concepts-of-computer.ppt abcccccccccccccccccccccc
- 2. 2 Hardware vs. Software ïŹ Hardware » The computer equipment » Includes printers, monitors, disk drives, etc. ïŹ Software » Programs which tell the computer what to do » Examples - word processing, gradebook, tutorials, games, etc.
- 3. 3
- 4. 4 History of Computers ïŹ Charles Babbage - father of computer » 1800âs planned analytical engine ïŹ ENIAC - developed at end of WW II ïŹ 1951 - 1963 1st and 2nd generation » very large, used unreliable vacuum tubes ïŹ 1963 - present - 3rd and 4th generation » smaller, faster - use transistors and integrated circuits
- 5. 5 History - Microcomputers ïŹ Apple » First sold in late 1970âs » Developed by Jobs and Wozniak ïŹ IBM Personal Computers » First sold in 1981 » Was quickly accepted by businesses » IBM compatibles soon developed
- 6. 6 Computer - Social Impact ïŹ Threat to privacy ïŹ Reduce personal interactions ïŹ Displace workers and change workplace » Create two tiered society ïŹ Computer failures cause great damage ïŹ Artificial Intelligence » Create a ânew life formâ » Machines smarter than their creators
- 7. 7 Types of Computers â Personal Computers (PC) ïŹ Also called Microcomputers ïŹ Available in desktop size, notebook size and handheld ïŹ Can be IBM, IBM Compatible or Apple
- 8. 8 Types of Computers - Minicomputers ïŹ Size of filing cabinet ïŹ Used by small and medium size companies and institutions ïŹ Operated by computer specialist ïŹ Terminals allow many people to use
- 9. 9 Types of Computers - Mainframes ïŹ Very powerful ïŹ Very fast ïŹ Used by large corporations and governmental agencies ïŹ Operated by computer specialist
- 10. 10 Types of Computers- Supercomputers ïŹ Most powerful ïŹ Fastest ïŹ Most expensive » Several million dollars each ïŹ Used only by » Governmental agencies » Large international corporations
- 11. 11 Computer Operations Input Processing Output External Storage
- 12. 12 Input Devices - Keyboard ïŹ Most commonly used input device ïŹ Ergonomic - fit natural hand placement ïŹ Special keys » Enter, Function, Ctrl, Alt, Num Lock, Esc
- 13. 13 Input Devices - Mouse ïŹ Controls cursor on screen ïŹ May be mechanical or optical ïŹ Most models have a âwheelâ for scrolling
- 14. 14 Input Devices - Other ïŹ Pointers (replaces mouse on notepads) » Track point, track ball, touch pad ïŹ Scanner ïŹ Digital camera ïŹ Touch screen ïŹ Voice
- 15. 15 Output Devices ïŹ Monitor ïŹ Printer ïŹ Disk Drive » Can also be input device ïŹ Modem » Can also be input device
- 16. 16 Monitors ïŹ Made up of tiny elements called pixels ïŹ Each row of pixels is called a scan line ïŹ Picture is displayed by an electronic beam lighting up certain pixels
- 17. 17 Monitors - Resolution ïŹ Resolution is how sharp and clear the picture is ïŹ How many scan lines on the screen â 640 x 480 is low resolution â 1600 x 1200 is high resolution
- 18. 18 Monitors - Dot Pitch ïŹ Measures the distance between pixels ïŹ Commonly seen on monitors advertised » .49 (not very good) » .28 (much better) » .26 or lower (excellent)
- 19. 19 Monitors - Sizes ïŹ Screen measured diagonally » May also measure actual viewing area ïŹ 14â or 15â on bargain systems ïŹ 17â has become the standard ïŹ 19 and 21â available but are more expensive.
- 20. 20 Monitors - LCD ïŹ Liquid Crystal Display ïŹ Similar to digital watch ïŹ Used for notebook computers » Should be an Active Matrix Screen ïŹ Also used in flat screen monitors » Much thinner than regular CRT monitor » More expensive than regular CRT monitor
- 21. 21 Monitors - Video Card ïŹ Processes info to send to monitor ïŹ Amount of video memory may speed up graphic intensive programs » 32 megs âgeneral purpose » 128 or more megs â graphic intensive use ïŹ AGP port can speed up graphics ïŹ 3D accelerator card improves graphics
- 22. 22 Monitor - Buying Hints ïŹ17â or larger ïŹ.28 dot pitch or better ïŹ32 or more megs of memory on video card
- 24. 24 Printers - Laser ïŹ Works similar to a copy machine » Color printers available but more expensive ïŹ Fast, quite, with excellent quality ïŹ More expensive to buy and operate ïŹ Some units scan, photocopy, and print
- 25. 25 Printers - Ink Jet ïŹ Squirts small jet of ink onto paper to form characters ïŹ Replaced dot matrix ïŹ Quiet ïŹ Does good job on color ïŹ Good quality and reliability
- 26. 26 Printers - Dot Matrix ïŹ Strikes pins against ribbon to print ïŹ Comes in 9 and 24 pin ïŹ Once very popular ïŹ Now replaced by ink jet and laser
- 27. 27 Printers - Speed ïŹ Measured in pages per minute (PPM) ïŹ Laser printers range from 20-45 ppm » Color printing is slower
- 28. 28 Printers - Quality of Print ïŹ One measure is dots per inch (DPI) » 300 dpi for general purpose uses » 600 dpi for higher quality » 1200 dpi for photo quality ïŹ May have different vertical and horizontal resolution » 600 x 300 ïŹ Other factors can affect quality
- 30. 30 How Information Is Stored ïŹ Memory consist of switches which can be either on or off - Off=0 On=1 ïŹ Each on/off switch is called a bit ïŹ Eight bits make up a byte ïŹ It takes one byte to store a character » Character can be letter, space, punctuation, etc. » ASCII code used
- 31. 31 Other Memory Terms ïŹ Byte is eight bits ïŹ Kilobyte (KB) is approx. 1,000 bytes ïŹ Megabyte (MB) is approx. 1million bytes ïŹ Gigabyte (GB) is approx. 1 billion bytes
- 32. 32 Central Processing Unit ïŹ Also called CPU, processor or microprocessor ïŹ Is the âbrainsâ of the computer ïŹ Performs all computer operations
- 33. 33 CPU - IBM COMPATIBLES ïŹ Many made by company called Intel ïŹ Also made by AMD
- 34. 34 Pentium class processors ïŹ Needed to run most current software ïŹ Intel â Celeron or Pentium IV ïŹ AMD
- 35. 35 CPU - Clock Speed ïŹ Number of âcyclesâ per second computer can operate ïŹ Measured in megahertz (MHz) ïŹ One MHz = 1 million cycles per second ïŹ One gigahertz(GHz)=1 billion cycles ïŹ Current speeds 2-4 GHz
- 36. 36 CPU - Misc. ïŹ Performance also affected by speed of data bus » 400-800 MHz on most current systems ïŹ Cache can increase speed » Stores data you will likely need next in an area that has faster access » Both memory cache and disk cache used » Should be 512 K or better
- 37. 37 CPU - Buying Hints ïŹ Minimum of Pentium IV or AMD Athlon ïŹ Minimum of 2 GHz clock speed ïŹ Minimum of 512K of cache
- 38. 38 Internal Memory - RAM ïŹ RAM - Random Access Memory » CPU can access any location as quickly as any other ïŹ Can not only read current info but also write new info ïŹ Very important in determining capabilities of the computer system ïŹ Computer should have at least 256 megs - 512 preferred (can add to later)
- 39. 39 Internal Memory - ROM ïŹ ROM - Read Only Memory » Can read info Stored in ROM » Can not write new info into ROM ïŹ Used for âinternal workingsâ of computer ïŹ Buyer is not very concerned with ROM
- 41. 41 Floppy Drives ïŹ Comes in 5 1/4â and 3 1/2â » All systems now only have 3 1/2â ïŹ HD - High density - comes on all current systems » 3 1/2â - 1.44 megs
- 42. 42 Hard Drives ïŹ Built into machine ïŹ Made up of stack of platters ïŹ Can store much more than floppy drives » 40 gigabytes should be minimum ïŹ Can access info much faster than floppy drive
- 43. 43 CD ROM ïŹ Same as music CDs ïŹ Are read only ïŹ Can store over 650 megs ïŹ All programs now only sold on CD ïŹ Make multimedia possible ïŹ Come in different speeds - 20x, - 50x
- 44. 44 DVD-ROM ïŹ Digital Video Disk ïŹ Can store up to 17 GB ïŹ Can store full-length movies ïŹ Can also read CD-ROM disk
- 45. 45 CD-RW & DVD-RW DRIVES ïŹ Allows you to write to disk ïŹ Useful for » Data backup » Storage of large files » Recording music and other multimedia files ïŹ DVD-RW » Allows you to write to both CD and DVD disk » Still somewhat expensive
- 46. 46 Storage Devices - Other ïŹ USB drive » Very popular â 64-512 MB ïŹ Tape drive » Similar to cassette tape » Used for backup ïŹ Zip drive » 100 MB to 2 GB capacity » Everyday use and backup
- 47. 47 Drives - Buying Advice ïŹ 40 gigabyte hard drive ïŹ One 3 1/2â high density floppy drive ïŹ CD-RW drive ïŹ DVD not yet essential but useful
- 48. 48 Expansion Slots ïŹ Allows you to add capabilities ïŹ Example of cards you can add » Network card » Modem
- 49. 49 Ports ïŹ Connects computer to another device ïŹ Parallel port » Used primarily by printers ïŹ Serial ports » Modem, mouse, etc. ïŹ SCSI - chain devices ïŹ USB âmay be needed for » Digital Cameras » Mp3 players » Other devices
- 50. 50 Networks ïŹ Connects computers ïŹ LAN - Local Area ïŹ WAN - Wide Area ïŹ Wireless ïŹ Allows sharing of programs, files, printers, etc. ïŹ Server is âmainâ computer
- 51. 51 Modems - General ïŹ Allows 2 computers to communicate over phone lines ïŹ Can be internal or external ïŹ Can also have fax capabilities
- 52. 52 Modems ïŹ Bits per second(bps) indicates speed » Old modems - 9,600, 14,400, 28,800, 33,600 » 56,000 (56K) has becoming standard ïŹ Ways of connecting to the Internet » Dial-up modem â used in most homes » Cable modem â uses TV cable lines » DSL â modified phone line » T1 line â used by schools, businesses, etc.
- 53. 53 Buying Hints Summary - Min Hardware Requirements ïŹ 2 GHz Pentium IV Class Processor ïŹ 256 megabytes of RAM ïŹ 17â, .28 dot pitch monitor with 32 meg card ïŹ 40 gigabyte hard drive ïŹ CD-RW ïŹ 56k modem ïŹ Ink jet or laser printer
- 54. 54 Buying Hints - Software Bundles ïŹ Many systems come with software included ïŹ Productivity » Microsoft Works » Microsoft Office, Lotus SmartSuite, etc » Quicken, Money, or other financial software ïŹ Reference » Microsoft Encarta or Comptonâs encyclopedia ïŹ Games
- 55. 55 Buying Hints - Service and Warranty ïŹ Toll-free 24 hr 7 day support (800 #) ïŹ 1 year warranty on parts and labor ïŹ Optional extended warranty ïŹ 30 day return policy
- 56. 56 Buying Hints - Web Sites ïŹ On-line computer stores » C-Net Hardware â reviews and prices from many vendors » Dell - http://www.dell.com/ » Gateway - http://www.gateway.com/
- 57. 57
- 58. 58 Programs ïŹ Set of instructions to the computer ïŹ Programming languages » Machine language » Assembly language » Procedural languages â Basic, Fortran, Cobol » Object oriented languages â Visual Basic, C++, C#, Java
- 59. 59 Systems Software ïŹ Run fundamental operations » Loading and running programs » Saving and retrieving data » Communicating with printers, modems, etc. ïŹ Examples of systems software » DOS » Windows 3.1, 95, 98, Me, 2000, and XP » Unix » Linux
- 60. 60 Applications Software ïŹ Helps you to accomplish a certain task ïŹ Examples » Word processing - memos, reports, etc. » Spreadsheets - budgets, etc. » Database - search, sort, select data » Educational - simulations, practice » Graphics - charts, diagrams » Desktop publishing - pamphlets, etc.
- 61. 61 Software - Legal Issues ïŹ Commercial software » Can only make backup copies for yourself » Can only use on one machine at a time â Site license - use on more that one machine ïŹ Shareware » Can use - make copies and give to anyone » Should pay if you continue to use ïŹ Freeware â can copy and use indefinitely
- 62. 62 Software Viruses ïŹ Illegal code added to a program ïŹ May spread to many computers » Copy files from one computer to another » Download files by modem » E-mail attachments ïŹ Virus may be relatively harmless » Writes âYouâve been stonedâ on screen ïŹ Virus may also be very damaging » Erases everything on hard drive ïŹ Virus may activate on a certain date
- 63. 63 Virus Protection ïŹ Be careful where you copy files from ïŹ Do not open e-mail attachments unless you are sure that it is safe ïŹ Use virus protection program » Detects and removes illegal code » Should be updated often
- 64. BASIC COMPUTER CONCEPTS End of Slide Show