Transcript Chapter 1-1 - KSU Faculty Member websites

European Computer Driving
Licence
Module 1 – Concepts of IT
Section 1: General Concepts
This presentation is an open source material on web,
some modification made by: Sumayah Abu-Dawood
The original source found on: http://www.pearsonschoolsandfecolleges.co.uk/FEAndVocational/ITAndOfficeTechnology/ECDL/PGECDL/FreeResources
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General Concepts
Z Information Technology (IT)
,
General term used to describe
the use of computers to process
and transfer information.
,
Can also refer to other office
equipment (such as faxes and
telephones) which contain tiny
computers
2
Hardware and Software
Z Hardware (HW)
,
Refers to the physical
parts of a computer –
those parts which you
can see or touch.
Z Software (SW)
,
Primarily a list of instructions coded in
a special way that computers can
understand.
• Operating system software – e.g.
Windows which works in the
background and controls your software
and hardware devices
• Applications software – e.g. Microsoft
Word – software used to perform tasks
3
main parts of computer system
Z Monitor (VDU) visual Display
Unit: to display results of
processing.
Z System Unit : this contains all
the basic computer components
that do all the hard work
Z Keyboard: to enable text and
commands to be input into the
computer
Z Mouse: to enable the user to
point and click at pictures and
menus
4
Different Types Of Computer
Z
Z
Z
Z
Z
Personal Computers (PC).
Laptop/Notebook Computers.
Mainframe Computers.
Networked Computers.
Personal Digital Assistants (PDA )/ Handheld Computers.
5
Personal Computers (PC)
Z An essential tool for managers,
humble office workers and
home users
Z Two main types:
,
,
Z Hardware devices (screen,
keyboard and mouse) attached
to the system unit (by a cable)
are called peripheral devices
Desktop model – the system
unit sits horizontally on a desk
and the monitor is placed on top
Tower model – the system unit
is vertical so can be placed on
the floor to save desk space
6
Notebook/Laptop Computers
Z Similar in specification to a
personal computer
Z Monitor and keyboard are
integrated into a single unit
Z Can be used from the mains or
with a built-in rechargeable
battery
Z More expensive than personal
computers due to
miniaturisation of computer
components
Z Ideal computer for business
people and ICT trainers who are
constantly on the move
7
Mainframe Computers
Z Large, fast and expensive
Z Users connect via
terminals which are
Z Used by large organisations
located in different cities or
such as utility companies,
even abroad.
banks or multinational
, Dumb terminals – these types
companies.
of terminals cannot be used
Z Connect hundreds or
unless they are connected to
the mainframe
thousands of users.
,
Intelligent terminals – e.g. a
personal computer connected to
a mainframe, can also be used
when not connected to the
mainframe
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Mainframe Computers
Paris
Dublin
London
New York
Mainframe
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Networked Computers
Z Personal computers can
operate as stand alone
computers or they can be
connected together as
networked computer.
Z Many networks use a
server , which is a
computer that controls
access to HW, SW and
other resources on a
network.
Z Personal computers
connected to a server via
network cards and cables
Z The software and data is
stored on the central
server rather than installed
individually on each PC
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Networked Computers
Z The network also enables a
fast Internet connection,
printers and scanners to be
shared.
Z Users access allocated
resources via a user name
and password.
Z Very popular with small-tomedium-sized businesses,
schools and colleges/adult
education centres.
Server
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PDAs/Handheld Computers
Z Handheld computer is a
computer small enough to
fit in one hand.
Z Some use a stylus which
you use to write or draw on
the screen.
Z Run very basic cut-down
software such as
calculator, address book
and notepad functions
Z Can be connected to a PC
to synchronise data.
Z PDAs can also be used as
mobile phones and can
access the Web to send
and receive emails.
stylus
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Computer Components
Computer
Hardware
Software
Any physical part that
you can see and touch.
Programs that allow you
to use computer but you
can not see or touch.
Pass ECDL4
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Hardware Components
CPU
Memory
Storage
Devices
Hardware
Input Unit
Computer
Output Unit
Operating
System
Software
Application
Pass ECDL4
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Central Processing Unit (CPU)
Z The main brain of the computer that
performs the work and controls the
transfer of information.
Z The speed at which CPU can process
information is known as clock speed.
Z Speed is measured in Megahertz or
Gigahertz.
,
,
Megahertz (MHz)= 10 6 (1 million cycle per
second).
Gigahertz (GHz): 10 9 (1 billion cycle per
second).
Z When CPU is on one chip, this is a
microprocessor.
Z Examples: Intel, AMD.
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Computer Memory
Memory is a chip that holds data waiting to be processed & instruction
waiting to be executed.
There are two kinds of memory:
Z RAM (Random Access
Memory):
,
,
,
,
,
Store information temporary.
CPU transfers information from the
hard disk drive to RAM.
The more you have installed, the
faster your computer will work.
When the computer is switched off,
anything stored in RAM is lost
Volatile memory
Z ROM (Read Only Memory):
,
,
,
,
,
,
Store information permanently .
Used to store important information that
the CPU needs to keep the PC running.
ROM can only be accessed by the CPU
and cannot be changed.
The information doesn't lose its content
when power is switched off.
Information stored in ROM can be used
repeatedly
Nonvolatile memory.
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Computer Memory
RAM
Main memory
Volatile memory
ROM
Secondary memory
nonVolatile memory
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How RAM is work???
Z Switch on the computer
,
,
The processor transfers
operating system
software from the hard
disk drive to RAM.
The Windows desktop
appears.
Z Double-click on the
Word icon.
,
The processor transfers
the software from the
hard disk drive to RAM.
Z Open a Word document
,
The processor transfers
the file information into
RAM so you can see it
and make changes to it.
Z If you don’t SAVE the
document, the changes
will be lost when you
switch off the computer!
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How ROM is work???
Z Switch on your computer.
Z (POST) and boot-up are
carried out to make sure your
CPU, memory chips and
other components are
working:
,
,
If not, then an error message
will appear on screen.
Z The PC start-up software is
stored in ROM so it can be
used time and time again.
If they are, then information
is transferred to RAM to start
up your operating software.
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How memory is measured
byte
Z RAM is divided into millions of
units called Bytes.
Z Each byte contains 8 bits, which
represent s one character
(A,@,6,....).
Z Memory sizes :It’s the number of
bytes the chip or devices has
available for storage
Z 1 kilobyte (KB) =1024 bytes
Z 1 megabyte (MB) =1024 KB
Z 1 gigabyte (GB) =1024 MB
Z 1 terabyte (TB) =1024 GB
RAM
00110100
E
8 bits represent
(4)
:
:
:
One BYTE
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File Sizes
Z A simple Word document will
measure approx 20Kb
Z A 12 page report with
pictures will take up much
more space – maybe 300Kb
Z A 100 page user manual with
photos and screenshots
could be at least 2Mb in size
Z Microsoft Excel, for example,
takes up approx. 6Mb of hard
disk space
6000
5000
4000
3000
2000
1000
0
Text
document
12 page
report
100 page
manual
Microsoft
Excel
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Input devices
Z These are devices used to put data into the computer
Keyboard
Light pen
Mouse
Scanner
(OCR)
Trackball
Joystick
Microphone
(Voice Recognition)
Digital camera
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Output Devices
Monitors (VDU)
Z Come in 15”, 17”, 19”, 21”
screen sizes.
,
,
Picture is made up of
millions of dots called pixels
Picture quality depends on
number of pixels going
across and down the screen
Z Resolutions
,
,
,
Resolution is the number of
horizontal and vertical pixels
in a display device.
800 x 600 is typical of a 15”
screen
1600 x 1200 is typical of
larger screens
Z Two different types
,
,
CRT monitors – similar to a
TV screen
TFT monitors – much more
slim line
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Monitors
24
Monitors
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Output Devices - Printers
Z Inkjet printers
,
,
,
Mainly used by home users
Black and white or colour
printing
Medium in quality and cost.
Z Laser printers
,
,
,
Used in most offices.
Black and white or colour print
High price but suitable for large
number of prints.
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Output Devices - Printers
Z Dot matrix printers
,
,
Very noisy and low print
quality.
Low cost , use to print invoice,
schedule, appointments.
Z Plotter
,
Used mainly by architects to
produce high quality prints such
as: building plans, posters.
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Output Devices
Z Speakers:
,
,
Connect to a soundcard
supplied with multimedia PCs
that acts as (stereo).
Speech synthesiser: program
is able to transfer written text
into audible speech.
28
Input/Output Devices
Z Touch screen
,
,
Allows the user to touch an
area of the screen rather than
typing from a keyboard
Used mainly in tourist offices,
bus information kiosks and Job
Centres
Z Modem
,
Use to transfer telephone signal
to digital or vs..
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Storage Devices
Z Is the physical material on which
a computer keeps data,
instructions and information.
Z There are 2 types of devices
storage :
- Magnetic Disks :Use magnetic particles to
store items on a disk’s surface. Three type of
magnetic disks are Hard disks ,Floppy disks and
Zip disks
-
Optical Disks
Optical discs store items by using microscopic
pits ( indentations) and lands (flat areas) that
are in the middle layer of the disc.
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Storage Devices
Z Hard disk drive HDD– this
stores all your programs and
data.
Z HDD stores huge amount of
data, the capacity is
measured by GB, the speed
of HDD is called access
time.
Access time is the time
required by HDD to search and
retrieve data.
Access time is measured by
millisecond (msec)
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Other Storage Devices
Z
Floppy disk drive – this stores
smaller files.
Z Zip Drive
,
,
Uses zip disks which can store
either 100Mb or 250Mb of data
Can be internal or can plug into
a PC’s USB port
Z Flash Drives
,
,
Plug into a USB port
Typical storage – 28Mb,
256Mb, 512Mb,1GB-32GB.
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Note
Z Data is saved as magnetized dots on
Magnetic storage medium.
Z Storage surfaces is divided into : Track an
Sector.
Z Formatting: the process of preparing
storage disk for use, it creates Tracks and
Sectors.
Z When you format your disk, all data is
erased and the disk will be as “ anew” one.
Pass ECDL4
Track
Sector
33
Storage Devices
Z There are many different
formats of optical discs exist
today. CDs and DVDs
Z DVDs having a much greater
storage capacity than CDs.
34
Storage Devices
,
,
CD –ROM : software and
games are normally supplied
on CD ROM disks.
Information is read-only and
cannot be changed.
capacity : 650MB (75 min of
music).
CR-R (Recordable): user
can store data once .
CD-ROM
CD-R
CD-RW
,
,
,
CD-RW (Re-Writable):
allow user to save data
many times.
DVD ROM drive – these can
be used to watch films etc.
DVD-R (Recordable): used
to save data once.
capacity: 4.7GB (120 min
video).
DVD
DVD-R
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The System Unit
Z System Unit is a case that
contains electronic components
of the computer
Z It can be a tower case or
desktop case.
Z The main circuit board of the
system unit is the motherboard.
Z motherboard contains complex
electronic circuits and silicon
chips.
Z All the computer components
plug into the motherboard either
directly into slots or by cables.
36
The System Unit
CD-ROM Drive:
Read information and write
on CD, read from DVD.
Floppy disk drive:
Read and write information
From floppy disk.
On/ Off
switch
37
The System Unit
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Removable Storage Comparison
Device
Capacity
Floppy disk
1.44Mb
Zip
250Mb
Flash drives
256Mb
CD
650Mb
DVD
4.7Gb
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Computer Performance
Four main factors will determine the Performance of
computer:
,
,
The clock speed of the
CPU (measured in MHz,
GHz).
The capacity of RAM
installed (measured in MB,
GB).
,
,
The capacity and speed of
HDD (Hard Disk Drive).
The number of application
running.
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Software Components
CPU
Memory
Storage
Devices
Hardware
Input Unit
Computer
Output Unit
Operating
System
Software
Application
Pass ECDL4
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Operating System (OS)
Z OS: A special computer
programs that organise
and control a computer.
,
,
,
,
Manages the smooth running of
programs running in RAM by
allocating the required
resources.
Provides an interface so that
the user can communicate with
the computer.
Communicates between
software and hardware devices.
Organises the storage and
retrieval of information.
Pass ECDL4
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The BIOS (Basic Input/Output System)
Z
Z
Z
Z
Z
Z
The most basic software within the PC.
Stored in ROM.
Ensures the hardware operates properly.
Records basic information about the PC.
Usually configured by the manufacturer.
No user intervention is usually required.
Pass ECDL4
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Example of Operating Systems
Z Microsoft Windows:
Windows95, Windows Me,
Windows XP, Windows
Vista.
Z MS-DOS created by
Windows but text-based
Z Macintosh (MacOS) was
created by Apple.
Z Linux is a popular alternative
open-source OS.
Z Unix is another OS used in
companies or universities.
Pass ECDL4
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User interface
Z You interact with software through its user interface.
Z The user interface controls how you enter data and instructions and
how information is displayed on the screen.
Z 2 types of user interfaces are
, Command-line interfaces.
, Graphical user interfaces
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Command-line interfaces
Z User types commands or
presses special keys on the
keyboard to enter data and
instruction.
Z Its difficult to use because they
require exact spelling, grammar
and punctuation
46
Graphical User Interface (GUI)
Z Enables users to click and point at icons and menus on screen,
instead of typing in computer commands
Pass ECDL4
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Keeping Up to date
Service packs:
Z A collection of updates, fixed for your operating system.
Z It contains new drivers for many computer components.
Z Could be supplied on a CD or downloadable from the
internet.
Pass ECDL4
48
What happens when computer
boots up??
Z When computer is switched on, BIOS carries out (POST) –
Power On Self Test and do boot-up operation.
Z Boot-up operation has 2 main functions:
,
,
Ensure that all hardware is running ,CPU and memory are
functioning correctly.
Load the operating system (OS) from HDD to RAM.
Pass ECDL4
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Application Software
Z Application software: is a computer programs
designed for a specific purpose.
Z Application software is separate from the operating
system but must be compatible with it in order to be
able to operate.
Z Each application software is suited for special
purpose…. See following example.
Pass ECDL4
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Examples of Application Software
Application
Example
Use
Word Processor
Microsoft Word
Format text, write letter
Spreadsheet
Microsoft Excel
Organize numbers in tables
and do calculations
Database
Microsoft Access
Stores large data that can be
questioned
Presentation Tools
Microsoft PowerPoint
Design presentation with text,
image, sound, video.
Microsoft Publisher
Design large pager like poster
and catalog
Desktop Publishing
E-mail
Microsoft Outlook Express
View and organize email
Web browsing
Microsoft Internet Explorer
Access information on the
internet.
Graphics
Photoshop/ CorelDraw
Design graphics
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Pass ECDL4
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Problem Solving
Pass ECDL4
53
Common error indicators
Z No display on the screen.
Z Error messages on screen.
Z Flashing lights on printer.
Z No printer output.
Z No mouse cursor.
Z Bleeping sounds from system
unit.
Pass ECDL4
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Resolving problems
Z Basic checks:
,
,
,
Power supplies
External connections
Supplies of consumables
Z Manufacturer support
Z Manuals
Z Windows Help and Support
Centre
Pass ECDL4
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Other considerations
Z Error reporting
Z Automatic System Updates
Z Device drivers
Z Backups
Pass ECDL4
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System Development
System development cycle is a set of activities used to build an
information system.
• Perform by “system analysts”.
Analysis • Meet Project members, set objectives, write specifications.
Programming
• Perform by “programmers”.
• Write the program using programming language.
• Perform though development to correct system “bugs” and faults.
Testing • Next test performs by users who can use the system (Beta testing).
Documentation
• Written the finished system.
• 2 levels: technical operation for future development, user guides.
Pass ECDL4
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