C OMPUTING E SSENTIALS Presentations by: Fred Bounds Timothy J. O’Leary Linda I. O’Leary

4 4 Input and Output CHAPTER

3 Computing Essentials Chapter Four Competencies After reading this chapter, you should be able to: 1. Explain the difference between keyboards and direct-entry input devices. 2. Describe the features of keyboards and the four types of terminals. 3. Describe direct-entry devices used with microcomputers.

4 Computing Essentials Chapter Four Competencies 4. Discuss voice recognition systems. 5. Describe monitors and monitor standards. 6. Describe printers (ink-jet, laser, thermal) and plotters (pen, ink-jet, electrostatic and direct-image) 7. Describe voice-output devices.

5 Computing Essentials Chapter Four Overview Two most important places for computer- human interface Computers can only work with binary language Input devices translate what we understand to a form acceptable to the computer Output devices do the reverse

Input: Keyboard versus Direct Entry Input devices convert people-readable data into machine-readable form. Input may be by keyboard or direct entry.

7 Computing Essentials Chapter Four Data Entry Keyboard entry –Keys like typewriter to enter text and numbers –Data normally comes from an original or source document Direct entry –Data in machine readable form at entry point

8 Computing Essentials Chapter Four Data Entry Entry methods –Point-of-sale (POS) methods - keyboard and bar scanning –Wand reader –Platform scanner A Point-of-sale transaction

Keyboard Entry In keyboard entry, people type input. There are four types of terminals: dumb, intelligent, network computer and Internet terminal.

10 Computing Essentials Chapter Four Traditional keyboard Escape key Navigation keys Function keys SpacebarSpacebar Numeric keypad Windows key

11 Computing Essentials Chapter Four Keyboard Entry Keyboards - besides alphanumeric, special purpose keys that toggle or work with the Control, Alt and Shift keys

12 Computing Essentials Chapter Four Keyboard Entry Terminals - input and output device connecting users to mainframe computers –Dumb terminal - no processor or local storage –Intelligent terminal - CPU, memory and storage; Net PC, or network computer

13 Computing Essentials Chapter Four Keyboard Entry Terminals - input and output device connecting users to mainframe computers –Network terminal - low cost alternative to intelligent terminal –Internet terminal - or Web terminal, accesses and displays Web pages on a television set

Direct Entry Direct entry creates machine- readable data that can go directly to the CPU. Direct entry includes pointing, scanning and voice-input devices.

15 Computing Essentials Chapter Four Direct Entry Data is already in machine-readable format No keyboard or transcription device required Three categories –Pointing devices –Scanning devices –Voice-input devices

16 Computing Essentials Chapter Four Pointing Devices Mouse, trackball or touch- surface - cursor moves in response to rolling ball or moving finger Traditional keyboard Left button Right button Roller ball Retaining ring CableCable

17 Computing Essentials Chapter Four Pointing Devices Mouse, trackball or touch- surface - cursor moves in response to rolling ball or moving finger Touch screen - screen recognizes position of touching finger

18 Computing Essentials Chapter Four Pointing Devices Mouse, trackball or touch- surface - cursor moves in response to rolling ball or moving finger Touch screen - screen recognizes position of touching finger Light pen - screen recognizes position of light- sensitive pen-like device

19 Computing Essentials Chapter Four Pointing Devices Digitizer - special pad and stylus used to capture images hand drawn Digital camera - image recorded digitally and stored on chips or disks; not yet film quality, but increasingly popular as prices drop Digital notebook - notepad that can capture handwriting and store it

20 Computing Essentials Chapter Four Digitizer: an industrial design

21 Computing Essentials Chapter Four Pen-based computer: recording inventory

22 Computing Essentials Chapter Four Scanning Devices Image scanner - images scanned and broken into digital code Fax machine - scanner codes images and sends them over the phone line Bar-code readers - photoelectric scanner reads vertical bars

23 Computing Essentials Chapter Four Image Scanner Identifies images on a page and converts them to digital electronic signals Increased usage in desktop publishing and for home use as well

24 Computing Essentials Chapter Four Fax Machines Fax machine - scans images and transmits them over phone lines to a receiving fax on the other end Fax modem cards in computers achieve same results without scanning capability

25 Computing Essentials Chapter Four Bar-Code Readers Photoelectric scanners that read vertical zebra- striped marks called bar codes The bar code is a unique identifier that links to a product code in the store’s computer

26 Computing Essentials Chapter Four Bar-Code Readers The computer contains the product description and price

27 Computing Essentials Chapter Four Scanning Devices Character and mark recognition devices –Magnetic-ink character recognition (MICR) - used by banks to read magnetically encoded characters –Optical-character recognition (OCR) - specially preprinted characters are read by OCR devices such as wand scanners –Optical-mark recognition (OMR) - devices sense the presence or absence of marks, common for test scoring

28 Computing Essentials Chapter Four Voice-Input Devices Convert speech into digital code Most common device is the microphone Voice recognition systems –Microphone, bundled with sound card and software –Some voice recognition systems must be trained for user’s voice –Some can translate from one language to another

29 Computing Essentials Chapter Four Voice Recognition Systems Continuous speech - used to issue commands to special application programs Discrete-word - permits users to dictate directly into a microcomputer

Output: Monitors, Printers, Plotters, Voice Output devices convert machine- readable information into people- readable form.

Monitors Monitor standards indicate screen quality. Some monitors are used on the desktop, others are portable.

32 Computing Essentials Chapter Four Monitor Standards VGA (“Video Graphics Array”) - 16 colors at 640 by 480 Super VGA or SVGA (“Super Video Graphics Array”) - minimum resolution of 800 by 600, up to 1600 by 1200 XGA (“Extended Graphic Array”) - resolution up 1024 by 768, over 18 million colors

33 Computing Essentials Chapter Four Cables Serial mouse, modem, keyboard Video monitor

34 Computing Essentials Chapter Four Color and Resolution Capabilities VGA 640 X XGA1024 X ,536

35 Computing Essentials Chapter Four Monitors Cathode-Ray Tubes - similar to television technology Flat-Panel Monitors - or liquid display (LCD) monitors –Passive-matrix or dual-scan - images created by scanning the entire screen –Active-matrix - each pixel is individually activated

36 Computing Essentials Chapter Four A desktop monitor: SVGA display

Printers There are three types of printers: ink-jet, laser and thermal.

38 Computing Essentials Chapter Four Printers Ink-jet Printer –Sprays droplets of ink on paper to produce text and images –Inexpensive

39 Computing Essentials Chapter Four Printers Laser Printer –Technology similar to photocopier –Laser beam creates images which are applied via toner to paper

40 Computing Essentials Chapter Four Printers Thermal Printer –Heat used to produce text and images on heat-sensitive paper –Very high quality color option

41 Computing Essentials Chapter Four Printers Other Printers –Dot-matrix uses pins to produce dots on paper to represent text and images –Chain printer - high speed printer for minicomputers and mainframes

Plotters Plotters are special-purpose drawing devices.

43 Computing Essentials Chapter Four Plotters Pen Plotter –Moving pen or pencil over drafting paper –Least expensive –Slower speed and limited capability Ink-Jet Plotter –Uses sprayed droplets of ink –Faster

44 Computing Essentials Chapter Four Plotters Ink-Jet Plotter –Uses sprayed droplets of ink –Faster –High quality –Quiet operation

45 Computing Essentials Chapter Four Plotters Electrostatic Plotter –Electrostatic charges (rather than pens) produce dots on specially treated paper –Paper is then developed –Very fast –Hazardous chemicals

46 Computing Essentials Chapter Four Plotters Direct Imaging Plotter –Electrically heated pins create images on heat-sensitive paper –Expensive paper required –Two-color output only

Voice-Output Devices Voice-output devices vocalize prerecorded sounds.

48 Computing Essentials Chapter Four Voice-Output Devices Make sounds that resemble human speech but actually are using prerecorded vocalized sounds Components are often a sound card and a speaker system

49 Computing Essentials Chapter Four