Input devices take in user commands and data, output devices engage our senses to present information, and storage holds data for future use. Common input devices include keyboards, mice, microphones, and digital cameras. Output is presented on displays and printers, while various storage technologies like hard disks, optical disks, solid-state drives, and tape hold data over time. Emerging technologies may allow new forms of input, output, and storage in the future.

1. Input/Output and Storage
Input Devices: Giving Commands
Output Device: Engaging our Senses
Storage: Holding data for Future use

2. Digital Cameras
•Digital cameras: Record images on digital storage medium rather than film
–Can either be still cameras or video cameras
–Typically use flash memory for storage
–Images can be edited, posted to a Web page, burned to a CD or DVD disc,
etc.
•Digital still cameras
–Available in a wide variety of sizes and capabilities
–Photos can be transferred to a PC or printer
–Camera quality is measured in megapixels
•Digital video cameras
–Digital camcorders
–PC video cameras (PC cams, Web cam)

4. Audio Input
•Audio input: The process of entering audio data into the computer
–Voice (narrations, podcasts, etc.)
–Music (from CDs, MIDI keyboards, etc.)
•Voice input systems (speech recognition systems)
–Enable a computer to recognize the human voice
–Consistof a microphoneorheadsetand appropriatesoftware
–Can be used to dictate text or commands into a PC

5. Voice Input Systems

6. Display Devices
•Display device: Presents output visually
–Monitor: Display device for a desktop PC
–Display screen: Screen built into a variety of devices
•Notebook and handheld PCs,
•Mobile phones and mobile devices
•E‐books readers, digital photo frames, and other consumer devices, and
many other devices
•Digital signage systems
•E‐paper

7. Display Device Characteristics
•Color vs. monochrome displays
•CRT vs. flat‐panel display
•Size
•Screen resolution
•Wired vs. wireless
•2D vs. 3D
•Digital TV and HDTV capabilities
•Touch screen capabilities

8. Screen Resolution

9. Flat‐Panel Display Technologies
• Liquid crystal displays (LCDs):
-Use charged liquid crystals between sheets of glass or plasticRequires
backlighting
• LED (Light emitting diode): Used in displays as well as a variety of
consumer products

10. Data and Multimedia Projectors
•Data projector: Display device that projects all computer output to a wall or
projection screen
–Most data projectors today can project video, in addition to computer
output
–Can be wireless or integrated into devices
–FogScreen systems projects on a thin layer of fog
–Holographic projectors are in development

11. Printers
•Printers: Produce hard copy
•Printer Characteristics
–Printing technology used
•Impact vs. nonimpact
–Color vs. black and white
–Personal vs. network printers
–Print resolution
–Print speed
–Possible connections
–Multifunction capabilities

12. Laser Printers
•Laser printer: Uses toner powder and technology similar to that of a
photocopier to produce images on paper:
–The standard for business documents
–Print one entire page at a time
–Generally faster and have better quality than ink‐jet printers
–Can be black and white or color
–Common print resolution for laser printers is between 600 and 2,400 dpi
–Use toner cartridges

14. Ink‐Jet Printers
• Ink‐jet printer: Sprays droplets of ink to produce images on paper:
–Usually 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
–Use ink‐jet cartridges
•Newer printers with full width printheadsare much faster
•Potential applications for the future
–Dispensing liquid metal, aromas, computer chips and other circuitry,
“printing” human tissue

15. Special‐Purpose Printers
•Photo printers
•Barcode, label, and postage
printers
•Portable printers
•Plotters and wide‐format
ink‐jet printers
•3‐D printers

16. Audio Output
•Audio output: Output in the form of voice or music
•Speakers
•Voice output systems
•Headphones and headsets
•Earphones and earbuds

17. Storage
•Primary storage
–Volatile
–Temporary
•Secondary storage characteristics
–Media (optical, magnetic)
–Capacity
–Storage devices
–Access speed
•Secondary storage
–Nonvolatile
–Permanent

18. Secondary Storage Devices

19. Floppy Disks
•Diskettes
•Floppies
•Portable storage media
•Floppy disk drives (FDD)
Traditional Floppy Disk

20. Hard Disks
•Use thicker, metallic platters for storage
•Faster than a floppy diskette
•Large capacity
•Sensitive instruments

21. Optical Disks
•Compact
•Permanent storage
•Laser beams reflect off pits
•Two common types
–CD
–DVD

22. Compact Disc
•Optical format
•From 650 MB to 1 GB capacity
•Rotation speeds vary
•Types
–Read only: CD‐ROM
–Write once: CD‐R
–Rewriteable: CD‐RW
–Picture CDs and Photo CDs
Digital Versatile Disc
•Digital Versatile Disk or Digital
Video Disk (DVD)
•Similar to CDs, but can store more
data
•Types
–Read only
–Write once
–Rewritable

23. Other Types of Secondary Storage
•Solid‐state storage
- Flash memory cards
•Widely used in notebook computers
•Used to record MP3 music files
- Key chain hard drives
•Key chain flash memory devices
•Connects to a USB port
•Internet hard drives
•Magnetic tape
- External storage
- Provides sequential access
•Information stored in sequence
•Slower than disks which provide direct access
- Magnetic tape streamers or tape cartridges used by both mainframes and
microcomput

24. A Look to the Future
Blu‐Ray Technology
•New standard in storage
•Blu‐Ray
–New disks use blue laser light instead of the red laser light used in
traditional CD players
–Disks may ultimately hold
•Over 30GB on one‐sided disks
•Over 50GB on two‐sided disks