Introduction To Computers

Computers: Tools for an Information Age

Chapter 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

Information Age  Evolving more rapidly than

Industrial Age  Will continue into the current century  Greater impact will be felt among network communities

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 Used Education  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

 Feed combinations

 Mixed breeding of plants

 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!

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

Hardware Basic Components of a Computer

Function of Computer System Data handling I P O S

Input Process Output 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 • Convert from electronic form to some other form • May display the processed results • Usable information Monitor or screen

Printer

 Text  Numbers

 Black and white  Color

 Symbols  Art  Photographs  Video

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

Connects Everyone! Individuals Businesses Organizations

Libraries Research labs Government

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