Transcript Computer Skills

Computer Skills
Chapter 1- Principles of Computer
Technology
Lesson 1
Computer Generations
First Generation(1950 – 1959):
• Very big sizes
• Using the vacuum tubes in building computers.
• Necessity to cooling system as a result of generating heat.
• Used by large companies.
Second Generation(1959 – 1965):
• Transistors were used instead of vacuum tubes.
• Minimized size and cost helped small companies to use
computers.
• Start using programming languages like Fortran and COBOL.
Third Generation(1965 – 1975):
• Software packages appeared.
• Using integrated Circuits .
•Computer became smaller size and less expensive.
Fourth Generation(1975 – 1985):
• Micro Computers appeared
• Innovation of electronic technology enable to integrate the
computer components on one electronic board.
• Computer networks start to appear.
Fifth Generation(1985 up till now):
• New technology produced laptops, palms that combines huge
storage capacity with small size .
• Appearance of multimedia and virtual reality.
Types of Computers (1)
1 . Super Computer :
Large size, huge capacity, high speed, ability to link hundreds of
terminals.
Very expensive , only exists in large companies like Saudi Aramco.
2 . Mainframe:
Commonly used at universities, aviation and communication
companies.
Connecting many terminals using time sharing technique.
3. Mini-Computer:
This type of computer has become obsolete as micro computer has
started having huge capacity equal to the minicomputer.
Types of Computers (2)
4. Micro-Computer:
Known as personal computer. Commonly used as a result of the fast
processing capacity and having large memory.
Desktops, Laptops and Pockets or Palm are several forms of it.
5 . Workstation:
More powerful than Micro Computers in processing speed and
storage capacity.
It used by scientists and engineers to perform graphic applications.
6 . Control Computer:
It’s used in realtime applications like train operating stations and
power stations. It has the ability to deal with mistakes or errors
which occur during functioning and repair them.
Computer Main Parts
Hardware Components
Input Device
HardDisk
RAM
CD-Rom
Flash DIsk
Mouse
Scanner
Main Storage
Output Device
Storage Device
Floppy Disk
Keyboard
Secondary
Storage
Central
Processing Unit
Printer
Screen
Headsets
Control Unit
Registers
ALU
Memory Size and Units
•Computer is an electronic machines deals with two modes called
Binary Mode
•Binary mode consists of either 0 or 1.
•1 indicates ( existing ), 0 indicates (not existing)
•All the numbers, letters and symbols represent by a set of 0s and
1s.
•We call 0 or 1 a (bit). Which is the smallest measurement unit used
to measure the capacity of storage devices.
Symbol
Unit
Value
Bit
Bit
1 or 0
Byte
Byte
8 Bits
KB
Kilobyte
1024 byte
MB
Megabyte
1024 KB
GB
Gigabyte
1024 MB
Lesson 2
Types of Software Programs
Software Programs Types
Applications
Programs
Ms Office
Graphics Program
Programming Lang
Operating
System- OS
Windows
DOS
Unix
Lunix
Utility
Program
Computer Networks
Collection of computers connected together with an objective
of sharing the resources.
Networks enable the user to share software by setting a Server
that enables sharing of programs ,files and folders to only
authorized users by entering a valid username and password.
Also, the hardware can be shared like sharing computers and
printers that are connected to the network.
Networks Types:
• Local Area Network (LAN)
•Wide Area Network (WAN)
• Client / Server
Computers are categorized according to usage to :
Client: make use of the services provided by the server.
Server: provides services to the network users and controls
them.
• Types of communication Lines:
• Telephone lines through modem which is connected to the
Internet Service Provider (ISP).
•Integrated Service Digital Network (ISDN)by wires or by
satellites. Digital Subscriber Line(DSL has the advantage of
high speed that might reach 1MB/sec.
•Satellite are devices for receiving and sending data. very
expensive way of communication
The Internet (1)
• The Internet
Collection of various networks that can communicate with each
other. We need a special kind of software called (Internet
Browser ), for example (Internet Explorer) to access all the data
stored on the net.
•The Intranet
An internal and local network depending on a special protocol
for the network called (TCP/IP).
The Internet (2)
• The Extranet
Allowing access to a private network using secure entry
points.
Main Uses of the Internet
• World Wide Web (www)
•Email service
•The service of file transfer ( FTP)
•Chatting
Lesson 3
Using IT in daily life
• Accounting : it follow up the daily ,monthly accounting works.
• Payroll programs : common application in which the database
related to the employees are created and the personal information
is stored.
• Warehouse stores : it includes an observations of the warehouse
main operations as release orders, invoices and making inventory
check.
• Aviation companies: it is used in the process of reservation and
knowing the dates of the available seats on flights, selection of
seats and sorts of meal on flights.
E-Goverment
In order to save effort, time and money, governments started to
encourage the use of computers in implementing a lot of its
services. as an example:
1. The Ministry of Higher Education: registration process, applying
for scholarships, etc
2. Hospitals : maintain patients records, performing surgeries. etc
3. Education : distance learning
Security
Some helpful procedures to perform in order to protect your data
and computer are:
1. Having backup copies on disk or compact disk .
2. Enabling Firewall to avoid hackers from penetrating computer.
3. Username and password: password must contains more than 8
characters. The characters can be small, capital letters mixed with
numbers and symbols.
4. Apply level of accessibility to users.
Publishing and Copyrights
The owners of software have a full right of distributing ,copying and
publishing their works unlike the user who bought a licenses
software , who is not allowed to do so with any software product.
The process of copying the software is penalized by law as its
protected by law of publishing and copyright.
Freeware: free programs protected by the law of copyrights. Those
programs cant be amended or modified or developed within other
programs.
Shareware: programs distributed freely aiming to experiment them
for a limited period of time.
Computer Viruses (1)
Small programs aims to harm the computer system by canceling
some of the main operations, putting them out of order, erasing
and destructing files which are important to the user.
Increase the demand for the Internet and the e-mail helped greatly
in spreading viruses.
How can you be infected by Viruses:
• When you open an infected file on your computer using floppy
disks or flash disks.
• Download insecure files from the Internet
Computer Viruses (2)
How to prevent Viruses:
• Preparing a number of backup copies of the software.
• Avoid download insecure files
• Install antivirus program to scan the computer regularly
• Test the software on an independent computer without being
connected to