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Bits and Bytes

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Title: Bits and Bytes


1
Bits and Bytes!
  • Concepts of ICT explained

2
A computer..?
  • Job specification? Desktop publishing, video
    editing, sound editor, internet browser,
    calculates wages......

OUTPUT
INPUT
PROCESSES
A computer accepts Input, Processes it in some
way, then displays or outputs the information.
3
Types of Computers
  • Mainframe
  • Expensive with large storage capacity
  • Can cope with very high volumes of transactions
  • Typically used by banks, insurance companies,
    government organizations and large corporations
  • Hold vast databases of information which can be
    accessed quickly and updated by a large number of
    users at the same time and support a large number
    of peripherals
  • Expected to run 24 hours a day, 365 days a year

4
The PC/ Personal Computer
  • Types Desktop/Laptop or Notebook/ Personal
    Digital Assistants (PDAs)/Palmtop computers
  • Laptop - Portable/Own integral screen and
    keyboard/May have own rechargeable batteries or
    require electric power
  • Main uses of PCs are as desk-top business
    computers used for word processing, small
    business accounts, financial planning, or as home
    computers.
  • Capable of stand alone or networked use, possible
    to link PCs together to share storage
    facilities, printers, or files of information.

5
  • Network server Administers, supports and
  • protects security of a computer network
  • Dumb Terminal - An input or output device with
    no processing power of its own,
  • Consists of a keyboard, display screen and a
    communication link to a mainframe computer.
  • Accepts input from user, displays results,
    processing done by server.
  • Intelligent terminal - a terminal which retains
    a program and allows processing of data to be
    carried out without further access to the host
    computer.

6
Hardware
  • The physical components that make up a computer
    system
  • Includes
  • monitor,
  • keyboard,
  • cables,
  • memory,
  • printer and the case containing the computer
    itself (the processor)

7
Software
  • Term used to describe the sets of instructions or
    programs that tell the hardware what to do and
    includes the programs which we use on the
    computer e.g. Word processing, games,
    encyclopedia
  • Two types of Software
  • System Software
  • Application Software

8
System software
  • Manages files and storage, Controls devices,
  • Recognizes input, Sends output to screen,
    Communicates with peripherals
  • Main piece of systems software is the OPERATING
    SYSTEM.
  • Operating systems include DOS, UNIX, Windows 3.1,
    95, 98, 2000, XP.
  • DRIVERS Special piece of software to enable
    operating system to control hardware e.g.
    Certain printers require separate drivers,
    compatible with current operating system, to be
    installed before printer will work.

9
OPERATING SYSTEM
  • Automatically loads when computer is
  • switched on, otherwise computer will not work.
  • Functions
  • Boots up the system , controls input and output
    devices, manages the transmission of data between
    application software, storage device and RAM.
  • Translates commands received from the
    applications software word processing programs,
    spreadsheets etc into instructions specific to
    the hardware
  • Distributing RAM, controlling input and output
    devices, allowing/preventing access to
    authorised/unauthorised users

10
APPLICATION SOFTWARE Generally Applies To
Programs Written For A Particular purpose
e.g. Word, Excel, Powerpoint, Access,
Desktop publishing
  • WORD PROCESSING
  • A programme specifically developed for the typing
    and production of letters, reports and documents.
  • Unlike typewriter, text can be saved and
    modified.
  • SPREADSHEETS
  • Microsoft Excel - Commonly used spreadsheet
  • Excel workbooks - contains
  • the file in which work is done and data stored
  • Each workbook contains many worksheets
  • Each spreadsheet consists of columns down and
    rows across.
  • Spreadsheets - largely are used for calculations
    from simple additions to complicated formulae
  • Graph feature - range of options used for
    comparisons of data

11
DESKTOP PUBLISHING
  • A Programme for producing professional-quality
  • reports, booklets and magazines.

Publisher provides pre-designed templates for a
wide range of documents newsletters, cards,
banners, flyers, brochures, calendars,
advertisements. Templates can be modified or the
user can create from scratch.
  • MICROSOFT ACCESS
  • A program that enables creation of and working
    of databases
  • MICROSOFT POWERPOINT
  • A program that creates visual slides for a
    presentation and handouts for use when addressing
    an audience

12
Memory
  • RAM (Random Access Memory)
  • ROM (Read Only Memory)
  • Cache Memory

13
Random Access Memory(RAM)
  • RAM is temporary, fast memory
  • Working memory - holds lists if instructions
    that it is currently working on and handles work
    since last saved
  • RAM is volatile and requires a constant supply of
    electric power , data is lost when the power to
    the computer is turned off
  • Saving work removes it permanently from RAM to
    disk
  • Additional RAM chips can be added by installing a
    memory-expansion card
  • The more RAM, the faster the computer operates,
    the more programs that can be open simultaneously
    and the faster they perform
  • A certain minimum RAM is required to install and
    run programs
  • 64 Mb or 128Mb RAM minimum now required to run
    most programs

14
ROM (Read Only Memory)
  • A memory that holds data or special instructions
    for computer
  • operation, such as starting the computer or
    putting characters on the screen.
  • Contents of ROM are permanently fixed when the
    computer chip is made
  • Information in ROM remains intact even when
    computer is switched off
  • Computer can only read what is in ROM, it
    cannot alter it
  • ROM cannot be altered by the computer or
    programmer - the actual content of ROM is fixed
    at the time of its manufacture. ROM can only be
    changed by changing the computer.

15
Cache memory
  • A special high-speed memory area linked to the
    processor that the CPU can access quickly.
  • Frequently used data is stored here saving the
    processor from having to read from the hard disk
    all the time. Allows the CPU to run faster
    because it doesnt have to take time to swap
    instructions in and out of RAM.
  • Measured in bytes ranging 128kB - 512kB

16
Other forms of memory
  • Video RAM (VRAM) used to store display images for
    the monitor.
  • Determines how fast images appear and how many
    colours are available.
  • Video memory chips are essential when running
    programs that display a lot of graphics.

17
Memory Measurement
  • Bit Short for Binary Digit-the smallest unit of
    Data that
  • the computer can handle. Data is represented by
    on and off
  • states of the computers electronic circuitry.The
    binary digit for on is 0 and off is 1.
  • Character Combination of bits(0s and 1s) are
    used to represent charactersletters,digits and
    special symbols like, etc.
  • Byte A fixed number of adjacent bits that
    represent characters are called a byte-this is
    the amount of memory needed to store one
    character such as a letter or a number.Eight bits
    are used to represent a character.
  • Field A collection of related characters.
  • Record A collection of fields that relate to a
    single unit is a record.
  • File A grouping of related records
  • Kilobytes equal to 1024 bytes or characters (KB)
  • Megabytes equal to 1024 kilobytes (approx. one
    million bytes (MB))
  • Gigabytes equal to one billion bytes (GB)

18
Computer Power
  • CPU Speed
  • The amount of RAM
  • Cache memory
  • Hard disk size
  • Clock speed

.
19
C.P.U.
  • The central processing unit is the little chip in
    personal computers that controls everything.

20
Hard Disks
  • Enable large amounts of data to be stored
  • accessed, and read at very high speeds
  • Consists of magnetic storage plates encased in a
    hard disk drive
  • The computers main storage device holding the
    files for the operating system plus the program
    and data files

21
The System Clock
  • Every microprocessor contains a system
    clock.Controls how fast the operations within a
    computer take place.
  • Processing speeds are expressed in megahertz(MHz)
  • The higher the MHZ speed - the faster the
    computer

22
Systems Software Utilities
  • Utilities are programs that are designed to
    assist with the routine tasks of running a
    computer system
  • Examples- programs to copy or delete files,
    rename files, and format new disks
  • Text editors (used to write and amend programs)
    and debuggers (used for finding errors in
    programs) also available.

23
  • Graphical User Interface (GUI)
  • Incorporates four elements Windows, Icons, Menus
  • and a Pointing Device
  • Apple Macintosh Finder or Microsoft Window use a
    computerised desktop as the interface between the
    user and the operating system. Pictures or icons
    represent such items as disks, files and
    programs. A GUI has pull-down menus that allow
    the user to select from a predefined list of
    command choices. A GUI uses a mouse to allow the
    user to point at and select the items or commands
    that are required.
  • GUI is easy to use icons are self-explanatory a
    lot of similarity between basic functions of all
    Windows-based software.

24
Data - Stages 3 stages Input
Processing Output
  • Input Data is input into the computer by typing
    on a keyboard or using a scanning device such as
    a barcode reader in a supermarket
  • Processing Once data is input it is processed in
    the brains of the computer- (Central Processing
    Unit)
  • Output Data can be distributed to users via Soft
    Copy or Hard Copy
  • Soft Copy - Temporary, Displayed on monitor,
    Information vanishes once monitor is turned off
  • Hard Copy - Permanent, Printed copy on paper,
    acetate or microfilm

25
Input devices
  • Inputting methods have evolved dramatically over
    the years
  • from the earlier use of keyboard, punched cards
    and paper tape.
  • Input methods include
  • The keyboard
  • The mouse
  • Trackerball
  • Scanner
  • Touchpad
  • Light Pen
  • Joystick
  • Voice Input
  • Graphics pad
  • Magnetic disk and tape input
  • Document readers
  • Web Cam
  • Digital camera

26
  • Keyboard is the slowest means of input
  • Most used input device
  • Its familiar
  • Easy to operate
  • Mouse
  • Many different types including cordless
  • Gives fine conrol over use of applications
  • Access to menus on Rightclicking
  • Tracker ball (track ball)
  • A pointing device which you rotate to move the
    mouse cursor commonly found on notebook
    computers

27
  • Scanners
  • Scanner - used as a means of capturing an
    existing two-dimensional image - a drawing or a
    photograph that could not be input using a
    graphics
  • pad
  • image scanners divide a picture into a matrix of
    tiny dots each of which is stored in a file in
    the computer.
  • It is then possible to use this file with an
    existing text file in order to combine pictures
    with text as in a newspaper
  • Optical Character Recognition (OCR)
  • Enables information to be automatically read
    from a printed document
  • OCR scanners can recognise typed and neatly
    handwritten material.
  • OCR is used by organisations like gas,
    electricity and credit card companies, all of
    whom need to process large numbers of similar
    documents in a short space of time.
  • Video scanners
  • The video scanner uses a video camera to capture
    an image for processing either of an existing
    two-dimensional picture or of a three dimensinal
    object
  • Video scanners will generally offer a higher
    resolution than image scanners

28
  • Touch screens (touch pads)
  • Designed to avoid the use of a computer keyboard,
    the user will simply touch the appropriate icon
    or other reference on the screen.
  • Action will be sensed by the computer, and the
    option chosen will be acted upon.
  • Light Pens
  • Device used in conjunction with special hardware
    and software that shines light on to a VDU screen
    to indicate a choice from a menu or to input a
    location in graphics work
  • In libraries, bar codes are read by using a light
    pen or wand

29
  • Joysticks
  • Input device for a microcomputer.The stick as it
    moves (usually in one of eight directions) is
    able to control the movement of a shape on the
    screen. Sometimes there are 2 joysticks enabling
    a screen game to be played by 2 players.
  • Voice Input
  • Possible to programme a computer to respond to
    voice commands
  • Present voice recognition systems need to be
    trained to cope with a particular voice
  • Must be restrained if the user gets a cold or has
    a sore throat

30
  • Graphics pad
  • Used to input graphic image to a computer
  • Freehand images can be input by drawing with the
    stylus
  • on the bed of the pad.
  • Existing drawings may be traced by the stylus on
    the bed alternatively they may be input by using
    a cursor similar to a mouse
  • The cursor is positioned in turn over the key
    points on the drawing and one of the buttons on
    it is pressed
  • The computer records these points and joins them
    together as necessary to define the computer
    image.
  • When used to input existing drawings, graphics
    pads may also be called digitisers.
  • They are used by architects to design buildings,
    and as part of CAD systems in engineering

31
Magnetic disk and tape input
  • Both widely used for the storage of computerised
    information
  • A computer storage device that looks rather like
    an LP record that has the same magnetic coating
    as an audio
  • Information is recorded onto and read from the
    surface of the disk in much the same way as a
    domestic cassette tape recorder is used to record
    and play back music
  • Magnetic tape is the computer equivalent of the
    reel-to-reel tapes found on professional tape
    recorders
  • Data can be transferred from magnetic disk or
    tape far faster than it can be input from any
    other device
  • Speeds of input from magnetic tape or disk are
    termed data transfer rates
  • Magnetic ink character recognition (MICR)
  • Enable the fast and efficient clearing of cheques
  • Characters are printed in a special ink that can
    be magnetised to give off a unique magnetic field
    that enables each character to be read
  • Used by the banks as a way of speeding up the
    cheque clearing system- input speeds can be
    anything up to 2000 cheques a minute

32
Card Readers
  • A device that reads information held in the form
    of
  • a magnetic strip on a plastic card e.g. Credit
    card,
  • ATM card
  • Bar-code readers
  • An arrangement of vertical bars and spaces that
    can be read by an optical scanner and used as a
    means of identifying products or stock items
  • Seen on most products purchased in supermarkets,
    inside library books, and on such items as
    freezers and computers. In supermarkets, each
    product carries a unique bar code that can be
    used both to calculate the size of the bill at
    the point-of-sale (POS) terminals (or check-outs)
    and for stock control.
  • System operates from a central computer which
    controls the POS terminals.
  • When shoppers goes through a check-out, each item
    is passed over the scanner which reads the bar
    code and refers to the central computer for the
    description and price.
  • Information is relayed to the check-out, where it
    is displayed on a customer panel printed on a
    receipt. Stock level for the item purchased will
    be reduced , providing management with up-to-date
    stock information and enabling more efficient
    stock control and ordering.

33
  • Document readers
  • Can be read by humans as well as by machines
  • Used where there is a need to be able to process
    large volumes of similar documents, like cheques
    or gas bills Automated processing of cheques
    quickly
  • Computer marking of multiple choice answer sheets
  • Reading of large volumes of credit card payment
    slips
  • Web Cams
  • Allows two way communication including sound and
    video as well as text
  • Digital cameras
  • Images are stored digitally in memory in camera
  • Pictures can be transferred to computer and
    edited digitally

34
Computer Output
  • Output Once the data has been processed,
    information can be distributed to users.
  • Computer output can take the form of a display on
    a screen,
  • a print-out, or transfer of information on to a
    magnetic tape or disk.
  • Most output falls into one of two categories
    hard copy or soft copy.

35
  • Hard copy is output in a permanent or touchable
  • form e.g. printed form such as on paper or
    microfilm. May be produced either on separate
    sheets or on continuous stationary taking the
    form of folded and perforated lengths of paper
  • Soft copy is information that is displayed
    visually on a screen or monitor - temporary once
    the monitor is turned off or new information is
    required, the old information vanishes.
  • Also can be in audio form, as in speech or music

36
  • Visual output
  • Most common form of soft-copy output is
    information displayed on a screen or cathode-ray
    tube(CRT)
  • The VDU enables a user to input information to a
    computer by using a keyboard, mouse or touch
    screen facilities and to view output on a CRT
  • Two factors limit the use of the CRT its weight
    and the amount of power it consumes
  • Liquid-crystal displays (LCDs) similar to those
    found on some digital watches are both light and
    economical enough to be widely used for portable
    computers

37
Computer output on microfilm (COM)
  • As an alternative to printed output, another form
    of hard copy is computer output on microfilm or
    microfiche
  • COM is the recording of what would otherwise be
    printed output direct in reduced form on to
    either rolls or sheets of photographic film
  • Microform can store documentary information with
    textual and graphical content
  • Structure can be either microfilm (a continuous
    reel) or microfiche (a grid pattern)
  • Microform reduces storage space requirements by
    approximately 95 of that required by paper
    documentation

38
Audio output Covers the range from the simple
beep to full speech synthesis. Speech
synthesis is the production of a sound
corresponding to spoken words and it is of great
use where a user is unable to look at a CRT or is
occupied with another. Computer Speakers Have
the same function as hi-fi music speakers used in
the home stereo systems. Differ from conventional
speakers in that they are self amplified and
magnetically shielded. Most speakers are AC
powered and have separate volume tone
controls.
39
Printers
  • Two most common types of printers
  • Inkjet Printers
  • Laser Printers
  • Also third category - Matrix Printers

40
  • Ink-jet printers
  • Work by using tiny jets to spray ink at high
    speed onto the paper
  • Forms characters by projecting the ink from the
    small ink nozzles (the same way as by the
    dot-matrix printer) on to the paper - for this
    reason are termed a non-impact printer.
  • Ideal for low volume printing with high quality
    where speed is not priority
  • Major advantage over a dot-matrix printer is low
    level of noise
  • Laser printers
  • Shares the same image-printer technology as the
    photocopier.
  • Print image is produced by a laser beam which
    scan across the print drum, line for line as the
    print cylinder rotates.
  • High quality at high speed

41
Dot-matrix printers
  • Gets name from way in which a number of needles
    in the print head are used to print text as a
    series of dots using a carbon ribbon.
  • The more pins the print head has, the higher the
    quality of print
  • The speed at which a dot-matrix printer is able
    to operates depends on which typeface is being
    printed
  • Typical speeds may range between 40 and 500 c.p.s
    according to the print quality.
  • Noisy and not high quality
  • Suitable for high volume/low quality printing
    e.g. printing company payslips
  • Widely used as a micro-computer peripheral

42
  • Thermal printers
  • Use heat to transfer the image from the print
    head to the paper.
  • Text and images are made up from a series of
    dots, in common with
  • other matrix printers, but with this process the
    print head may be either a fixed array of thermal
    elements
  • Daisy-wheel printers
  • This printer takes its name from a flat disc with
    a number of stalks or petals radiating from its
    centre each of which has a character at its tip.
  • Daisy wheel rotates at high speed and the petals
    are pushed on to a ribbon which, in turn
    transfers the characters to the paper.
  • Line printer
  • Gets its name from the way in which it prints a
    line of text at a time.
  • Two types- chain printer and the drum printer.
  • Main feature is their speed, the fastest printing
    text at around 5000 lines per minute. This is
    achieved by hitting the paper against the
    character and printer ribbon.

43
Graph plotters
  • An output device similar to a printer but
    normally
  • allows printing of larger images
  • The graph plotter is a specialist device designed
    to produce high-quality pictures and designs.
  • Unlike matrix printers, a graph plotter
    reproduces the human action of drawing by using a
    pen.
  • Widely used by architects and designers of all
    kinds
  • Two types of graph plotter- flatbed and drum

44
Peripherals
  • A Peripheral is any device that is connected to
    and controlled by a computer but external to the
    CPU etc.
  • Peripherals include
  • Printers
  • Loudspeakers
  • Scanners
  • Digital camera
  • Microphone

45
Storage
  • Primary and Secondary Storage
  • The Term primary storage (main memory) refers to
    RAM
  • Secondary storage is auxiliary storage - any
    storage device designed to retain data and
    instructions (programmes) in a relatively
    permanent form.
  • Secondary storage is non-volatile, meaning that
    saved data and instructions remain intact when
    the computer is turned off.

46
CD-ROM Compact Disk Read
Only Memory
  • Widely used for reference material and training
    purposes, has huge storage capacity
  • Ideal for storing all forms of images including
    video sequences which take large amounts of
    storage space
  • Not used for storage of documents which require
    regular updating.
  • Speed of CD ROM drive is regularly being improved
  • Standard CD-ROMS can only be written to once,
    CD-RW disks can be written to more than once
  • A CD-writers/burner used to record or copy to a
    CD
  • CD-ROMS now being over taken by DVDs (Digital
    Versatile Disks)

47
Diskettes
  • A diskette or floppy disk stores data and
    programs as magnetised spots
  • The disk is contained in a plastic case to
    protect it
  • Diskettes are sometimes called floppy because
    the disk within the envelope or case is flexible,
    not rigid.

48
Zip Disk/Zip Drive
  • A removable disk, capacity of 100 - 250 MB
  • Can be internal or external
  • Popular for keeping backups and for
    transferring large files between computers

49
Electronic Commerce
  • E-Commerce a generic term for all forms of
    business
  • transactions on the Internet. The potential to
    advertise and sell ones product via a web site
    to mass audiences has limitless appeal.
  • The 7 most popular buys on-line are Books, CDs,
    Travel, Music, Electronics, Computer hardware and
    Clothing. Books sales on-line phenomenal growth
    eg. Amazon.com. CDs from America half the local
    price however, delivery cost must be considered.
  • lastminute.com specialise not only in cheap
    travel but also in occasional purchases like cars
    or mobile phones.
  • Shopping on-line using a credit card is
    relatively safe. It is advisable to use
    e-commerce sites that keep your card details on a
    secure server so you dont have to send them each
    time you make a purchase. Ensure that your
    browser is set up for secure connections to the
    internet. A padlock displaying on the status bar
    of the program when you connect to a secure
    server indicates that your data is secure.

50
Requirements for connecting a Computer to the
internet
  • A computer with a fast processor, 16-128MB of
    RAM, up to 100MB of free hard disk.
  • A Modem (unless broadband is available)
  • A Telephone line
  • An Internet Service Provider (ISP). Modem via the
    telephone line will link to the internet through
    the computer system of the service provider.
  • Connection Software

51
  • Data Protection Act 1984
  • Safeguard the privacy of the individual
  • Legislation protects personal data handled in
    computers
  • Aim to control the immense potential for misuse
    of information that arises when personal data is
    stored in computers.
  • - Once data has been transcribed from paper
    files into a form that is easily readable and
    accessible by computers, it is an inexpensive and
    easy task for the data to be extracted from one
    record and correlated with personal data
    concerning the same person from another file -
    infringement of privacy.

52
  • Requirements of organisations that maintain
  • personal records on computers
  • To declare and/or register the use for which data
    is stored
  • Must make information available to those
    authorised to receive without undue delay or
    inefficiency
  • Provide the data subject with a right of access
    to data concerning himself on their computer
  • Keep information secret from those not so
    authorised in such a way that the cost of
    unauthorised disclosure would exceed the value of
    the information to the illegitimate recipient.
  • Maintain a prescribed minimum level of electronic
    and physical security in their computer
    installations - System may involve physical
    security (safes, locks entry cards) for access to
    disks and passwords and also the technique of
    cryptography and authentication.
  • Not to transmit personal data to any organisation
    that does not have similar controls over misuse
    of data
  • The OECDS has also drafted a convention of
    similar effects

53
Repetitive strain injury (RSI)
  • Also known as repetitive motion injury and
    cumulative trauma disorder is
  • the name given to a number of injuries resulting
    from fast, repetitive work
  • RSI causes neck, wrist, hand, and arm pain.
  • RSI problems can result from prolonged computer
    keyboard use
  • An RSI called carpal tunnel syndrome is
    particularly common among young people who use
    computers and certain types of scanners
    intensively. This syndrome involves damage to
    nerves and tendons in the hands.

54
  • RSI Causes
  • Repetition and duration Prolonged, constant and
  • repetitious movements such as typing irritate
  • tendons and nerve casings, causing them to
    swell.
  • Force The harder you hit the keys, the more
    likely to suffer injury.
  • Joint angle Flexing raising, or twisting hands
    to reach the keys constricts the carpal tunnel.
  • Prolonged constrained posture Holding any
    position without moving puts excessive strain on
    muscles and tendons.
  • Left untreated, this syndrome can cause atrophied
    nerve damage.
  • To avoid RSI
  • Frequent short rest breaks.
  • Plenty of sleep and exercise, maintain
    appropriate weight, sit up straight and learn
    stress- management techniques.

55
Health and Safety Computer work environment
  • Prolonged use of computers can cause
    eyestrain,muscular strain, changes in colour
    perception, back and neck pain,stomach aches, and
    nausea.
  • To reduce such physical problems,time spent at a
    VDU be reduced to a maximum of two hours per day
    of continuous screen work.
  • Periodic rest breaks be granted.
  • Steps taken to reduce or alleviate glare produced
    by overhead fluorescent lighting-glare reduction
    screens should be available as required by the
    employee.

56
Systems Development
  • Process by which a computerised information
    system is created
  • Stage 1 choosing the information system to be
    computerised
  • Stage 2 Feasibility study
  • Stage 3 Full analysis of the system to be
    computerised
  • Stage 4 Designing how the computerised system
    will work
  • Stage 5 Writing the programs
  • Stage 6 Implementing the new system
  • Stage 7 Maintaining the System

57
Computer networks
  • Connecting a computer to other computers in same
    building or in another part of the world
  • Share Hardware eg. Printers
  • File - Sharing
  • E-mail / Data exchange

58
  • Computer Based Training (CBT)
  • Advantages
  • Flexibility of studying whenever
  • Can work at own pace
  • Disadvantages
  • No regular routine
  • Student needs to be strongly motivated or highly
    disciplined
  • Cannot consult a tutor
  • No interaction with other students

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  • Multimedia
  • Global term for the developing computer
    technology that
  • can combine text, graphics, hi-fi sound,
    animation, and
  • full motion video in a single high-resolution
    display
  • Made possible by the common use of digital
    recording of text,
  • graphics, sound, and video, coupled with the
    increased
  • processor speeds required to handle large video
    files
  • Multimedia Applications
  • Training Cheaper alternative to traditional
    techniques for staff induction, training in new
    procedures and general management training
  • Architectural Visualisations CAD system
  • Advertising/promotions Logos, trademarks, and
    storyboard outlining Advertising can be created,
    animated, and given a sound track using
    multimedia authoring software
  • Home Entertainment include interactive cartoons,
    games, and an interactive multimedia world atlas

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E-MAIL
  • Disadvantages
  • Carries of viruses
  • Unsolicited e-mails Spam
  • Advantages
  • Quick inexpensive immediate contact can be made
  • Using the cc or bcc facility numerous
    communications can be distributed simultaneously
  • Attachment facility provides the means of
    forwarding long files

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  • Viruses
  • A virus is a program code written to replicate
  • by attaching copies of itself to other objects
    within the system, normally also having a
    detrimental effect. Usually lie dormant for a
    while, then establish their presence by
    displaying a message, stopping the computer or
    deleting a file.
  • These destructive programs infect a computer
    similar to the way biological viruses infect
    people.
  • Problems may range from displaying messages
    through loss of service to corruption or complete
    destruction of data
  • A program virus will seek out and copy itself
    into other program files whenever a previously
    infected program is run.

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  • Virus Protection
  • To protect, purchase your software only from
    reputable dealers
  • Run an anti-virus utility and back up hard drive
  • Greatest carriers of viruses are disks which are
    illegally copied programs, especially games
  • Backup
  • A copy you make of a file in case the original
    file gets destroyed or corrupted
  • Use backup command of your computer
  • Can back up files to floppy disks, a tape drive
    etc

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Precautions and power failure
  • Use special anti-power surge extension leads on
    all computer sockets
  • Use UPS (Un-interruptible Power Supply)
  • Have backup of files
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