Fundementals of Information Technology

(Intro)

What is Information???

Opinion

Science

Knowledge

Going to the cinema;Hours

Tranportation

Costs

Films

Possible Seats????

How can we learn them?Newspapers

Magazines

Asking to someone else

Internet

Phone …..etc.

Information technology is...IT refers to the role of technology in gathering and

using information

Information is an increasingly important resource for businesses and individuals

Computer and communications technologies are more powerful, flexible and cheaper than ever before

How can we learn them?NewspapersMagazinesThink that we don’t know how to read-write?InternetThink that we don’t know how to use computers?Asking to someone elsePhone …..etc.Think that we don’t know the speaken language?

IT is;

All the technologies that we talked about and all the knowledge to use them.

The main purpose is to know much to make better decisions.

Information systems - examplesThe spreadsheet I use to record BİL158 marks

An expert system used to diagnose car faults

An executive information system that summarises the state of the business and compares with competitors

A supermarket’s stock control system

Information systems System (usually computerised) that helps an organisation

carry out its tasks and achieve its goals

An Information System is a set of interrated parts that work together to produce, distribute, and use information products.

Components:– hardware– software– data / information– people– procedures

What computers doA computer has just four basic operations:

receive data as input from the outside world process this data output useful information to the outside world store data and information for further use

It processes raw data to make useful information. But it can perform these operations very fast, accurately and reliably, and can store huge amounts of information

HardwareHardware consists of:

input devices output devices processing (the CPU

and main memory) storage communications

hardware

SoftwareSoftware (programs) is what makes the

computer a general purpose tool - changing the software changes the function

Applications software - useful to the usereg. Word XP, games, a payroll system

Systems software - needed to ‘run’ the computereg. Windows XP, Macintosh OS, anti-virus programs

People - the most important part of an information system

Customers - ultimate users of the information system

Workers and managers - use the information system to carry out their tasks

Systems personnel - ensure the system runs effectively on a day-to-day basis

Systems analysts/programmers - design and develop the information system

End user developers

Evolution of computers and communication technology

Institutional computing era (1950- ) large expensive systems for basic organisational

tasks

Personal computing era (1975- ) small, cheap desktop computers for personal use

Today - interpersonal computing (1995- ) networks of interconnected computers, the Internet

and World Wide Web

Categories of computersMainframes and supercomputers

large organisations: banks, airlines etc powerful ‘number crunching’ for research many users, connected via terminals enabling

‘timesharing’ servers provide software and other resources to

networked computers Hence ‘enterprise’ server

Categories of computers

Personal computers and workstations

• single user, for personal productivity• often networked• Workstations may be used as mid-range servers

Categories of computers

Portable computers laptops, notebooks, personal digital assistants

(PDAs) in the form of palmtop and handheld computers

Embedded computers cars, microwave ovens, etc; sensors and control

systems are single-purpose, not general purpose

Trends - hardwareFaster, smaller, more powerful processors

More direct, easier to use input and output devices

Larger storage capacity

Faster, wider bandwidth communications media to transmit more information

Linking computers together in networks - local area networks, wide area networks, the Internet

Trends - softwareEasy to use software, integration of different tools

Multimedia is widespread

System development is moving from the hands of the professionals to the end user

Use of artificial intelligence

Trends - socialthe threat to personal privacy

the hazards of high-tech crime and the difficulty of keeping data secure

the difficulty of defining and protecting intellectual property

the risks of failure of computer systems

the dangers of dependence on complex technology

Computer HardwareParts of a computer system

COMPUTER FACTS

A computer is an electronic device which works within a binary digital system and has 4 functions: Accept input (data – isolated facts) Process input (data) Produce output (information – processed data) Storage

Tower CPU

RAM

BUS Hard Drive

Floppy CD

Drive Drive

Ports

printermouse

Monitor

keyboard

Peripheral

devices

System unit (box)We call this box by

several names: Computer Tower Desktop

This box contains: CPU Drives System board Slots Interface cards Power Supply Ribbons, connections,

etc.

Computer (System Unit)

Switch

Reset Button

The Back of a ComputerThis is where devices

are “plugged” into the computer:

mousekeyboardprinter internet connectionmonitoretc.

Front Panel

The front has been removed to show:

switches floppyCD drive

Power SupplyThe power supply

reduces house current to smaller voltages (5 and 12 V.)

Notice the many wires protruding from the back of the power supply

These wires provide current for the various parts of the computer

Inside the Computer

System Board

Also called the mainboard

Has slots for cards, rams and cpu.

Devices are connected to mainboard

With the ways on it transfer data from one place to another.

CPU (Central Processing Unit)

Controls the systemPerforms mathematical

operationsLogic is performed hereHas a cooling fan attached

cause temperature is important

Memory...

ROM (Read Only Memory) PROM EPROM EEPROM

RAM(Random Access Memory) DRAM SRAM

ROM(Read Only Memory)

Programs written once and can be read many(Power source is NOT important)

Holds BIOS programmePROM (Programmable chip with a

programming device)EPROM(Can be programmed with light)EEPROM(Programmed by power source)

RAMRandom Access Memory

Storage Units

BIT= smallest unit of storage

binary digit; 1 or a 0

= 8 bits

KILOBYTE

MEGABYTE

GIGABYTE

TERABYTE

BYTE

= 1,000 bytes

= 1,000,000 bytes

= 1,000,000,000

bytes

= 1,000,000,000,000 bytes

RAM FACTS

Holds data and instructions waiting for processing by the CPU

Temporary storageContents are deleted when power source

removed.

DRAM

Is used memory in the computersEDODRAMSDRAMDDRRAM are the kinds...

SRAM

Main difference from DRAM is no need to update the data

Included in CPU nowadaysCosts more than DRAMSo it is used for cache

CACHE

Cache is fast accessing intermediate memory that holds the most needed data and instructions.

It is smaller than RAM.Because it is smaller than RAM a search of cache

is faster memory access.Therefore it is always searched first when

available.

CPU

CACHE

RAM

HDD

How does the data flow?

Chips and Interface Cards

All secondary storage has 2 parts:

A disk – a platter which stores the data/inforamtion

A drive – mechanism which reads the disk

NOTE: a read/write head is part of the drive which sits over the disk and read the data

Hard Drive

All Disks have two parts:

SECTORS TRACKS

All Disks have two parts:

This makes an

Addressable

Space.

Therefore,

Disks are

Randomly

Accessible.

Hard Drives

Composed of several disks.

Very large, permanent storage.

Not portable storage.

Disks are magnetic.

Floppy Drive (3 1/2”)

Floppy Drives

Composed of one disk.

Small storage.(Max. 1,44 MB)

Portable storage.

Disks are magnetic.

CD Drive

CD Drives

Composed of one disk.

Large, permanent storage.(=~¨700 MB)

Portable storage.

Disks work with light waves.

DVD Drives

All the specifications are same with the CD Drives but they can store larger data than CD technology (up to 12 GB or more...)

Video Card

•By video cards datas in computers can be seen on monitors...

•Has a memory in.

•Can be PCI or AGP

Monitor

•Are used to display data in Graphical User Interface

•Monitors has dots to show the data. They are called pixels.

•Pixels must be closer to see detailed...

Communication Devices Devices that allow users separated

by distance and time to exchange documents, files, graphics, and other digital information.

Keyboard

Mouse

Ink Jet Printer

Dot Matrix Printer

Laser Printer

Software

According to the American Heritage Dictionary software is

"The programs, routines, and symbolic languages that control the functioning of the hardware and direct its operation."

Software

In other words, software instructs the hardware what to do, and uses the hardware to perform specific tasks.

Such as display information on a screen, format a floppy disk, etc. There are 2 main types of software

What are the types...

Types of Software

Operating systems a set of programs that manage the computer

(e.g. loads & controls the execution of other programs, manages the storage of data on disks)

Types of Software

Applications Software: Programs written for specific purposes in order

to perform functions specified by end users.

Operating Systems

Operating SystemsMS-DOS (Microsoft Disk Operating

System), also known as PC-DOS (Personal Computer Disk Operating System), is the standard OS on Intel-based

microcomputers, and is often referred to simply as DOS.

Operating Systems

MS Windows (Microsoft Windows): a GUI (Graphical User Interface) that works

with DOS to provide a more user-friendly and powerful interface to the computer and its' applications.

current versions of MS Windows (including 3.11) are not true operating systems, and require DOS to be installed on the computer before function.

Operating Systems

Windows NT & Windows 95 & Windows 98, 2000 and XP are true operating systems (i.e.. they do not require DOS) which have a GUI superior to MS Windows.

Operating Systems

Windows XP and 2000 are the latest version of Windows from Microsoft, intend to replace Windows 95, DOS, and MS

Windows as the operating system of the future for home uses.

Operating Systems

Given the rapid change of hardware technology DOS and Windows are dying rapidly.

New systems come with a newer version of OS installed automatically.

Usually have a choice of one of: Windows NT, Windows 95, or Windows 98, 2000 and XP.

Operating Systems

The Macintosh operating system is used on Apple computers, and was the first GUI-based operating system.

Has always been the easiest to learn/use operating system,

But has been limited to the proprietary Apple hardware, and therefore not as popular as DOS and Windows.

Operating Systems

OS/2 was the first advanced GUI operating system for Intel-based microcomputers, and has been around for a few years.

Originally a joint project with IBM and Microsoft, OS/2 is now maintained by IBM, and was a competitive product to the various MS Windows programs.

Operating systems

Such as network servers, and certain business applications.

OS/2 is used heavily in the Banking industry. You probably use OS/2 when getting money from an ATM machine.

Operating Systems

UNIX is an operating system has been most popular on workstations and

other high-end computer systems. various flavours of UNIX, such as AIX (the

version used on Juliet), NeXTStep, and Solaris, which tend to be developed for specific vendor hardware platforms.

Operating Systems

Linux: UNIX-like operating system : developed firstly by a student from Finland works on a wide variety of vendor systems,

including Intel microcomputers.

UNIX is a very powerful and rich operating system, but also very difficult to master.

Applications Software

Word Processing Software for creating standard text documents,

such as reports, books, etc. examples are Microsoft Word, WordPerfect,

and Write.

Applications Software

Word processors are distinguished from the simpler text editors, by the inclusion of more advanced features (word

wrap, headers & footers, etc.), and more complex proprietary data formats. Text

editors have limited functionally.

Application Software

Desktop publishing software: more sophisticated programs for creating large

documents (e.g. books), or documents with a lot of graphic (newsletters, brochures, etc.)

examples are Pagemaker and Ventura.

Application Software

Spreadsheets Software for working with numeric data,

calculations and graphing/charting. examples:

• Microsoft Excel;

• Lotus 1-2-3, and

• Quattro Pro.

Application Software

Databases allows the creation of highly structured

containers for storing information about things. examples: Microsoft Access, Paradox, and

Oracle. examples of types of database systems would

be inventory systems, or bank accounts.

Application Software

Databases describe the characteristics of things (e.g. name, address

and phone number for a mailing list), and allow the user to input values for storage, and

retrieve them at a later date.

Application Software

Communications allows one computer to communicate with

another. Examples are Procomm and Kermit.

Communications software often uses a modem to provide the communications link with another computer system.

Application Software

Graphics allows the user to create or edit images, such as

• line art;

• photographs, or

• drawings. examples are Corel Draw, Morph and Adobe

Photoshop.

Application Software

Presentation/Multimedia allows the user to combine various data

formats (text, images, audio, video) to create products like business presentations, educational programs, games, etc.

examples are Microsoft Powerpoint and Macromedia Director.

Application Software

Programming used to create other software programs. examples are Visual Basic and Borland C++.

Application Software

Utilities performs a variety of functions for maintaining

and administering other software programs, data files, and hardware.

examples are PCtools and Norton Utilities.

Application Software

Games & Edutainment - Games are, well, games.

Edutainment software a new term used to describe software that uses a

game-like environment to teach about specific topics.

Application Software

Viruses special software programs that can "infect"

other software

Application Software

Industrial - Specialized software programs used to control machines or devices

such as:• photocopiers;

• robotics;

• cars;

• space shuttles;

• etc.

And software types can be change by the legal usage...

Public Domains : everyone can use limitless and no payment is needed...

Sharewares : Everyone can use for a limited time and if want to use afterwards payment is needed...

LAN/WAN

Networks

NETWORKEach computer has its own Operating System

The Client Server Model

NETWORK

SERVERCLIENT

Client to server: request for service

Server to client: response

Server running Unix, NT or some similar OS

Ethernet Hub

PC

PC

Serial Line Interface

Router

WAN link

Ethernet Interface

Network Hardware

Ethernet Interface

Router

WAN link

A Wide Area Network S

erver

Server

Server

Server

PC

PC

PCPC

Typically a multi-city network

LAN Is Limited To...

Most LAN networks are confined to a single building or group of buildings.

A LAN can be connected to other LAN’s via a telephone.

Definitions

Ethernet:Developed by Xerox Corporation with DEC and Intel.Transfer rate of 10 MBPS. Fast Ethernet can handle up to 1Gbps.

Apple talk:Inexpensive local area network build in to all apple MAC. computers . Supports apples local talk,and Ethernet,as well as IBM's token ring

LAN vs. WAN

LAN:Local Area Network.

Used for short distances. Such as buildings and groups of buildings.

Can be used for work groups.

WAN:Wide Area Network.

Used for long geographical areas like countries and the world.

The world wide web.

Wide Area Networks can be used to interconnect LANs

LAN

LAN

LANR R

R

Wireless

PDAs Palm Pilot, MS CE

Mobile phonesWireless LANCDPD (Cellular Digital Packet Data)

This is a direct digital cellular service Follows closely the OSI model E,I,A Interfaces

Telephone Wires and Modems...

We use modems to convert the digital data to analog data to use telephone lines by transportation.

Dial-up modems can transfer 56 Kbps max.Firms are trying to use ISDN(Integrated

Service Digital Network)DSL(Digital Subscriber Line) is more faster

than Dial-up.

Telephone Wires and Modems...

ADSL is a form of DSL. It uses the spare frequency of the copper

telephone wires.So communication of the computers are

faster and the other frequency can be used for phone calls.

ADSL speed changes 64 Mbps to 2048 Mbps for the Internet...

What is the Internet?It is the unique global network connecting

individual networks which may use different protocols internally. A gateway connects the individual network to the Internet, doing the necessary protocol translation.

It is the special case of an “internet” which is a network of networks. The inter-connection uses TCP/IP.

TCP/IP

Internet Protocol is like the phone number of a computer on a network. Must have one to talk with others.

Transfer Control Protocol helps the computer to sent and get files more than bandwith can transport in once...

By the protocol files can divided into parts and at the other side the protocol makes them connect...

Computer VirusA computer program usually hidden within

another seemingly harmless program.

It produces copies of itself and inserts them into other programs.

A computer virus usually performs a malicious action, such as destroying data.

7-10 new viruses are found every day.

Effects of Computer Viruses

It can destroy data and programs in computers.

It effects any computer that opens the seemingly harmless program.

It makes the computer crash

Sometimes it can destroy the hardware of the computer

Examples of Viruses

The Klez virus.

My party virus.

Klez virus This first appeared in April 2002.

The message usually appears to be from someone you know.

The message may say the attachment is an anti-virus tool or a new game.

Subject field can vary.

May show in subject field as “Hi” or “Hello” or “How are you?”.

My party virus

First appeared in January 2002.The subject lines may vary.Usually along the lines of “New photos

from my party”. The note will tell you that there are

pictures attached in order to get you to open the attachment.

Attachment may look like a website address and not an attachment.

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Boot-sector infectors Attach to the “boot sector” of a disk Virus activated whenever computer reboots

Macro viruses Attach to documents and spreadsheets When user opens documents, virus spreads to

word processing programs

Types of Viruses File infectors

Attach themselves to programs on infected computers Virus runs when user runs a program

Other Malicious ProgramsTrojan Horses

Involves human interaction Users run the program intentionally, but it does something more than user

thought it would Not a virus for it does not spread on it’s own, but does have virus-like effects

Example:

A friend sends you a game he/she found on the Internet. You run the game, finding it rather fun. However, without your knowledge, part of the program is searching your hard drive for password files. Your password files are sent to the person who originally wrote the program, leaving your system and identity vulnerable to potential damage.

Other Malicious Programs

Worms Involves no direct human interaction Like a virus, but spreads from computer to computer via a network

Example:

Your computer has fallen victim to the Code Red Worm. How did this happen?

An Internet Information Server (IIS), often running by default in many Windows operating systems & known for its vulnerabilities, served as the Code Red worm transmitter. Through the Internet, the Code Red actively sought computers running the IIS. Many users were unaware the IIS program was operating on their computer, thus infection by the Code Red worm.

How Much Damage? Benign Viruses

Annoying, but not seriousExample:

You attempt to shut down your computer, and the message “Parity Check” is displayed. This is the only effect of a benign virus, the Parity Check.

Malignant Viruses Serious viruses Cause great damage that may or may not be repairableExample:

CIH Virus activates on 26th of each month. It overwrites most of data on infected hard drive and Flash BIOS. The BIOS software, located in the motherboard, tells computer to boot. No BIOS, no booting!

Common Ways Viruses Spread

Email attachmentsShared filesFloppy disks Infected documents and infected word processors

Important: Viruses almost never spread between operating systems such as Mac

and Windows!

Ways to Prevent Viruses Install a virus scanner

Many are free Keep it updated Program it to run automatically A few examples

• Norton• Panda• Mcafee

Do not run programs found randomly on the Internet If you use Microsoft Word or Excel, disable macros

Prevention (continued)

Only open expected email attachments Do not open anything from people you do not know If you are not expecting it, even from someone you know,

do not open it! Disable auto-run features in email programs Use Virus Scanner before opening downloaded Internet

files Keep your operating system and programs up-to-date Turn off scripting in your web browser

How Do I Know If I Have a Virus?

Some typical symptoms that may indicate a virus infection include:

Virus checker gives a detected virus warning Strange messages appear Computer crashes more frequently Strange files you do not recognize start appearing Files get bigger or disk space disappears for no apparent

reason Programs stop working as expected

I Think I Have a Virus!

Stop using the computerWrite down any strange messages or warningsDo not reboot, open files, or run programsRun your virus scannerSeek tech support help

How to protect yourself

Do not open any e-mails that are sent from someone you don’t know.

Especially do not open any e-mail attachments.

Install anti-virus software into your computer and keep it updated.

Scan any documents you receive with your anti-virus software.

Make everyone you know aware of any viruses.