2. Hardware Basics: Peripherals 3

3.  2001 Prentice Hall3.2 Chapter Outline Input: From Person to Processor Output: From Pulses to People Storage Devices: Input meets Output Computer Systems: The Sum of Its Parts “We swim in a sea of information.” Gary Snyder

4.  2001 Prentice Hall3.3 The Omnipresent Keyboard Keyboards are used to input and manipulate information with keys such as Letters and Numbers…

5.  2001 Prentice Hall3.4 The Omnipresent Keyboard …and Cursor Keys that allow you to move around the screen …Function Keys that send special commands…

6.  2001 Prentice Hall3.5 Reading Tools Optical-mark readers Bar-code readers Magnetic-ink character readers Wand readers Pen scanners

7.  2001 Prentice Hall3.6 Scanners Digitizing the Real World Audio digitizing and Speech recognition software Video digitizing Sensing devices

8.  2001 Prentice Hall3.7 Scanners Scanners capture and digitize images from external paper sources

9.  2001 Prentice Hall3.8 Video Digitizers Video digitizers contain circuitry to digitize frames from camcorders and other video sources.

10.  2001 Prentice Hall3.9 Digital Cameras Digital cameras turn real-world scenes into digital images that can be stored and manipulated by the computer The images, stored in memory, can be transferred to a computer for either editing or storage

11.  2001 Prentice Hall3.10 Audio Digitizers Audio digitizers contain circuitry to digitize sounds from microphones and other audio devices. Spoken words, music, and sound effects can be captured.

12.  2001 Prentice Hall3.11 Sound Video Monitor Controlling Other Machines Output: From Pulses to People Paper

13.  2001 Prentice Hall3.12 Screen Output Video Monitor –Also called Video Display Terminal (VDT) –Image exists in video memory—VRAM –Monitor size is measured diagonally across the screen

14.  2001 Prentice Hall3.13 Images are made up of dots called pixels for picture elements Pixels The number of pixels affects the resolution of the monitor The higher the resolution, the better the image quality

15.  2001 Prentice Hall3.14 Color Depth (Pixel Depth) The amount of information per pixel is known as the color depth –Monochrome (1 bit of information per pixel) –Gray-scale (8 bits of information per pixel) –Color (8 or 16 bits of information per pixel) –True color (24 or 32 bits of information per pixel)

16.  2001 Prentice Hall3.15 Examples of Color Depth 1-bit depth 16-bit depth 8-bit depth 4-bit depth

17.  2001 Prentice Hall3.16 CRT (cathode ray tube) LCD (liquid crystal display) Classes of Monitors

18.  2001 Prentice Hall3.17 A CRT is a television-style monitor featuring: CRT (Cathode Ray Tube) –Clear image –Quick response time –Low cost

19.  2001 Prentice Hall3.18 LCDs are flat-panel monitors Features include: –Lighter weight –More compact More expensive Dominate the portable computer market LCD (Liquid Crystal Display)

20.  2001 Prentice Hall3.19 Paper Output Paper output is sometimes called hard copy Hard copy can come from one of two kinds of printers: –Impact printers –Nonimpact printers

21.  2001 Prentice Hall3.20 Line printers –Used by mainframes for massive jobs –Limited characters available Impact Printers Dot-matrix printers –Image formed from dots printed on paper –Good for text and graphics –Inexpensive

22.  2001 Prentice Hall3.21 Nonimpact Printers Laser printers –Image transferred to paper with laser beam –Faster and more expensive than dot-matrix –High-resolution hard copy

23.  2001 Prentice Hall3.22 Other Nonimpact Printers Ink-jet –Dots of ink are sprayed onto the paper to form the image –High-resolution hard copy –Some models print can print color photographs

24.  2001 Prentice Hall3.23 Rules of Thumb: Ergonomics and Health Choose equipment that’s ergonomically designed Create a healthy workspace Build flexibility into your work environment Rest your eyes Stretch tight muscles

25.  2001 Prentice Hall3.24 Output You Can Hear Synthesizers can be used to generate music and sounds Many computers have synthesizers Sound cards have built-in synthesizers

26.  2001 Prentice Hall3.25 Output devices turn bit patterns into non- digital movements Controlling Other Machines — Robot arms — Telephone switchboards — Transportation devices — Automated factory equipment — Spacecraft

27.  2001 Prentice Hall3.26 Storage Devices: Input Meets Output Peripherals with both input and output functions provide semi- permanent storage for data Examples include: –Magnetic tape and disks –Zip, Jaz and SuperDisks –Magneto-optical disks

28.  2001 Prentice Hall3.27 Optical Disks Optical disks use laser beams rather than magnets to read and write information CD-RW drives can write, erase, and rewrite CDs CD-ROM drives are optical drives that read CD-ROMs DVD’s can hold between 3.8 and 17 gigabytes of data, they are replacing CD- ROMs

29.  2001 Prentice Hall3.28 Alternatives Flash memory –Compact alternative –No moving parts –May eventually replace disk and tape storage

30.  2001 Prentice Hall3.29 Ports and Slots…again The system board (motherboard) includes several ports: –Serial Port for attaching devices that send/receive messages one bit at a time (modems) –Parallel Port for attaching devices that send/receive bits in groups (printers) –Keyboard/Mouse Port

31.  2001 Prentice Hall3.30 Ports and Slots…again Other ports that are generally included on expansion boards instead of the system board: –Video Port used to plug in a color monitor into the video board –Microphone, speaker, headphone, MIDI ports used to attach sound equipment –SCSI port allows several peripherals to be strung together and attached to a single port

32.  2001 Prentice Hall3.31 Internal and External Drives Hard drive CD or DVD Floppy disk Zip Drive SCSI port

33.  2001 Prentice Hall3.32 Expansion Made Easy USB and Firewire ports allow multiple devices to be connected to the same port and to be hot swapped: –USB (Universal Serial Bus) transmits a hundred times faster than a PC serial port –Firewire (IEEE 1394) can move data between devices at 400 or more megabits per second

34.  2001 Prentice Hall3.33 Putting It All Together: Networks Networks blur the boundaries between computers –Networks can include hundreds of different computers –Can span the globe by using satellites and fiber optic cables