Computer Skills

Chapter 1- Principles of Computer Technology

Computer GenerationsFirst 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.

Lesson 1

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

Input Device

Output Device

Central Processing Unit

Hardware Components

Keyboard

Mouse

Scanner

Printer

Screen

Headsets

Control Unit

Registers

ALU

Storage Device

HardDisk

RAM

Floppy Disk

CD-Rom

Main Storage

Secondary Storage

Flash DIsk

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

Software Programs Types

Lesson 2

Types of Software Programs

Operating System- OS

Applications Programs

WindowsDOSUnixLunix

Utility ProgramMs Office

Graphics Program

Programming Lang

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 / ServerComputers 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 InternetCollection 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 (1)

• The ExtranetAllowing 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

The Internet (2)

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-GovermentIn 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, etc2. Hospitals : maintain patients records, performing surgeries. etc3. Education : distance learning

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.

Security

Publishing and CopyrightsThe 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

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

Computer Viruses (2)