BASIC COMPUTER CONCEPTS Updated 8 27 04 2 Hardware

BASIC COMPUTER CONCEPTS Updated 8/27/04

2 Hardware vs. Software l Hardware » The computer equipment » Includes printers, monitors, disk drives, etc. l Software » Programs which tell the computer what to do » Examples - word processing, gradebook, tutorials, games, etc.

4 History of Computers l Charles Babbage - father of computer » 1800’s planned analytical engine ENIAC - developed at end of WW II l 1951 - 1963 1 st and 2 nd generation l » very large, used unreliable vacuum tubes l 1963 - present - 3 rd and 4 th generation » smaller, faster - use transistors and integrated circuits

5 History - Microcomputers l Apple » First sold in late 1970’s » Developed by Jobs and Wozniak l IBM Personal Computers » First sold in 1981 » Was quickly accepted by businesses » IBM compatibles soon developed

6 Computer - Social Impact Threat to privacy l Reduce personal interactions l Displace workers and change workplace l » Create two tiered society Computer failures cause great damage l Artificial Intelligence l » Create a “new life form” » Machines smarter than their creators

Types of Computers – Personal Computers (PC) l l l Also called Microcomputers Available in desktop size, notebook size and handheld Can be IBM, IBM Compatible or Apple 7

Types of Computers Minicomputers l Size of filing cabinet l Used by small and medium size companies and institutions l Operated by computer specialist l Terminals allow many people to use 8

Types of Computers Mainframes l Very powerful l Very fast l Used by large corporations and governmental agencies l Operated by computer specialist 9

Types of Computers. Supercomputers Most powerful l Fastest l Most expensive l » Several million dollars each l Used only by » Governmental agencies » Large international corporations 10

11 Computer Operations Input Processing External Storage Output

12 Input Devices - Keyboard l Most commonly used input device l Ergonomic - fit natural hand placement l Special keys » Enter, Function, Ctrl, Alt, Num Lock, Esc

13 Input Devices - Mouse l Controls cursor on screen l May be mechanical or optical l Most models have a “wheel” for scrolling

14 Input Devices - Other l Pointers (replaces mouse on notepads) » Track point, track ball, touch pad l Scanner l Digital camera l Touch screen l Voice

15 Output Devices l Monitor l Printer l Disk Drive » Can also be input device l Modem » Can also be input device

16 Monitors l l l Made up of tiny elements called pixels Each row of pixels is called a scan line Picture is displayed by an electronic beam lighting up certain pixels

17 Monitors - Resolution l Resolution is how sharp and clear the picture is l How many scan lines on the screen – 640 x 480 is low resolution – 1600 x 1200 is high resolution

18 Monitors - Dot Pitch l Measures the distance between pixels l Commonly seen on monitors advertised » . 49 (not very good) » . 28 (much better) » . 26 or lower (excellent)

19 Monitors - Sizes l Screen measured diagonally » May also measure actual viewing area l 14” or 15” on bargain systems l 17” has become the standard l 19 and 21” available but are more expensive.

20 Monitors - LCD Liquid Crystal Display l Similar to digital watch l Used for notebook computers l » Should be an Active Matrix Screen l Also used in flat screen monitors » Much thinner than regular CRT monitor » More expensive than regular CRT monitor

21 Monitors - Video Card Processes info to send to monitor l Amount of video memory may speed up graphic intensive programs l » 32 megs –general purpose » 128 or more megs – graphic intensive use AGP port can speed up graphics l 3 D accelerator card improves graphics l

22 Monitor - Buying Hints l 17” or larger l. 28 dot pitch or better l 32 or more megs of memory on video card

23 Printers l Laser l Ink Jet l Dot Matrix

24 Printers - Laser l Works similar to a copy machine » Color printers available but more expensive l Fast, quite, with excellent quality l More expensive to buy and operate l Some units scan, photocopy, and print

25 Printers - Ink Jet l Squirts small jet of ink onto paper to form characters l Replaced dot matrix l Quiet l Does good job on color l Good quality and reliability

26 Printers - Dot Matrix l Strikes pins against ribbon to print l Comes in 9 and 24 pin l Once very popular l Now replaced by ink jet and laser

27 Printers - Speed l Measured in pages per minute (PPM) l Laser printers range from 20 -45 ppm » Color printing is slower

28 Printers - Quality of Print l One measure is dots per inch (DPI) » 300 dpi for general purpose uses » 600 dpi for higher quality » 1200 dpi for photo quality l May have different vertical and horizontal resolution » 600 x 300 l Other factors can affect quality

29 Basic Processing Cycle Central Data Bus Processing Unit Internal Memory

30 How Information Is Stored Memory consist of switches which can be either on or off - Off=0 On=1 l Each on/off switch is called a bit l Eight bits make up a byte l It takes one byte to store a character l » Character can be letter, space, punctuation, etc. » ASCII code used

31 Other Memory Terms l Byte is eight bits l Kilobyte (KB) is approx. 1, 000 bytes l Megabyte (MB) is approx. 1 million bytes l Gigabyte (GB) is approx. 1 billion bytes

32 Central Processing Unit l Also called CPU, processor or microprocessor l Is the “brains” of the computer l Performs all computer operations

33 CPU - IBM COMPATIBLES l Many made by company called Intel l Also made by AMD

34 Pentium class processors l Needed to run most current software l Intel – Celeron or Pentium IV l AMD

35 CPU - Clock Speed Number of “cycles” per second computer can operate l Measured in megahertz (MHz) l One MHz = 1 million cycles per second l One gigahertz(GHz)=1 billion cycles l Current speeds 2 -4 GHz l

36 CPU - Misc. l Performance also affected by speed of data bus » 400 -800 MHz on most current systems l 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 CPU - Buying Hints l Minimum of Pentium IV or AMD Athlon l Minimum of 2 GHz clock speed l Minimum of 512 K of cache

38 Internal Memory - RAM l RAM - Random Access Memory » CPU can access any location as quickly as any other l l l Can not only read current info but also write new info Very important in determining capabilities of the computer system Computer should have at least 256 megs 512 preferred (can add to later)

39 Internal Memory - ROM l ROM - Read Only Memory » Can read info Stored in ROM » Can not write new info into ROM l Used for “internal workings” of computer l Buyer is not very concerned with ROM

40 External Memory

41 Floppy Drives l Comes in 5 1/4” and 3 1/2” » All systems now only have 3 1/2” l HD - High density - comes on all current systems » 3 1/2” - 1. 44 megs

42 Hard Drives l Built into machine l Made up of stack of platters l Can store much more than floppy drives » 40 gigabytes should be minimum l Can access info much faster than floppy drive

43 CD ROM Same as music CDs l Are read only l Can store over 650 megs l All programs now only sold on CD l Make multimedia possible l Come in different speeds - 20 x, - 50 x l

44 DVD-ROM l Digital Video Disk l Can store up to 17 GB l Can store full-length movies l Can also read CD-ROM disk

45 CD-RW & DVD-RW DRIVES l l Allows you to write to disk Useful for » Data backup » Storage of large files » Recording music and other multimedia files l DVD-RW » Allows you to write to both CD and DVD disk » Still somewhat expensive

46 Storage Devices - Other l USB drive » Very popular – 64 -512 MB l Tape drive » Similar to cassette tape » Used for backup l Zip drive » 100 MB to 2 GB capacity » Everyday use and backup

47 Drives - Buying Advice l 40 gigabyte hard drive l One 3 1/2” high density floppy drive l CD-RW drive l DVD not yet essential but useful

48 Expansion Slots l Allows you to add capabilities l Example of cards you can add » Network card » Modem

49 Ports l Connects computer to another device l Parallel port » Used primarily by printers l Serial ports » Modem, mouse, etc. l SCSI - chain devices l USB –may be needed for » Digital Cameras » Mp 3 players » Other devices

50 Networks l l l Connects computers LAN - Local Area WAN - Wide Area Wireless Allows sharing of programs, files, printers, etc. Server is “main” computer

51 Modems - General Allows 2 computers to communicate over phone lines l Can be internal or external l Can also have fax capabilities l

52 Modems l Bits per second(bps) indicates speed » Old modems - 9, 600, 14, 400, 28, 800, 33, 600 » 56, 000 (56 K) has becoming standard l Ways of connecting to the Internet » » Dial-up modem – used in most homes Cable modem – uses TV cable lines DSL – modified phone line T 1 line – used by schools, businesses, etc.

Buying Hints Summary - Min Hardware Requirements l l l l 2 GHz Pentium IV Class Processor 256 megabytes of RAM 17”, . 28 dot pitch monitor with 32 meg card 40 gigabyte hard drive CD-RW 56 k modem Ink jet or laser printer 53

Buying Hints - Software Bundles l l Many systems come with software included Productivity » Microsoft Works » Microsoft Office, Lotus Smart. Suite, etc » Quicken, Money, or other financial software Reference » Microsoft Encarta or Compton’s encyclopedia Games 54

Buying Hints - Service and Warranty l Toll-free 24 hr 7 day support (800 #) l 1 year warranty on parts and labor l Optional extended warranty l 30 day return policy 55

56 Buying Hints - Web Sites l On-line computer stores » C-Net Hardware – reviews and prices from many vendors » Dell - http: //www. dell. com/ » Gateway - http: //www. gateway. com/

58 Programs l Set of instructions to the computer l Programming languages » Machine language » Assembly language » Procedural languages – Basic, Fortran, Cobol » Object oriented languages – Visual Basic, C++, C#, Java

59 Systems Software l Run fundamental operations » Loading and running programs » Saving and retrieving data » Communicating with printers, modems, etc. l Examples of systems software » » DOS Windows 3. 1, 95, 98, Me, 2000, and XP Unix Linux

60 Applications Software l Helps you to accomplish a certain task l 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 Software - Legal Issues l Commercial software » Can only make backup copies for yourself » Can only use on one machine at a time – Site license - use on more that one machine l Shareware » Can use - make copies and give to anyone » Should pay if you continue to use l Freeware – can copy and use indefinitely

62 Software Viruses l l Illegal code added to a program May spread to many computers » Copy files from one computer to another » Download files by modem » E-mail attachments l Virus may be relatively harmless » Writes “You’ve been stoned” on screen l Virus may also be very damaging » Erases everything on hard drive l Virus may activate on a certain date

63 Virus Protection Be careful where you copy files from l Do not open e-mail attachments unless you are sure that it is safe l l Use virus protection program » Detects and removes illegal code » Should be updated often

64 BASIC COMPUTER CONCEPTS End of Slide Show