capacity: 650MB-800MB  CD-R (CD-Recordable) Write on disc one time only  CD-RW (CD-Rewritable) Write many times (similar to floppy)

26. 26 Same size as a CD but stores seven times CD capacity on a single side. DVDs can also be double-sided or dual layer. Today most DVDs are used to display full-length commercial motion pictures. Capacity: 4.7GB to 17GB DVD (Digital Video Disc)

27. 27 Flash Memory Also known as flash drive, pen drive, jump drive, thumb drive, key drive, or memory stick. Removable data storage device that uses flash memory (Electro- Magnetic memory) and a USB connector Attached via computer USB ports. Capacity up to 16GB(as in 2006).* *Inside the Flash Memory *Refer to: http://en.wikipedia.org/wiki/USB_flash_drive

28. 28 Storage Devices Capacities Storage DeviceCapacity Floppy Disk1.44 MB CD650-800 MB DVD4.7 to 17 GB FlashUp to 16 GB Hard Disk10GB to 75GB

29. 29 Peripherals Type of computer hardware that is added to a computer.computer hardwarecomputer Typical examples: Camera, Scanner, Joystick, Printers, Flash Memories. * From: http://en.wikipedia.org/wiki/Peripherals

30. 30 Computer = Hardware + Software Hardware : refers to the Equipment Software : refers to the Programs  A program is a set of instructions which tells the computer how to do its work Types of Software

31. 31 Types of Software System Software : Programs to control the operation of the computer  E.g. Operating System (Windows, Unix, Linux etc) Application Software : Programs for various applications  E.g. Programs for word processing, business, scientific and other applications such as Microsoft Office which consists of MS Word, MS Excel, etc.

32. 32 Machine’s Language All data entered to the computer must be represented by series of 0s and 1s (i.e. by Bits). A Bit (short for Binary digit) is the smallest unit of storage in the computer. It consists of two numbers 0 or 1. This representation is called: Binary System.

33. 33 Binary Numbering System Base 2 Consists of only two digits: 0 and 1 Data is represented in Bytes. One character requires 1 Byte for storage. 1 Byte = 8 Bits. Example: 1  00000001 0  00000000

34. 34 Storing Data Storage capacity: The amount of information that can be stored in a secondary storage device or in a memory. Storage Capacity is measured in Bytes and its Multiples: (B, KB, MB, GB)

35. 35 Representing Data The ASCII code (American Standard Code for Information Interchange) is used for letters and symbols. There are 256 character in the ASCII Coding. “A”  65 (01000001) “?”  63 (00111111) “£”  163 (10100011)

36. 36 Bits & Bytes Bit:  All computers work on a binary numbering system, i.e. they process data in one's or zero's. This 1 or 0 level of storage is called a bit. Byte:  A byte consists of eight bits. Kilobyte:  A kilobyte (KB) consists of 1024 bytes, approx 1,000 bytes. Megabyte:  A megabyte (MB) consists of 1024 kilobytes approx 1,000,000 bytes. Gigabyte:  A gigabyte (GB) consists of 1024 megabytes approx 1,000,000,000 bytes.

37. 37 Conversion from Binary to Decimal and from Decimal to Binary Binary to Decimal 1101 (binary) = 1*2 3 + 1*2 2 + 0*2 1 + 1*2 0 = 1*8 + 1*4 + 0*2 + 1*1 = 8 + 4 + 0 + 1 = 13 (decimal) Decimal to Binary 13(Decimal)=1101(binary) 13 2 6 1 2 3 0 2 1 1

38. 38 Exercise Convert 101 from binary to decimal. Convert 7 from decimal to binary.

39. 39 Storage Capacity Temporary Storage Random Access Memory (RAM) 256MB – 1GB Permanent Storage Floppy Disk 1.44 MB Hard Disk 40 – 120 GB CD (Compact Disk) about 700 MB DVD (Digital Versatile Disk) 8.5 GB

40. 40 Occupational Health & Safety Using the computer for long periods of time, may pose risk to health. Ergonomics: Position of the monitor – Frame above screen should be level with eyes, so that you look slightly down. Distance should be less than an arm’s length. Avoid screen reflection and flickering. Posture of the user – Chair back upright, lower back supported, feet flat on floor, Forearms should be horizontal, wrists straight and task materials within comfortable reach of both hands. Preventive exercises should be done before commencing work, during work and after lunch breaks. Eye exercises : Take frequent short rests: Look away from screen towards objects 20-30 ft away, or look outside the window far out, or close your eyes. Muscle exercises : Do neck exercises. After every hour walk around, stretch all muscles and perform whatever relieves the feeling of muscle fatigue/strain Suggested reading: www.healthycomputing.com/officewww.healthycomputing.com/office