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Intro to Information Technology


... Apple II, the first computer to have color graphics. The Apple II ... Xerox Alto the first graphical user interface, went on to influence Apple and Microsoft ... – PowerPoint PPT presentation

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Title: Intro to Information Technology

Intro to Information Technology
  • Wednesday, September 18th
  • Chapter 11 Computer Hardware
  • Sites of Interest

  • Identify the major types, trends, and uses of
    microcomputer, midrange, and mainframe computer
  • Outline the major technologies and uses of
    computer peripherals for input, output, and
  • Identify and give examples of the components and
    functions of a computer system.
  • Identify the computer systems and peripherals you
    would acquire or recommend for a business of your
    choice, and explain the reasons for your

History of Computers
The 1970s
  • 1971 Intel makes the first microprocessor at a
    speed of 108 kHz
  • The UNIX operating system was written in the new
    language, C
  • One of the first personal computers, the Altair,
    came in a kit and you had to build it yourself
  • 1976 The Cray-1, the worlds fastest
  • 1977 The debut of the Apple II, the first
    computer to have color graphics

The 1970s continued…
  • 1977 The debut of the Apple II, the first
    computer to have color graphics
  • The Apple II had 4 KB of RAM and cost 1298
  • The Commodore PET began the line of lost cost
    Commodore PCs
  • The VAX architecture was introduced in 1977 and
    cost 200000
  • VisiCalc, the first spreadsheet program was
    created for the Apple II and it was the father of
    all productivity software

The 1980s
  • 1982 IBM launched its first PC, powered by DOS,
    written by a tiny company named Microsoft
  • Xerox Alto the first graphical user interface,
    went on to influence Apple and Microsoft
  • 1982 Commodore 64 brought affordable personal
    computing to the masses
  • 1984 The Apple McIntosh
  • 1984 WordPerfect the first word processor

The 1980s continued
  • 1985 The first multimedia computer, the
    Commodore Amiga
  • 1986 - The Intel 80386 Processor, the first 32
    bit processor
  • The C programming language
  • The Apple McIntosh II the first color graphics
    McIntosh computer
  • The birth of 3D graphics

The 1990s
  • Microsoft Windows 3 made PCs as easy to use as
    Apple McIntosh
  • Apple sues Microsoft over the similarity of the
    graphical user interface
  • AMD 386 first processor not built by Intel
  • Virtual Reality

The 1990s continued
  • 1992 Linux is created
  • 1993 The Intel Pentium processor
  • The World Wide Web
  • Windows 95 was introduced after 18 months of
  • E- Business and E-Commerce

Computer System Categories
  • Microcomputers
  • Midrange Computers
  • Mainframe Computers

  • The most important category for business people
    and consumers
  • Usually referred to as a personal computer (PC)
  • Types are handheld, notebook, laptop, desktop,
  • Microcomputers can perform tasks such as complex
    mathematical calculations, graphical applications
    such as computer-aided design, etc

  • Network computers
  • Thin client means a minimum of programs and
    processing occur on the machine itself
  • Software, data storage, and operating system are
    provided by the Internet and accessed through a
  • Usually does not have a local hard drive

  • Information Appliances
  • PDAs Personal Digital Assistant
  • These have touch screens, use a stylus for
    handwriting recognition, and are usually very
    small (hand-held)
  • Other appliances exist such as WebTV which allows
    you to surf the net from your TV

  • Computer Terminals
  • Can be dumb (limited processing) or intelligent
    (more processing)
  • Intelligent terminals are found in areas such as
    transaction terminals, found in banks, stores,
    factories, etc
  • Capture data on terminal, and data is managed and
    processed by servers or other computers on the

Midrange Computers
  • Multi-user systems that can manage networks of
    PCs and terminals
  • They are less powerful than mainframes, but more
  • Used for such tasks as network management, data
    warehouse management, and assisting mainframes
    with telecommunications, etc

Mainframe Computers
  • Large, fast, powerful
  • Large storage capacities
  • Used to handle processing needs for major
    corporations and government agencies
  • Used for scientific calculations
  • Supercomputers can have more than one processor

Parts of a Computer
  • Processing
  • Input
  • Output
  • Memory
  • Data Storage

A Computer System
  • The heart of the computer is the Central
    Processing Unit (CPU)
  • Two main divisions
  • Control Unit Interprets instructions and
    directs processing
  • Arithmetic-Logic Unit Performs arithmetic
    operations and performs comparisons
  • Also includes circuitry for registers and cache
    memory for high speed, temporary storage

  • The clock
  • This is what controls the processing in the CPU
    and at what speed it runs
  • With every clock tick, the CPU executes an action
  • Speed
  • Usually expressed in cycles per second, or hertz.
  • Todays computers have speeds expressed in
    megahertz (MHz), a million cycles per second, or
    gigahertz (GHz), a billion cycles per second

  • Buses
  • Circuitry paths that interconnect microprocessor
    components for movement of data and instructions
  • ISA Bus
  • Industry Standard Architecture
  • PCI Bus
  • Peripheral Component Interconnect
  • Used to connect peripheral devices

  • USB
  • for Universal Serial Bus, an external bus
    standard that supports data transfer rates of 480
    Mbps (480 million bits per second). A single USB
    port can be used to connect up to 127 peripheral
    devices, such as mice, modems, and keyboards
  • AGP
  • for Accelerated Graphics Port, a new interface is
    based on PCI, but is designed especially for the
    throughput demands of 3-D graphics
  • Definitions from

  • Since CPUs generate a lot of heat, a cooling
    mechanism is needed
  • A metal heat sink is placed over the processor.
    It draws the heat out into its spikes
  • A fan on the heat sink blows the hot air away
    from the processor

  • Keyboards
  • Can easily type in instructions
  • Mouse
  • Enables the user to point and click
  • Works with a graphical user interface for easy
  • Trackball
  • Similar to a mouse, but you move the ball
  • Touchpad
  • Move your finger on the pad to move the cursor

  • Popular types of processors
  • Intel
  • Pentium, Pentium II, Pentium III, Pentium IV
  • Celeron
  • AMD
  • Athalon
  • Duron

  • Touch screen
  • Users touch the screen to move the cursor or to
    make selections
  • Pen-based computing
  • Many hand-held devices use small pens to draw on
    the screen, or a designated area.
  • Speech Recognition
  • Users speak to a computer and it interprets their

  • Optical Scanning
  • Read text or graphics and convert them into
    digital input for the computer
  • Reflected light patterns of the data are
    converted into electronic impulses that are
    accepted as input
  • OCR or optical character recognition can be used
    to read codes or characters such as UPC codes

  • Magnetic Stripe
  • Iron oxide coating holds up to 200 bytes of
  • Digital Cameras
  • Can take pictures and load them on to your
  • Magnetic Ink Character Recognition
  • Used on cheques for banks to sort and process

  • Serial Ports
  • This is how keyboards and some older mice connect
    with the computer
  • Only 1 bit of information is transmitted at a
  • PS/2 Ports
  • Mice or keyboards connect to computers with this
    type of port
  • Developed to free up a computers serial port
  • Most new devices use USB ports because of their
    high speeds of data transfer and one port can
    connect up to 127 devices

  • Video
  • Video monitors use CRT (Cathode Ray Technology)
    similar to TVs
  • Liquid crystal displays (LCD) are usually used
    for portable computers
  • LCD gives a flat screen with bright colours and
  • LCD displays need less electric current and have
    a thin, flat display

  • Video continued…
  • The quality of the video display can depend on
    the type of video card that is used
  • Video cards can be plugged into either a PCI or
    AGP bus
  • They have their own storage, now usually between
    16 and 32 MB
  • Resolution settings also depend on the video card
  • Most common resolution on a 15 monitor is
    800X600, which is the screen size measured in

  • Printers
  • Dot Matrix
  • Old style of printers than printed across the
    page one line at a time
  • Very slow printing
  • Inkjet
  • Spray ink on to a page one line at a time
  • Popular, low cost personal printers
  • Good quality and fairly quick printing

  • Printers continued…
  • Laser
  • Use an electrostatic process similar to a
  • Fast, high quality output in black and white
  • Colour is very expensive
  • Popular for businesses
  • Popular printer brands include HP, Canon,
    Lexmark, and Epson

  • Printers were traditionally connected to the
    computer by a parallel port
  • Parallel ports have 25 pins and transmit more
    than one bit per second (unlike serial ports)
  • Now many printers connect through the USB bus

  • Sizes of memory
  • One Bit one character, either a one or a zero.
  • This is the simplest information that a computer
    can process
  • Binary expresses data in terms of a sequence of
    1s and 0s
  • 1s and 0s correspond to On/Off, True/False, 5
    volts/0 volts

  • Sizes of memory continued…
  • A byte is 8 bits
  • A nibble is 4 bits
  • A KB, or kilobyte, is 1024 bytes
  • A MB, or megabyte, is 1024 kilobytes
  • A GB, or gigabyte, is 1024 megabytes

  • RAM Read Only Memory
  • This can also be referred to as direct memory
  • Each storage position
  • Has an unique address
  • Can be individually accessed in the same amount
    of time without having to search through other
    storage positions
  • Is used for data that needs to be retrieved
  • Is used during the running of applications
  • Storage capacity is expressed in MB (megabytes)

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  • Primary storage (main memory) of a computer
    consists of semiconductor memory chips
  • Semiconductor memory has a small size, great
    speed, and shock and temperature resistance
  • Provides working storage for your applications
  • One disadvantage is that is requires a constant
    supply of uninterrupted electrical power

  • RAM continued…
  • Usually machines today come with between 128 and
    256 MB of RAM
  • RAM is an important factor in how fast your
    computer runs applications
  • More RAM is needed for applications that need a
    lot of temporary storage, such a photo-processing
    applications, and 3D games
  • RAM is volatile i.e. the contents are lost as
    soon as power to the memory is interrupted

  • ROM Read Only Memory
  • This memory can only be read, not erased or
  • Control instructions and low level programs can
    be burned into this memory during manufacture
  • This is also known as firmware
  • This memory is non-volatile i.e. it doesnt
    require power to keep the contents in memory

  • L2 Cache
  • As discussed earlier, the processor has a small
    amount of storage right on the chip
  • A Level 2 Cache is memory external to the
    processor, it is stored on a chip outside the
  • Now manufacturers are starting to build L2 caches
    right on the chip

Data Storage
  • Need to backup contents of main memory so
    information is not lost when the power is shut
  • These devices and technologies are known as
    secondary storage
  • Three common types are
  • Magnetic disks
  • Magnetic tape
  • Optical disks

Data Storage
  • Magnetic disks
  • Fast access and high storage capacity for a
    reasonable cost
  • Magnetic disk drives contain metal disks that are
    coated on both sides with a iron oxide recording
  • These disks are mounted on a vertical shaft that
    rotates them at speeds of between 3600 7600 rpm

Data Storage
  • Magnetic disks continued
  • Electromagnetic read/write heads are positioned
    on arms between the disks to read and write data
    in concentric circles
  • Data is recorded as tiny magnetized spots to form
    binary digits that the computer can read
  • Disks have billions of storage positions

Data Storage
  • Magnetic Disks continued…
  • Floppy disks
  • Polyester film disks coated with iron oxide
  • Rotates inside a plastic jacket
  • Most common floppy disk is the 3 ½ inch disk than
    can hold 1.44 MB of data

Data Storage
  • Magnetic Disks continued…
  • Hard Disk
  • Combine magnetic disks, access arms, and
    read/write heads in a sealed module
  • This allows higher speeds, greater data recording
    densities, and closer tolerances
  • Hard drives can usually store up to many
    gigabytes of data
  • Hard drives are where the operating system and
    applications are permanently stored

Data Storage
  • Magnetic Disks continued…
  • RAID Redundant arrays of independent disks
  • Replace large capacity mainframe disk drives
  • Many interconnected microcomputer hard disk
    drives provide large capacities with high access
    speeds since data is accessed in parallel
  • If one disk fails, data can be recovered from one
    of the others

Data Storage
  • Magnetic Tape
  • Data is recorded on the iron oxide coating of the
    magnetic tape
  • Can hold over 200 MB of data
  • Most commonly used for backup storage and
    archival of data
  • This is a low-cost technology that supplements
    magnetic disk storage

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Data Storage
  • Optical Disks
  • A laser records data by burning permanent
    microscopic pits in a spiral track
  • Drives use a laser device to read the binary
    codes formed by the pits
  • CD-ROM disks can hold up to 600 MB of data, which
    is equivalent to 400 1.44 MB floppies, or 300000
    double spaced pages of text

Data Storage
  • Optical Disks continued
  • CD Burners can be used to record data on CD-R
    disks (can only record on once) and CD-RW disks
    (can be recorded on over and over)
  • DVD Digital Video Disk
  • DVDs can hold between 3 and 8.5 gigabytes of data
  • DVDs are expected to eventually replace CDs and
    CD-ROMs because of their large storage capacity
    and excellent quality