Computer Technology Overview for Educators

Types of Hardware

• Basic
  • Central
    • CPU (Pentium, etc.)
  • Storage
  • I/O

• Communication

• Multimedia
  • Graphic
  • Audio
  • Video

Measuring the Data

• Bit
  • The tiniest element of computing is an electric current that is either on or off. This is referred to as a 1 (on) or a 0 (off ) and constitutes a bit.

• Byte
  • Eight bits taken as a single unit. This is convenient for humans because a byte also can describe a single letter.

Measuring the Data (cont.)

• Kilobyte or K
  • One thousand bytes (actually 1024 or 210). This approximately equals the text information on a typewritten sheet.

• Megabyte or Meg
  • One million bytes (actually 1,048,576 or 220). About the text information in the Bible.

Measuring the Data (cont.)

• Gigabyte or Gig
  • One billion bytes (actually 230). This approximately equals the text and picture information in the Encyclopedia Britannica.

• Terabyte
  • One trillion bytes (actually 240). All the information needed to create the movie Toy Story.

Where is the Information Stored?

• Central Memory

• External Memory

Central Memory

• ROM
  • basic information and booting
  • Not changeable by the user

• RAM
  • This memory contains the programs and data that you use while computing.
  • Volatile -- Gets erased every time the power is switched off.

External or Permanent Memory

• Floppy disk or diskette

• Hard Drive

• CD-ROM

• Networks

Disks, Floppy Disks, or Diskettes

• Come in 5.25” and 3.5” sizes

• 3.5” disks currently hold 1.44 MB

• Magnetic medium

• Subject to wear and tear from user handling and from use in the computer

Hard Drives

• A sealed drive, usually inside the computer

• Common sizes range from 200MB to 8 GB

• Magnetic medium

• Subject to wear and tear from use in the computer, but insulated from dust and other contaminants

• Hard drives can and do fail so data should be backed up. When hard drives fail, all info is lost

CD-ROM drives

• CD-ROM stands for Compact Disc Read Only Memory

• Hold 680MB

• Optical medium

• CD-ROMs are less vulnerable to wear and abuse than floppies, but can fail due to dirt or scratches

Networks

• LAN (Local Area Network)

• WAN (Wide Area Network)

• Internet

LAN

• Fairly easy to create
  • especially with Macs

• Two types
  • server (one main computer)
    • usually star configuration
  • peer-to-peer (all computers equal)
    • usually daisy-chained
  • Can be combinations of the above

Input and Output (I/O)

• Input
  • keyboard, mouse, scanner, etc.

• Output
  • monitor, printer, etc.

Multimedia

• Three Types
  • Graphics
  • Audio
  • Video

• Usually in digital format
  • might have to convert

Obtaining MM Materials

• Create

• Digitized

• Convert

Graphics (overview)

• Bitmaps
  • resolution
    • 72 ppi (typical monitor)
    • 300, 600, etc., dpi
  • color depth
    • 1, 8, 24, etc., bits
  • size
  • compression
    • lossy, lossless

Graphics (creating )

• Draw (vector)
  • Creates vector objects
  • easily moved, edited, and resized
  • must be converted to bitmaps for display
  • usually for graphic art

• Paint (raster)
  • creates bitmaps directly

Graphics (digitized)

• WWW

• Clip-art libraries

• photo-disks

Graphics (converting)

• Scanners
  • flatbed
  • handheld

• Video conversion (still video)
  • video capture

Audio (overview)

• Three types
  • digital files
  • MIDI
  • CD audio

• Need audio card
  • Has internal mixer

Audio (creating)

• digital files
  • Record from...
    • Microphone
    • high-level input

• MIDI

• CD audio

Audio (digitized)

• WWW

• CD’s with background, ambient, etc. sounds

• MIDI collections

Audio (converting)

• Microphone
  • use internal capture/edit program
  • or specialized capture/edit program

• Capture from external source
  • CD
  • tuner
  • TV audio
  • etc.

Audio (I/O)

• Input
  • Microphone
  • CD-ROM
  • MIDI keyboard

• Output
  • Amplifier
  • Amplified speakers

Video (overview)

• Need video card
  • To convert from NTSC to digital

• Three types
  • live
  • transmitted
  • recorded
    • videotape
    • videodisc

Video (creating)

• Animations

• Morphing

• Transition editor
  • Adobe Premier, etc.

Video(digitized)

• WWW

• CD’s with video

• Video disks and tapes
  • but must be converted

Video (converting)

• Convert from external source
  • use internal capture/edit program
  • or specialized capture/edit program

Video (direct usage)

• Play through TV

• Controls
  • videotape
    • remote or buttons on player
  • videodisc (CAV and CLV)
    • Level I
      • remote, bar code reader
    • Level III
      • via computer

Video (I/O)

• Input
  • Video camera
  • Videotape (magnetic)
  • Videodisc (optical)
  • Cable TV

Communications

• To networks

• Directly to other computers

• To the internet