Download to read offline
Uploaded bySyed Iftikhar Ali Shah
Introduction to Computer
The document discusses the impact of computers on society and various organizations. It notes that computers are used in nearly every aspect of modern life, including homes, education, business, industry, government, and healthcare. Computers provide important information to users and help manage large amounts of data. The document also describes different types of computers used in organizations like servers, mainframes, minicomputers, and supercomputers. It explains how these computers are suited to different needs based on the number of users and tasks.
More Related Content
Introduction to Computer
- 1. Copyright © 2006by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education McGraw-Hill Technology Education Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.
- 2. 1A-2 Computers In Society •More impact than any other invention – Changed work and leisure activities – Used by all demographic groups • Computers are important because: – Provide information to users – Information is critical to our society – Managing information is difficult
- 3. 1A-3 Computers In Society •Computers at home – Many homes have multiple computers – Most American homes have Internet – Computers are used for • Business • Entertainment • Communication • Education
- 4. 1A-4 Computers In Society •Computers in education – Computer literacy required at all levels • Computers in small business – Makes businesses more profitable – Allows owners to manage • Computers in industry – Computers are used to design products – Assembly lines are automated
- 5. 1A-5 Computers In Society •Computers in government – Necessary to track data for population • Police officers • Tax calculation and collection – Governments were the first computer users
- 6. 1A-6 Computers In Society •Computers in health care – Revolutionized health care – New treatments possible – Scheduling of patients has improved – Delivery of medicine is safer
- 7. 1A-7 Computers For Organizations •Network servers – Centralized computer – All other computers connect – Provides access to network resources – Multiple servers are called server farms – Often simply a powerful desktop
- 8. 1A-8 Computers For Organizations •Mainframes – Used in large organizations – Where many people frequently use the samed data – Handle thousands of users – Users access through a terminal – Dumb and Intelligent terminal – Less flexible,only specific task – Air line flight,Vehicle records,Insurance and Bank
- 9. 1A-9 Computers For Organizations •Minicomputers – Called midrange computers – Power between mainframe and desktop – Handle hundreds of users – Used in smaller organizations – Users access through a terminal
- 10. 1A-10 Computers For Organizations •Supercomputers – The most powerful computers made – Handle large and complex calculations – Process trillions of operations per second – Hold thousands of processors – Found in research organizations – Weather forcasting
- 11. 4A-11 Monitors • Most commonoutput device • Connects to the video card • Categorized by color output – Monochrome • One color with black background – Grayscale • Varying degrees of gray – Color • Display 4 to 16 million colors
- 12. Monitors • Cathode RayTube (CRT) – Most common type of monitor – Electrons fired from the back – Electrons excite phosphor to glow – Phosphor is arranged in dots called pixels – Dot mask ensures proper pixel is lit
- 13. Monitors • CRT color –Phosphor dots arranged in triads – Red, green, and blue dots – Three colors blend to make colors – Varying the intensity creates new colors
- 14. Monitors • CRT drawbacks –Very large – Very heavy – Use a lot of electricity
- 15. Monitors • Liquid CrystalDisplay (LCD) – Commonly found on laptops – Desktop versions exist – Solve the problems of CRT – Fluorescent lights provide illumination
- 16. Monitors • Passive matrixLCD – Pixels arranged in a grid – Pixels are activated indirectly • Row and column are activated – Animation can be blurry
- 17. Monitors • Active matrixLCD – Each pixel is activated directly – Pixels have 4 transistors • One each for red, green, blue • One for opaqueness – Transistors arranged in a thin film – Animation is crisp and clean
- 18. Monitors • Drawbacks toLCD – More expensive than CRT – Must sit directly in front of screen – Can be more fragile than CRT
- 19. Monitors and VideoCards • Monitors impacts user effectiveness • Monitors should have – Crisp text – Clear graphics – Adjustable controls – Clear edges
- 20. Monitors and VideoCards • Size of monitor – Measured in inches – Measured diagonally – Actual size • Distance from corner to corner – Viewable size • Useable portion of the screen
- 21. Monitors and VideoCards • Resolution – Number of pixels on the screen – Higher number creates sharper images – Higher number creates smaller images – 640*480 means pixels on the screen
- 22. Monitors and VideoCards • Refresh rate – Number of time the screen is redrawn or pixels refreshed – Modern equipment sets this automatically – Improper settings can cause eyestrain – Look for printers having RR greater than 72 Hz
- 23. Monitors and VideoCards • Dot pitch – Distance between the same color dots – Ranges between .15 mm and .40 mm – Smaller creates a finer picture – Should be less than .22
- 24. Video Cards • Devicebetween the CPU and monitor • Better cards result in better output • Removes burden of drawing from CPU • Have their own processor and RAM • Modern cards have up to 512 MB RAM • Capable of rendering 3D images
- 25. Ergonomics and Monitors •Eyestrain – Fatigue of the eyes – Steps to avoid • Choose a good monitor • Place the monitor 2 – 3 feet away • Center of screen below eye level • Avoid reflected light
- 26. Ergonomics and Monitors •Electronic magnetic fields (EMF) – Generated by all electronic devices – EMF may be detrimental to health – Steps to avoid • Keep the computer at arms length • Take frequent breaks • Use an LCD monitor
- 27. Data Projectors • Replacedoverhead and slide projectors • Project image onto wall or screen • LCD projectors – Most common type of projector – Small LCD screen – Very bright light – Require a darkened room
- 28. Data Projectors • DigitalLight Projectors – A series of mirrors control the display – May be used in a lighted room
- 29. Sound Systems • Integralpart of the computer experience • Capable of recording and playback
- 30. Sound Systems • Soundcard – Device between the CPU and speakers – Converts digital sounds to analog – Can be connected to several devices – Modern cards support Dolby Surround Sound
- 31. Sound Systems • Headphonesand headsets – Replacement for speakers and microphones – Offer privacy – Does not annoy other people – Outside noise is not a factor – Headsets have speakers and a microphone
- 32. Copyright © 2006by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education Chapter 4B Printing
- 33. 4B-33 Commonly Used Printers •Impact printers – Generate output by striking the paper – Uses an inked ribbon • Non-impact printers – Use methods other than force – Tend to be quiet and fast
- 34. 4B-34 Commonly Used Printers •Dot matrix printers – Impact printer – Used to print to multi-sheet pages – Print head strikes inked ribbon – Line printers – Band printers – Speed measured in characters per second
- 35.
- 36. 4B-36 Commonly Used Printers •Ink-jet printers – Non-impact printer – Inexpensive home printer – Color output common using CMYK • Cyan, magenta, yellow, black – Sprays ink onto paper – Speed measured in pages per minute – Quality expressed as dots per inch
- 37.
- 38. 4B-38 Commonly Used Printers •Laser printer – Non-impact printer – Produces high quality documents – Color or black and white – Print process • Laser draws text on page • Toner sticks to text • Toner melted to page – Speed measured in pages per minute – Quality expressed as dots per inch
- 39. 4B-39 Commonly Used Printers •All-in-one peripherals – Scanner, copier, printer and fax – Popular in home offices – Prices are very reasonable
- 40. 4B-40 Comparing Printers • Determinewhat you need • Determine what you can spend • Initial cost • Cost of operating (toner and cartridge mainenance) • Image quality (most medium inkjets can print 300 to 600 dpi.If printer resolution is 600 means 600*600=3600 dpi) • Speed (most consumer level laser printer can print 6-8 ppm and professional can print 50 ppm)
- 41. 4B-41 High-Quality Printers • Specialpurpose printers – Used by a print shop – Output is professional grade – Prints to a variety of surfaces
- 42. 4B-42 High-Quality Printers • Thermalwax printers – Produces bold color output – Color generated by melting wax – Colors do not bleed – Operation costs are low – Output is slow – For posters or Book covers
- 43. 4B-43 High-Quality Printers • Dyesublimation printers – Produces realistic output – Very high quality – Color is produced by evaporating ink – Operation costs are high – Output is very slow – For Desktop publishers and graphic artists
- 44. 4B-44 High-Quality Printers • Photoprinters – Produces film quality pictures – Prints very slow – Prints a variety of sizes
- 45. 4B-45 High-Quality Printers • Plotters –Large high quality blueprints – Older models draw with pens – Operational costs are low – Output is very slow
- 46. Copyright © 2006by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education Chapter 4B End of Chapter
Editor's Notes
- #4 Insider information The 2000 Census determined that 51% of American households had computers. Over 42% of these households also had Internet access. This can be contrasted to 36% and 18% in 1997. See www.census.gov/prod/2001pubs/p23-207.pdf for more information.
- #5 Insider information Specialized mountain bikes are designed on Sun workstations.
- #6 Teaching tip Most state departments of motor vehicles rely on a mainframe computer. Officers access the mainframe from a remote intelligent terminal.
- #7 Discussion point Page 19 of the text introduces the first Norton Notebook, the Merging of Media and Meaning. The author draws an analogy between electricity and computers in our lives. Discuss with your students how difficult live would be without either of these devices. Remember that computers exist in nearly all of our modern devices, including cars, phones, kitchen appliances and entertainment devices.
- #11 Teaching tip Students have a hard time understanding trillions of calculations. A simple explanation is to add 1 trillion random numbers together in a second. Contrast the speed of a super computer to the fastest desktop computer advertised during the week of class.
- #14 Teaching tip Unless your students have spend a lot of time with HTML or graphics colors, they will have a hard time grasping how RGB values work. The best methods are to show them various colors and then let them experiment. The website www.lynda.com/hue.html provides decimal-value examples of RGB values. Once the students have seen different colors, open MS Paint and let the students develop their own colors. Challenge them to build pink, orange, brown and any of their favorite colors
- #19 Insider information The limited viewing angle can be an advantage. For high security systems, low viewing angles stop casual glances at the screen.
- #21 Teaching tip It is helpful to draw the relationship between viewable and actual size.
- #22 Insider information Many CRT’s are capable of supporting several resolutions. LCD monitors in contrast often can only support one or two resolutions. The reason are the transistors on the LCD cannot move, while the electron gun on the CRT can simply aim for a smaller pixel. If you are in a computer class, stop and have students adjust their resolution on the screen. The simplest method is to right click the desktop and select properties. Click the settings tab, and adjust the slider. As the students are experimenting, have a student answer why larger resolution numbers make smaller images. The answer is higher resolutions draw with smaller pixels.
- #23 Insider information Whenever a TV camera films a computer monitor, the monitor seems to have a line moving up the screen. This is the monitor refreshing the pixels. The camera films faster than the eye can see, which is why the refresh is noticeable.
- #25 Insider information The two leading video card families are ATI’s Radeon and NVIDIA’s GeForce line. Both offer exceptional graphics cards ranging from $50 to $600.
- #27 Teaching tip Point out to the students that no conclusive study exists that directly list EMF as a cause of cancer, reduced muscle tone or reduced brain function. For more information see http://www.hhs.gov/ and search for EMF.
- #29 Insider information A projector is rated in lumens. This is a measure of how bright the projector is. Higher lumens ratings result in a brighter projector. For a guide to lumens ratings, see http://www.projectorpeople.com/tutorials/lumen-guide.asp.
- #31 Insider Information Sound Blaster is the primary manufacturer of sound cards. Exceptional models start at around $30.00.
- #32 Insider information The PS2 game SOCOM II Navy Seals includes a USB headset to allow verbal communication with other team members.
- #35 Teaching Tip Figure 4B.5 on page 163 provides an excellent rendering of how the print head works. Be sure to refer to the image as you teach.
- #37 Insider information Nearly all of the electronics for the printer is kept in the ink cartridge. Thus, when the cartridge is replaced the printing components of the printer are replaced. Refilling cartridges is OK, but should not be reused more than 2-3 times.
- #39 Insider information The laser printer works on a similar process to a photocopier. The first photocopier as we know it today was invented in Astoria NY in 1938 by Chester Carlson and Otto Kornei.