Itc lecture

Engr. Haseeb Ahmad Khan

The Parts of a Computer System

Looking Inside the Machine

Software: Bringing the Machine to Life

What is a Computer? ◦ An electronic device, operating under the control of

instructions stored in its own memory, accept data,

process the data according to specified rules, produce

results and store the results for future use

Consists of: ◦ Hardware

◦ Software

◦ Data

◦ Users

What is a Computer? ◦ A computer can convert data into information that is

useful to people

A computer's hardware consists of electronic

devices; the parts you can see and touch.

The term "device" refers to any piece of

hardware used by the computer, such as a: ◦ keyboard

◦ monitor

◦ modem

◦ mouse

◦ etc

Software – also called programs – consists of

organized sets of instructions for controlling the

computer.

Some programs exist for the computer's use, to

help it manage its own tasks and devices.

Other programs exist for the user, and enable the

computer to perform tasks for you, such as

creating documents.

Data consists of raw facts, which the computer

can manipulate and process into information that

is useful to people.

Computerized data is digital, meaning that it has

been reduced to digits, or numbers. The

computer stores and reads all data as numbers.

Although computers use data in digital form,

they convert data into forms that people can

understand, such as text, numerals, sounds, and

images.

Data is collection of unprocessed items, which

can include text, numbers, images, audio and

video

When data are processed, organized, structured

or presented in a given context so as to make

them useful, they are called Information

People are the computer's operators, or users.

Some types of computers can operate without

much intervention from people, but personal

computers are designed specifically for use by

people.

Types of Hardware

The CPU

Memory

How Memory is Measured

Input and Output Devices

Storage Devices

A computer's hardware devices are categorized as

follows: ◦ Processor

◦ Memory

◦ Input and output (I/O) devices

◦ Storage devices

01001010 01101010

01101111 10001111 10000000

Looking Inside the Machine - The CPU

The procedure that

transforms raw data

into useful

information is called

processing. This

function is divided

between the

computer's processor

and memory.

The processor

is also called

the central

processing

unit (CPU). It

manages all

devices and

performs the

actual

processing of

data.

The CPU consists of one or more chips attached to the

computer's main circuit board (the motherboard).

Memory also consists of chips attached to the motherboard.

Memory holds data and program instructions as the CPU works with them. This memory is called Random Access Memory (RAM).

The CPU can find any piece of data in RAM, when it needs it for processing.

RAM is volatile, meaning it holds data only when the power is on. When the power is off, RAM's contents are lost.

• The smallest usable unit of measure for memory is

the byte – the amount of memory required to hold

one character, like the letter A or the numeral 2.

• Computers work with larger chunks of data,

measured in multiple bytes, as shown below:

Unit Approx. Value Actual Value

(bytes) (bytes)

Kilobyte (KB) 1,000 1,024

Megabyte (MB) 1,000,000 1,048,576

Gigabyte (GB) 1,000,000,000 1,073,741,824

Terabyte (TB) 1,000,000,000,000 1,099,511,627,776

Looking Inside the Machine – How Memory is Measured

Input devices accept data and instructions from the

user or from another computer system. The keyboard

and mouse are examples of input devices.

Output devices return processed data back to the

user or to another computer system. The printer and

monitor are examples.

Communications devices (such as modems and

network interface cards) perform both input and

output, allowing computers to share information.

Storage devices hold data not currently being used by the CPU. Data is commonly stored on a magnetic or optical disk. Each type uses a special medium for storing data on its surface.

A disk drive is a device that reads data from and writes data to a disk. Most new computers feature a floppy disk drive, a hard disk drive, and an optical disk drive.

The most common optical storage devices are CD-ROM and DVD-ROM drives.

Software: Bringing the Machine to Life

• What is Software?

• System Software

• Application Software

Software is a set of electronic instructions that

tells the computer how to do certain tasks. A set

of instructions is often called a program.

When a computer is using a particular program, it

is said to be running or executing the program.

The two most common types of programs are

system software and application software.

System software exists primarily for the computer itself, to help the computer perform specific functions.

One major type of system software is the operating system (OS). All computers require an operating system.

The OS tells the computer how to interact with the user and its own devices.

Common operating systems include Windows, the

Macintosh OS, OS/2, and UNIX .

• Application software tells the computer how to

accomplish tasks the user requires, such as

creating a document or editing a graphic image.

• Some important kinds of application software are:

Word processing programs Spreadsheet software

Database management Presentation programs

Graphics programs Networking software

Web design tools and browsers Internet applications

Communications programs Utilities

Entertainment and education

Bringing the Machine to Life - Applications

What is a communications device?

Hardware component that

enables a computer to

send and receive data, instructions,

and information

Occurs over cables, telephone

lines, cellular radio networks,

satellites, and other

transmission media

What are the advantages of using computers?

What are the disadvantages of using computers?

Violation of

Privacy

Impact on

Environment

Impact on

Labor Force

Health Risks

The Brain of the computer

Silicon Chip (IC)

Pentium-4 has around 125 million transistors

Performs Billions of Instructions per second

Combines with other devices such as Memory and

I/O to form a “Microprocessor system”

The ―Calculator‖ Model

Should be able to ◦ Take Data

◦ Decode

◦ Execute

◦ Give Results

Control Unit; for decoding signals and activate

the devices (memories, buses, registers) in a

proper sequence

Arithmetic Unit; to perform mathematical

calculations

The series of steps taken by the CPU to execute

an instruction is called ‗Machine Cycle‘ ◦ Two smaller Cycles

Instruction Cycle

Execution Cycle

Instruction Cycle 1. Fetching: Fetching a command from memory

2. Decoding: Map the command to Instructions

Execution Cycle 1. Executing: CPU converts the instructions into

microcode and carries them out

2. Storing: (Optional) The CPU stores the result

somewhere in the memory

Memory; stores data and instructions Bus Interface Unit; transfers data in and out of

the Processor, instructions into the Processor Instruction Decoder; Decodes Instructions Arithmetic and Logic Unit; Performs Math,

Comparisons and Logical Operations on Integers Control Unit; Controls and Manages all the

Processing

Accessing RAM for Data/Instructions is slow

Solution: ◦ Registers attached to the ALU (for data currently in use)

◦ Cache Memory (for most frequently used data)

Internal Cache (on processor chip) Instruction Cache

Data Cache

External Cache (on motherboard)

Basic components of a microprocessor system combined on a single chip ◦ The CPU core

◦ RAM and ROM

◦ I/O ports (Parallel & Serial)

◦ Timers and Interrupts

◦ Analogue to Digital Converter (ADC), etc

Used in Autonomous Systems ◦ ovens, ATMs, vehicles

Advantage: ◦ Compact integrated design on single chip

◦ Reduced interface

Busicom‘s Desk Calculators 1971, Intel‘s 1st Microprocessor-4004 ◦ 2250 Transistors ◦ 740 KHz, 60,000 Op/sec ◦ 16 pins ◦ 10 Microns ◦ As Powerful as ENIAC

2001, Intel‘s P4 – Today‘s Processor ◦ 55 Million Transistors ◦ 32-bit Word size ◦ 2.2 GHz ◦ 2 ALUs ◦ 128 bit FPU ◦ 0.13 Micron

Presented by Gordon Moore, 1965, Intel Corp.

No. of Transistors on the Processor Chip Will Double in 18 months

One type is

a modem

What is a network?

◦ Collection of computers and devices connected together

Enables a

connection

between

computers

Cables

Cellular

radio

Telephone

lines

Satellites

Transmission

Media

Communications

Device

To share

What are the reasons to network?

Resources

Hardware

devices Software

programs

Data To save

time

and

money Information

What is a server?

A server manages

the resources on

a network Clients access

the resources

on the server

What is the Internet?

Worldwide collection of networks that connects

millions of businesses, government agencies,

educational institutions, and individuals

What is a graphical user interface (GUI)? Allows you to

interact with the

software using

graphics and icons

Controls how you

enter data and

how the screen

displays

information

What is system software?

Operating System (OS)

is a set of programs

that coordinates all

activities among

computer hardware

devices and allows

users to run

application software

Utility Programs allow the user to

perform maintenance-type tasks

usually related to managing a

computer, its devices or its programs

Programs that control or maintain the operations of

the computer and its devices

How do you install and run programs?

What is a programmer?

Someone who develops application or system software

Programmer writes instructions to direct computer to process data into information

Javascript program

Resulting Internet application

What are the categories of computers?

Personal Computers

(desktop)

Mobile Computers and

Mobile Devices

Midrange Servers

Mainframes

Supercomputers

Embedded Computers

What are the two most popular series of personal

computers?

PC and compatibles

use the Windows

operating system

Apple Macintosh

uses the Macintosh

operating system

(Mac OS)

What is a desktop computer?

Designed so all of the components fit entirely

on or under a desk or table

What is a notebook computer?

Portable, small enough

to fit on your lap

Also called a laptop

computer

Generally more

expensive than a

desktop computer

What is a Tablet PC?

Especially useful for taking

notes

Resembles a letter-sized

slate Allows you to write on the

screen using a digital pen

What are mobile devices?

Small enough to carry

in a pocket

Internet-enabled

telephone is a ―smart

phone‖

What is a handheld computer?

Used

by mobile

employees such as

meter readers and

delivery people

Small

enough to fit

in one

hand

What is a personal digital assistant (PDA)?

Provides personal organizer

functions

Calendar

Appointment book

Address book

Calculator

Notepad

What are smart phones and smart watches?

A smart watch is

an Internet-enabled

watch that automatically

adjusts to time zone changes

and stores personal

information

A smart phone is

an Internet-enabled

telephone that usually

provides PDA capabilities

What types of servers are there?

Midrange server: Powerful, large

computer that supports up to a few

thousand computers

Mainframe: Very powerful, expensive

computer that supports thousands of

computers

Supercomputer: The fastest, most

powerful, most expensive

computer. Used for applications

requiring complex mathematical

calculations

What is an embedded computer?

A special-purpose computer that functions as a

component in a larger product

What are some services found on the Internet?

How did the Internet originate?

Goal:

To function if

part of network

were disabled

Became

functional

September 1969

ARPANET

Networking project by

Pentagon’s Advanced

Research Projects

Agency (ARPA)

Goal:

To allow scientists

at different

locations to share

information

How has the Internet grown?

Today

More than 200 million host nodes

1984

More than 1,000 host nodes

1969

Four host nodes

Who controls the Internet?

World Wide Web

Consortium (W3C)

Oversees research, sets

standards and guidelines

Tim Berners-Lee, director

Internet2 (I2)

Internet-related research and

development project

Develops and tests advanced

Internet technologies

No one — it is a public, cooperative, and

independent network

Several organizations set standards

High-speed

connection

Slow-speed

technology

How can you connect to the Internet?

Dial-up access modem in your computer uses a

standard telephone line to connect to the Internet

Digital subscriber line (DSL),

cable telephone Internet

services (CATV), cable modem,

fixed wireless, and satellite modems

Connection is always on—

whenever the computer

is running

Connection must be established

each time you log on.

Slow but inexpensive

Choose the broadband connection that will best meet your Internet

connection needs

low quality

(click to start)

high quality

(click to start)

How might data travel the Internet using a cable modem connection?

What is a domain name?

Text version of Internet protocol (IP) address Number that uniquely identifies

each computer or device

connected to Internet

What is the World Wide Web (WWW)?

A worldwide collection of electronic documents

Each electronic document is called a Web page

Also called the Web

Can contain text, graphics, sound, video, and built-in connections

A Web site is a collection of related Web pages

What is a Web browser?

Microsoft

Internet

Explorer Netscape

Mozilla

Program that allows you to view Web pages

Opera Safari

How does a Web browser display a home page?

Step 2. If necessary,

connect to the

Internet

Step 3. Connection to the

Internet occurs, and a

home page displays

Step 1. Click the Web browser

program name

How do handheld computers and

cellular telephones access the Web?

Use a microbrowser

that displays Web

pages that contain

mostly text

Must be Web-enabled

What is downloading?

The process of a computer receiving information

Depending upon connection speed, downloading

can take from a few seconds to several minutes

What is a URL?

Unique address for a

Web page A web server delivers the

Web page to your computer

What is a link?

Item found elsewhere

on same Web page

Different Web page

at same Web site

Web page at a different

Web site

Built-in connection to another related

Web page location

What is a search

engine?

Program used to find

Web sites and Web

pages by entering

words or phrases

called search text Also called a keyword

What is multimedia? Application integrating text with other media

elements

Graphics

Animation

Audio

Video

Virtual reality

What graphics formats are used on the Web?

BMP

GIF

(pronounced JIFF)

JPEG

(pronounced JAY-peg)

TIFF

PNG

(pronounced ping)

What is a thumbnail? Small version of a larger

graphicc—used to

improve Web page display

time

Usually click

on thumbnail to

display larger

graphic

What is animation?

Appearance of motion created by displaying

a series of still images in sequence

What is audio?

Music, speech, or any other

sound

Individual compressed sound files

that you download from the Web

to your computer

Common Web audio file formats

are AA, AAC, AIFF, ASF, MP3, WAV,

WMA, RA, and QT

Once downloaded, you can play

(listen to) the contents of the

files

What is streaming audio?

The process of

transferring audio

in a continuous

and even flow

Enables you to

listen to music

as it downloads

to your computer

What is video?

Consists of full-motion images that are

played back at various speeds

MPEG (Moving Pictures Experts Group)

is popular video compression

standard

What is virtual reality (VR)? Use of computers to simulate real or imagined

environment

Appears as a three dimensional (3-D) space Used for games and many practical applications

What are plug-ins?

Programs that

extend the

capability of

a browser

You can

download many

plug-ins at no

cost from various

Web sites

What is Web publishing?

Step 1. Plan the

Web site

Step 2. Analyze and

design the

Web site

Step 3. Create the

Web site

Step 4. Deploy the

Web site

Step 5. Maintain

the Web site

Development and maintenance of Web pages

Business to business (B2B) Business providing goods and

services to other businesses

Consumer to consumer (C2C) One consumer sells directly to another

What is E-commerce?

Business to consumer (B2C) Sale of goods to general public

Short for electronic commerce

Business transaction that occurs over

the Internet

What is E-mail? Short for electronic mail The transmission of messages and files via a

computer network Messages can consist of simple text or can contain

attachments, such as documents, graphics, or audio/video clips

Internet access providers usually provide an e-mail program

Some Web sites—such as MSN Hotmail and Yahoo!—provide free e-mail services

One of the original services on the Internet

How do you send an e-mail message?

Step 1. Start an e-mail

program

(Microsoft

Outlook, for

example)

Step 2. Click the New Mail Message button

Step 3. Enter the recipient’s

e-mail address, the

subject, and the

message

Step 4. Click the Insert file button if

you want to attach a picture, for

example, and click Send

Step 5. The recipient opens the

message

What is an e-mail address?

Unique name that consists of a user name and

domain name that identifies the user

How does an e-mail message travel?

Step 1. Using e-mail

software, you

create and send

message

Step 2. Your software

contacts software

on your ISP’s

outgoing mail

server

Step 4. When recipient uses

e-mail software to check

for e-mail messages, the

message transfers from

incoming mail server to

recipient’s computer

Step 3. Software on outgoing mail server

determines best route for data and sends

message, which travels along Internet

routers to recipient’s incoming mail server

What is FTP?

File Transfer Protocol—Internet standard that

allows you to upload and download files with

other computers on the Internet

What is a mailing list? Group of e-mail

addresses given a single name

When a message is sent to the mailing list, everyone on the list receives the message

To add your name to a mailing list you must subscribe to it; to remove your name you must unsubscribe

What is a chat?

Real-time typed conversation

that takes place on a computer

Chat room is location on

server that permits users

to discuss topics of interest

What is instant messaging (IM)?

Step 2. The server determines if any of your

established friends, family, or

coworkers, called buddies, are online

Step 3. You send instant

messages to an

online buddy

Step 1. Login to the IM

server

IM Server

Step 4. Your Instant Message travels

through a messaging server and

then to the online buddy

messaging Server

A real-time Internet communications service that notifies you

when one or more people are online and allows you to exchange

messages or files

What is internet telephony?

Enables users to speak to other users over the

Internet using their computer

What is netiquette?

Golden Rule: Treat others as

you would like them to treat you.

Code of acceptable behaviors users should follow

while on the Internet

What is business software?

Software that assists people in becoming more

effective and efficient

What is word processing software?

Allows users to create and

manipulate text and graphics Clip art is a collection

of graphics that you can

insert in documents

What are popular word processing features?

AutoFormat AutoCorrect Collaboration

Columns Macros Ink Input Grammar

Checker

Mail Merge Research Reading

Layout

Smart Tags Thesaurus Templates Tables

Voice

Recognition

Tracking

Changes

Web Page

Development

What is a font?

A name assigned to a specific design of characters

Font size indicates the size of the characters in a

particular font in points (a single point is about

1/72 of an inch in height)

Font style adds

emphasis to a

font such as

bold, italic,

and underline

= SUM (C12:Y12)

= A1+B2 (*C12) = D1+E2 (*F12)

What is spreadsheet software?

Organizes data

Performs calculations and

recalculates when data changes

How is a spreadsheet

organized?

Columns identified by letters

Rows identified by numbers

A cell is the intersection of a

column and row

What is a function?

A predefined formula

that performs

common calculations =C4+C5+C6+C7+C8

=SUM(C4:C8)

What is charting?

Allows you to display spreadsheet data in graphical

form

What is database software?

Allows you to create

and manage data

Add, change, delete,

sort, and retrieve data

What are the parts of a

database?

A table contains records A record is a row in a

table that contains information about a given person, product, or event

A field is a column in a table that contains a specific piece of information within a record

How do you extract information from a database?

Can be sent as a report to the

printer Run queries to retrieve data

What is presentation graphics software?

Used to create visual aids for

presentations

A presentation is sometimes called

a slide show

What is note taking

software?

Enables users to enter

typed text,

handwritten

comments, drawings,

or sketches anywhere

on the page

Notes are organized

like a notebook

What is Personal Information Manager Software?

Includes a calendar,

address book,

synchronization

with

desktop computer

Most PDAs and many

smart phones

include PIM

functionality

What is a software suite?

A collection of individual

programs sold as

a single package

Two major advantages:

lower cost ease of use

What is project management software? Allows you to plan, schedule, track, and analyze

the events, resources, and costs of a project

What is accounting software?

Helps companies

record and report

their financial

transactions

Marketing Sales Distribution Customer

Service IT

What is enterprise computing software?

Large organizations require special

computing solutions

Each functional unit has specialized software

requirements

Human

Resources Accounting Engineering Manufacturing

What are some widely used stand-alone utility

programs?

Antivirus Program

Spyware Remover

Internet Filters

File Compression

File Conversion

CD/DVD Burning

PC Maintenance

What is a Web application?

A software application

that exists on a Web site,

such as maps and

directions Some Web applications

store your data and

information at their site

Some are free

What is an application service provider (ASP)?

Third-party organization

that manages and

distributes software

and services

on the Web

Allows companies

to outsource

information

technology (IT)

needs

How can I learn more about a software package?

Books

Web

School