Introduction to Computers

Computers: Tools for an Information Age

Chapter 1Chapter 1

Objectives

Describe the three fundamental characteristics of computers

Describe at least four areas of society in which computers are used

Identify the basic components of a computer system: input, processing, output, and storage

List some common input, output, and storage media

Distinguish data from information Describe the significance of networking Explain the significance of the Internet Explain the various classifications of computers

Contents

Information Age Computer Literacy Where Computers Are Used Computer System Network Classifications of Computers

Evolving more rapidly than Industrial Age

Will continue into the current century

Greater impact will be felt among network communities

Information Age

Forging a Computer-Based Society:

From physical to mental

From muscle-power to brain-power

What is a computer? 

A computer is a special type of electronic calculating device with internal storage (RAM- hardware) capabilities that performs mathematical and logical operations (ALU) on the data through its Central Processing Unit-CPU, (hardware) based on the set of program instructions or language (software) and produces result in the form of meaningful and useful output.

Computer

A machine that can be programmed to accept data (input), process it into useful information (output), and store it away (in secondary storage device) for safekeeping or later reuse

Process is directed by the software but is performed by the hardware.

CAPABILITIES OF COMPUTER

1. High-speed processing - the computer can process data faster than any other machine with its speed of 1/1M of a sec

2. Repetitiveness - a computer can perform the same operation millions of times in exactly the same way.

3. Accuracy - a computer's high-speed processing gives 99.99% error free results.

4. Arithmetic and Logical Operations - the computer can make decisions based on alternative course of action.

5. Store and Retrieve Information - computers can store information in the memory and use them when needed.

Limitations of Computer

1. A computer cannot generate information on its own. It must be told what to do, when to start, stop, compute, and make the next move via a program 2. A computer can detect errors but generally cannot correct them on its own. 3. Computers cannot combine ideas or take the best parts or several ideas to come up with a brand new idea of its own.4. Computers need periodic maintenance support.5. A Computer is subject to occasional breakdown and wear out .

A Computer Now…

Where is it used? Bank withdrawal Supermarket and department stores Drive the car E-Commerce

Do you need a Personal Computer? Many Filipinos have one at home Many more use at work

Will I use a computer in my future career? Almost every job will involve use of a computer

Computer Literacy

Awareness Importance Versatility Pervasiveness in our society

Knowledge What are computers How do computers work Terminology

Interaction Use some simple computer applications

Where Computers Are UsedEducation Teaching and testing

aid

Learning by doing

Computer-based instruction

E-Learning and Distance Learning

Computers in Retailing

Bar codes for pricing and inventory

Recording and monitoring in Shipping

Computers in Energy

Locate oil, coal, natural gas, and uranium

Monitor the power network

Meter reading or ground works monitoring

Computers for Law Enforcement

National fingerprint files

National files on criminal

Computer modeling of DNA – Deoxyribonucleic Acid

Computers in Transportation

Cars- automatic

Run rapid transit systems- LRT, MRT

Load containerships

Track railroad cars

Monitor airline traffic

Computers in Finance

Record keeping to monitor expense

Banking by phone or on-line request

Credit cards

Computers in Agriculture

Crop growth information

Mixed breeding of plants

Feed combinations

Livestock breeding and performance

Computers in Government

Forecast weather

Manage parks

Process immigrants

Social Security benefits

Taxes

Municipal and City Government Services

Computers at Home Educational tool Record keeping Letter writing Budgeting Drawing and editing pictures Newsletters Connecting with others Digital Entertainment

Computers in Health and Medicine

Monitor patients

Electronic imaging

Diagnose illnesses Assist the disabled

Computers for Robotics

Perform jobs that are dangerous for humans

Factory work

Mimic how human works

Where Computers Are Used

The Sciences Research Simulation Connectivity

Communication Telecommuting

Where Computers Are Used

Training Airline pilots Railroad engineers

Paperwork• Term paper

• Record keeping

Computers are all around!

Grocery store School Library Bank Mail

We interact with computers everyday!

We interact with computers everyday!

Computer System Components

People

Software

Hardware

Dataware

People

Computer programmer – person who writes programs

Users or End-users – make use of the computer’s capabilities

Software

Programs- such as Windows Operating System, MS-Office

Set of instructions that directs the hardware to do a required task and produce the desired results

HardwareBasic Components of a Computer

Function of Computer System

Data handlingI Input

P Process

O Output

S Storage

Input devices

Accept data or commands and convert them to electronic form

Getting data into the computer Typing on a keyboard Pointing with a mouse Scanning with a wand reader or bar-code reader Terminal

Output devices

Monitor or screen Text Numbers Symbols Art Photographs Video

Printer Black and white Color

• Convert from electronic form to some other form

• May display the processed results

• Usable information

The Processor

Central Processing Unit (CPU)

Converts data to useful information

Interpret and execute instructions

Communicate with input, output and storage

Two Types of Storage

Secondary storage

long-term storage

Primary storage or memory

temporary storage

Memory / Primary Storage

RAM - Temporary storage

Holds input to be processed

Holds results of processing

Contains the programs to control the computer and manipulate input into output

Volatile

Secondary Storage

Long-term storage Non-volatile For safekeeping and later re-use

Secondary Storage Examples

Magnetic disks – read and written by magnetic disk drive Hard disk Diskette

Optical disks – read and written by optical disk drives CD-ROM DVD-ROM

Magnetic tape – read and written by magnetic tape drives Primarily used for back-up

Computer System

Computer CPU Memory

Peripheral equipment Connected to the computer by a cable Input, output, storage

Network

Definition A system that uses communications equipment to

connect computers and their resources.

Types Local area network (LAN) – connects computers in

close proximity, within a building or a particular location

Metropolitan area network (MAN) – connect computers between buildings in the same geographic area

Wide area network (WAN) – connects computers over great distances

Internet

Collection of networks No ownership No central source for services available No comprehensive index of what information is

available

Individuals

Businesses

Organizations

Libraries

Research labs

Government

Connects Everyone!

Getting Connected

User’s computer must connect to a server

Server must communicate using TCP/IP

The user can purchase access to a server from an ISP (Internet Service Provider)

Internet – What Can You Do?

WWW – World Wide Web

FTP – File Transfer Protocol

E-mail

UseNet

IRC – Internet Relay Chat

Bulletin Boards

World Wide Web

• Browser – program that allows the user to move around and explore the Internet

• Use the mouse to point and click on text and graphics

• Web page

• Web site

• Home page

Classifications of Computers

According to purpose According to data handled According to size

According to purpose

General purpose- a machine that can be used to process many types of applications. Ex microcomputers

Special purpose- a machine that can be used for a specific application or just ONE application. Ex: Weather Forecasting and Airlines Reservation

According to data handled

Analog computers- a computer that manipulates continuous or approximate types of data

Digital computers - a computer that manipulates discrete types of data

Hybrid computers- a computer that can manipulate both analog or digital types of data

According to size or capacity

Microcomputer – smallest in size and the cheapest. It can handle thousands of records.

Minicomputer – the medium size computer, bigger and more expensive than the microcomputer

Mainframe – a large computer that can handle millions of data, Support multiple user, does server tasks

Supercomputer – is a very large computer that manipulates billions of data

Classifications of Computers

Use the computer that fits your needs Based upon

Size Speed Cost Portability Number of simultaneous users supported Available software Typical use

Personal Computers

Other names PC Microcomputer Home computer

Categories Low-end functional Fully powered Workstations Net computer or net box (Web TV)

Desktop Models

Notebook Computers

Portable Lightweight Fits in a briefcase Battery operated

Laptop Larger Heavier

More expensive that desktop models

Handheld Computers

Personal Digital Assistant (PDA) Scheduling Addresses Handwritten input May offer wireless e-mail and fax

Pocket More power than PDA Runs basic productivity software