Unit 1 � Information Technology Computer Hardware Functions

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Unit 1 � Information Technology Computer Hardware Functions Powered By Docstoc
					Information Technology

                BTA3O - Unit 1
4 Functions of a Computer System

                        The computer:

INPUT                   Collects data from you

STORAGE                 Saves information or instructions
                        into its memory.
PROCESSING              Interprets the data you input.

OUTPUT                  Displays information that has been
   Both Hardware & software are needed for a computer to perform these functions
Computer Hardware Functions



   Parts of computer system you can touch
    –   PERIPHERALS: components attached to
        computer via cables or wireless technology

   Brainstorm the many different types of input
Input Devices
   Keyboard
   Mouse
   Graphic Tablets (Stylus)
   Ports (USB, Serial, etc.)
   Modem
   Scanners (OCR, UPC)
   Digital Cameras
   Touch Screen/Touchpad
   PDA
Output Devices

   Monitors (CRT vs LCD)
   Printers (Impact vs. Non-impact)
   Audio (Speakers)
   Ports
   Modems

   Cathode Ray Tube (CRT)
   Liquid Crystal Display (LCD)
   Picture Elements (pixels) closer the pixels the
    higher the screen resolution
   Dot Pitch: diagonal distance between pixels
    (measures quality)

   Impact (line or dot matrix) – use hammers to
    transfer ink to paper surface
   Non-Impact (laser) – lasers magnetically
    charge toner as it rotates in its drum. Paper &
    toner are fused with heat to stamp the image
    onto the paper.

   Hard Drive
   Floppy Drives
   CD-ROM
   DVD
   RW-DVD
   Flash Memory

   List 2 advantages and 2 disadvantages of each
    storage device.
Disk Capacities

   Floppy:        1.4 MB
   Flash Memory   32 MB – 4 GB
   Hard disk:     20 GB – 1 TB
   CD:            700 - 900 MB
   DVD:           4.7 GB - 54 GB
   USB Drive:     8 MB and up
• Computer stores data in units (bits & bytes)
• BIT = Binary digIT
• Binary code language - 0 (off) or 1 (on)
  • 8 bit equal a character (i.e. letter, number)
• Memory or storage sized refers to the
  following forms of measurement
Measuring Memory
 BYTE       8 bits                    1 character

 KILOBYTE   1000 BYTES                thousand
 MEGABYTE 1,000,000 BYTES             million
          1000 KB
 GIGABYTE   1,000,000,000 BYTES       billion
            1000 MB

 TERABYTE   1,000,000,000,000 BYTES   trillion
            1000 GB
Magnetic Disk Storage
Disk Fragmentation

                   Fragmented disk shows
                    spaces where data has
                    been removed
                   Defragmenting has
                    placed all files in
                    contiguous spaces
                   Defragmenting a drive
                    will increase efficiency
                    for file retrieval
CD-ROM and Optical Disks

   CD-ROM (compact disk ROM)
    –   650 MB of information
   CD-R (compact disk-recordable)
   DVD-ROM (digital versatile disk)
    –   4.7 gigabytes
   DVD-ROM Dual Layer
    –   9.4 gigabytes (movies)
   Magneto-optical (MO)
    –   230 MB, 650 MB, 1.3 GB
    –   supports read and write operation

   Areas inside the computer base, specifically designed to
    facilitate the installation of additional equipment
   External Bays
    –   one open end for loading and unloading storage media such as
        diskettes, tapes and CD-ROMS
   Internal Bays
    –   completely enclosed - inside the case
    –   for hard disk drives
 Processing - CPU

Central Processing Unit (CPU)
 BRAIN of your computer
 Located on motherboard on single silicon chip
 Manufacturers:
   –   Intel (Pentium)
   –   AMD (Athlon)
   –   IBM (PowerPC)
   –   Motorola
Processing - CPU

   Follows instructions from ROM or a program (RAM) in
    order to process information.
    –   Performs calculations
    –   Executes instructions
    –   Communications with other workstation parts performing tasks
            Saving files
            Displaying output
            Printing document
CPU Components

         RAM        ROM


   Arithmetic Logic Unit (ALU)
    –   Intelligence of the computer
    –   Adds & compares numbers
    –   Processing completed in nanoseconds (a billionth of
        a second)

   RAM: Random Access Memory
    –   Temporary memory
    –   The space available to a computer to use while
        performing operations.
    –   The space is emptied out when the computer is
        turned off.
    –   Today’s applications require large amounts of
        temporary memory

   ROM: Read Only Memory
    –   Permanent memory – factory memory
    –   The memory programmed by the manufacturer
        containing system information.
    –   Permanent – Can’t be overwritten without special
    –   Determines basic functions of operation I.e. startup,
        shut down & placing character on the screen
Control Unit

   Directs information to proper places in computer
    –   calculation of information by the ALU
    –   Stores or prints material
Power Supply

   Converts the AC power to a more
    useable form for the computer.
   Newer machines use less power
    –   allows CPUs to run faster without

   System Software
    –   Operating System
    –   Utility Program
   Application Software
Operating Systems

   Interface between application and computer system.
   Examples of operating systems
     – Microsoft Windows, Unix, Linux, and Macintosh
Basic Form of User Interface

   Command-line (keyed commands)
   Menu-driven (choice of options)
   Graphical User Interface (GUI) - Icons
    represent files, folders or program)
Operating System Software

   Role of Operating System Software is to:
    –   File Management (manage files)
    –   Peripheral connections (coordinate tasks)
    –   Coordination of Tasks
    –   Memory Management (virtual memory manages system
    –   User Management (authenticate users)
    –   perform common computer hardware functions
    –   provide a user interface
    –   manage processing tasks
    –   provide networking capability
    –   control access to system resources
Utility Program

   Overall system maintenance & user-interaction with
    software & peripheral devices
   File Management (i.e. Windows Explorer or My
   Disk maintenance
    –   Disk scanning
    –   Disk fragmentation
   Backup
   Antivirus program
Application Software

   Word Processing
   Spreadsheet
   Publishing
   Presentation
   Database
   Web design
   Communication

   Network is two or more computers connected
   Requirements: NIC (network interface card)
   Benefits:
    –   Reduced Costs
    –   Sharing software & data
    –   Collaboration

   LAN (local area network)
    –   within small geographic area (a building or office)
   WAN (wide area network)
    –   wide geographic area
   Network Arrangements
    –   Peer-to-peer when a server is not involved
    –   Client-server when a server is involved

   Network is 2+ computers connected together
   Benefits:
    –   Reduced Costs
    –   Sharing software & data
    –   Collaboration
   Network Arrangements
    –   Peer-to-peer when a server is not involved
    –   Client-server when a server is involved
Networking: Use & Benefits

 –   Security through id and password
 –   Shared peripherals
 –   Shared storage
 –   Shared Applications
 –   Reliability and Resilience
 –   centralized backup systems for data recovery
 –   centralized virus protection
Types of Network Topologies
   Star Network
    –   Centralized hub (typical systems)
    –   Each machine runs independently from
        the other, but hubs connect
   Ring Network
    –   All machines arranged in a ring
    –   Built in redundancy with dual-ring
    –   Fibre optics and token ring
   Bus Network
    –   All machines on the same line
    –   Difficult to repair but inexpensive to
Types of Network Topologies

   Tree Network
    –   Combination of star and bus
    –   Within a network, stars are created
        linking nodes in specific areas
    –   The hub of each of these stars is
        connected along a bus backbone to
        maximize flexibility
Adapting to Change

   Adapting to an ever changing environment is a
    challenge all businesses must face.
    – Business end-users must define business needs,
       evaluate options, and select the hardware and
       software that provide a cost-effective solution to
       those needs.
    – The information system industry continues to
       undergo constant change; users need to be
       aware of recent trends to remain current.
   Hardware devices work together to perform input,
    processing, data storage, and output.

   Networks allow computers to share information and

   There are two main categories of software:
       systems software and application software

   An operating system (OS) is a set of computer
    programs that control the computer hardware to
    support users’ computing needs.
Interacting with Your Computer

   Acceptable Use of Computer Equipment
    –   Use own password
    –   Safeguard password
    –   Don’t install any unapproved software
    –   Connect only approved equipment
    –   Use files already scanned for viruses
    –   Report any known security breaches
    –   Access only your personal files
    –   Don’t use network for criminal, commercial or frivolous
        purposes (games)
Interacting with Your Computer

   Acceptable Use of Computer Equipment
   System Safety & Security
    –   Authentication
    –   Firewalls
    –   Encryption
Interacting with Your Computer
   Health Safety: Ergonomic Considerations
    –   Chair
    –   Desk
    –   Keyboard
    –   Mouse
    –   Monitor
    –   Lighting
    –   Documents
   Risk: RSI (repetitive stress injuries)
   Ergonomics: study of how workplace affects the worker
Interacting with Your Computer

   Social & Ethical Concerns in the Age of IT
    –   Threats to personal privacy (hackers)
    –   Definition of who owns what
    –   Cost to business if computer systems fail
    –   Dehumanization of the workplace (reduced need to
        interact with people)
    –   Potential to use information as a political or
        economic weapons
    –   Our dependence on technology

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