1. Understanding Computers, 12 th Edition, Enhanced Chapter 4 1 Input and Output

2. Understanding Computers, 12 th Edition, Enhanced 2 Overview This chapter covers: Keyboards and pointing devices Scanners and related devices Biometric and multimedia input devices Various types of display devices Various types of printers Multimedia output devices

3. Understanding Computers, 12 th Edition, Enhanced 3 Input and Output Input devices convert data from the user into a form understood by the computer. Output devices convert the processed 0s and 1s into a form that the user can understand. Hard copy—permanently recorded, such as on paper. Soft copy—temporarily recorded, such as on a computer screen.

4. Understanding Computers, 12 th Edition, Enhanced 4 Keyboards Computers usually use a keyboard for text-based input. Keyboards can differ in number of keys, key arrangement, types of special keys, and touch. Function keys enable software packages to be customized to meet a user's applications needs. The numeric keypad makes it easy to enter numbers quickly.

6. Understanding Computers, 12 th Edition, Enhanced 6 Keyboards, Cont’d. Portable keyboards and thumb pads are increasingly being used with portable PCs and mobile devices.

7. Understanding Computers, 12 th Edition, Enhanced 7 Pointing Devices Mice The mouse is the most common type of pointing device. Can be mechanical or optical. Used to select onscreen objects, issue commands, move objects, scroll through documents, etc.

9. Understanding Computers, 12 th Edition, Enhanced 9 Pointing Devices, Cont’d. Electronic pens (light pen, stylus) An alternative to the mouse to select objects or to write or draw on the screen. Commonly used with: Graphics tablets Digital portfolios and digital pens Signature capture devices Pen-based computers Handwriting recognition technology

11. Understanding Computers, 12 th Edition, Enhanced 11 Pointing Devices, Cont’d. Touch screens Used when other input devices are impractical. Often used when consumer input is required, as in consumer kiosks.

12. Understanding Computers, 12 th Edition, Enhanced 12 Pointing Devices, Cont’d. Other common pointing devices Joysticks and other gaming devices Trackballs Pointing sticks Touch pads

13. Understanding Computers, 12 th Edition, Enhanced 13 Scanners and Related Devices Source data automation involves converting source documents to digital form or initially collecting data in digital form. Often involves scanning or reading devices.

14. Understanding Computers, 12 th Edition, Enhanced 14 Scanners Scanners (optical scanners) convert hard-copy images of text pages, photographs, and drawings into digital form. Types of scanners: Flatbed Sheet-fed Handheld Drum Three-dimensional Quality of scanned images are measured by resolution.

16. Understanding Computers, 12 th Edition, Enhanced 16 Optical Mark Readers (OMRs) Read optical marks, such as on: Exams Census forms Voting ballots Lottery forms

17. Understanding Computers, 12 th Edition, Enhanced 17 Bar-Code Readers Bar code—an optical code consisting of several bars of varying widths that form a unique, identifiable code. Read by fixed or portable bar-code readers. Common types: Universal Product Code (UPC) POSTNET code Proprietary codes for shippers, hospitals, and other businesses

18. Understanding Computers, 12 th Edition, Enhanced 18 Optical Character Recognition (OCR) Devices Optical characters are designed to be identifiable by humans as well as OCR device. Widely used in turnaround documents, such as monthly bills.

19. Understanding Computers, 12 th Edition, Enhanced 19 Magnetic Ink Character Recognition (MICR) Readers MICR readers can read the special magnetic characters and sort and process documents accordingly. Used primarily for processing checks.

20. Understanding Computers, 12 th Edition, Enhanced 20 Biometric Input Devices Used to input biometric data about a person. Biometric data is based on unique physical characteristics (e.g. fingerprint) or personal traits (e.g. voice). Used for access and to verify transactions. Biometric readers can be stand-alone or built into keyboards or other hardware devices.

21. Understanding Computers, 12 th Edition, Enhanced 21 Multimedia Input Devices Digital cameras record data onto digital media instead of conventional film or tape. Images can be transferred to a PC via a cable or the storage media (such as a flash memory card with a digital still camera). Can be digital still cameras or digital video cameras.

22. Understanding Computers, 12 th Edition, Enhanced 22 Multimedia Input Devices, Cont’d. Digital still cameras Images are usually stored on flash memory cards. Photos can usually be immediately previewed and deleted, if needed. Photos are easily transferred to a PC to be stored and/or printed. Camera quality is measured in mexapixels. Digital photos can be printed at home or at a photo lab.

24. Understanding Computers, 12 th Edition, Enhanced 24 Multimedia Input Devices, Cont’d. Digital video cameras Store images on digital media (typically digital tape or optical discs). Video can be easily transferred to a PC for editing and/or burning onto a DVD. Can be used for videoconferencing and Web cams.

25. Understanding Computers, 12 th Edition, Enhanced 25 Multimedia Input Devices, Cont’d. Audio input devices Voice-input systems convert spoken words to digital data. Voice input can be used to input data or commands into a PC as well as for telephony. Music-input systems can input and record music (either original compositions or via a CD or DVD player).

26. Understanding Computers, 12 th Edition, Enhanced 26 Display Devices Display device characteristics Color vs. monochrome displays Size (measured diagonally) Screen resolution Graphic standards

27. Understanding Computers, 12 th Edition, Enhanced 27 Display Devices, Cont’d. CRT (cathode-ray tube) monitors —display images similar to conventional televisions. Quality is measured in dot pitch.

28. Understanding Computers, 12 th Edition, Enhanced 28 Display Devices, Cont’d. Flat-panel displays—form images by manipulating electronically-charged chemicals or gases between thin panes or glass or plastic. Common types: Liquid crystal displays (LCD) Gas plasma Used for monitors, televisions, handheld devices, and other consumer products.

29. Understanding Computers, 12 th Edition, Enhanced 29

30. Understanding Computers, 12 th Edition, Enhanced 30 Display Devices, Cont’d. Smart displays HDTV monitors Data projectors Emerging display technologies and applications (e.g. flexible displays, e-paper, integrated displays, etc.)

31. Understanding Computers, 12 th Edition, Enhanced 31 Printers Printer characteristics Printer resolution—measured in dots per inch (dpi) Impact vs. non-impact printing Color vs. black and white Personal vs. network printers Speed

32. Understanding Computers, 12 th Edition, Enhanced 32 Laser Printers The standard for business documents. Work similarly to photocopy machines; print with toner powder. Are usually black and white, though color laser printers are available. Fast print speed; print one page at a time.

33. Understanding Computers, 12 th Edition, Enhanced 33 Ink-Jet Printers Print with tiny drops of liquid ink. Typically print in color. Often the choice for home use. Print fairly slowly, one line at a time. Quality not quite as good as a laser printer.

34. Understanding Computers, 12 th Edition, Enhanced 34 Special Purpose Printers Photo printers Bar-code printers Label printers Portable printers Plotters and wide-format ink-jet printers Fax machines Multifunction devices 3D Printers

36. Understanding Computers, 12 th Edition, Enhanced 36 Multimedia Output Devices Speakers Voice-output systems- sometimes called text-to-speech systems Headphones and Headset