1

How is a computer defined?

What Is a Computer?

Electronic device operating under the control of instructions stored in its own memory

The computer first, Accepts data such as raw facts, figures, and symbol then, Processes data into information (Data that is organized, meaningful, and useful ) finally, Produces and stores results

A computer system includes a computer, peripheral devices, and software (Group of Computer Parts)

•Before the 1500s, in Europe, calculations were made with an abacus

Invented around 500BC, available in many cultures (China, Mesopotamia, Japan, Greece, Rome, etc.)

•In 1642, Blaise Pascal (French mathematician, physicist, philosopher) invented a mechanical calculator called the Pascaline

•In 1671, Gottfried von Leibniz (German mathematician, philosopher) extended the Pascaline to do multiplications, divisions, square roots: the Stepped Reckoner

None of these machines had memory, and they required human intervention at each step

History

• In 1822 Charles Babbage (English mathematician, philosopher), sometimes called the “father of computing” built the Difference Engine

• Machine designed to automate the computation (tabulation) of polynomial functions (which are known to be good approximations of many useful functions)

– Based on the “method of finite difference”

– Implements some storage

• In 1833 Babbage designed the Analytical Engine, but he died before he could build it

– It was built after his death, powered by steam

Introduction To Computers First

Generation Second Gen.

Third Gen.

Fourth Gen.

Technology Vacuum Tubes

Transistors Integrated Circuits (multiple transistors)

Microchips (millions of transistors)

Size Filled Whole Buildings

Filled half a room

Smaller Tiny - Palm Pilot is as powerful as old building sized computer

The use of binaryIn the 30s Claude Shannon (the father of “information theory”) had proposed that the use of binary arithmetic and boolean logic should be used with electronic circuits

The Von-Neumann architecture

CPU Memory

I/OSystem

Man Computer

0 0

1 1

2 10

3 11

4 100

5 101

6 110

7 111

8 1000

9 1001

Basic Terminology Computer

A device that accepts input, processes data, stores data, and produces output, all according to a series of stored instructions.

Hardware Includes the electronic and

mechanical devices that process the data; refers to the computer as well as peripheral devices.

Software A computer program that

tells the computer how to perform particular tasks.

Network Two or more computers and

other devices that are connected, for the purpose of sharing data and programs.

Peripheral devices Used to expand the

computer’s input, output and storage capabilities.

Computer Performance and Processing

Boot Process Bootstrapping is the process of starting up a computer from

a halted or powered-down condition. Data

Refers to the symbols that represent facts, objects, or ideas. Information

Processed, stored, or transmitted data. Output

Consists of the processing results produced by a computer. Input

Information that is created or collected and fed into the system.

Base 2 binary code A numbering system with only two digits numbers are 0 and

1. All numbers are comprised of only these two digits.

Introduction To Computers

Introduction To Computers

• Characteristics of Computers• High Processing Speed

• Accuracy (Computer Never Makes Mistake)

• Reliability

• Versatility (Perform any task)

• Diligence (Never Tired)

Types of Computer (Micro)

A personal computer; designed to meet the computer needs of an individual.

Provides access to a wide variety of computing applications, such as word processing, photo editing, e-mail, and internet.

Desktop Microcomputer

A microcomputer that fits on a desk and runs on power from an electrical wall outlet.

The CPU can be housed in either a vertical or a horizontal case.

Has separate components (keyboard, mouse, etc.) that are each plugged into the computer.

Laptop Computer

A portable, compact computer that can run on an electrical wall outlet or a battery unit.

All components (keyboard, mouse, etc.) are in one compact unit.

Usually more expensive than a comparable desktop.

Sometimes called a Notebook.

Workstation

Powerful desktop computer designed for specialized tasks.

Can tackle tasks that require a lot of processing speed.

Can also be an ordinary personal computer attached to a LAN (local area network).

Supercomputer

A computer that was the fastest in the world at the time it was constructed.

Can tackle tasks that would not be practical for other computers. Typical uses

Breaking codes Modeling weather systems

Mainframe

Large expensive computer capable of simultaneously processing data for hundreds or thousands of users.

Used to store, manage, and process large amounts of data that need to be reliable, secure, and centralized.

Usually housed in a closet sized cabinet.

Server

Purpose is to “serve.” A computer that has the

purpose of supplying its users with data; usually through the use of a LAN (local area network).

Handheld

Also called a PDA (Personal Digital Assistant).

A computer that fits into a pocket, runs on batteries, and is used while holding the unit in your hand.

Typically used as an appointment book, address book, calculator, and notepad.

Can be synchronized with a personal microcomputer as a backup.

Computer Components Hardware

19

The Components of a Computer

What is an input device? Hardware used

to enter dataand instructions

_____

20

The Components of a Computer

What is an output device? Hardware that

conveys information to a user

______

21

The Components of a Computer

What is the system unit? Box-like case

containingelectroniccomponentsused to processdata

22

What is the magical inside the black box?

CPU

Memory card

Sound Card

Video Card

Storage Units

Power

Supply

23

The Components of a Computer

What are two main components on the motherboard?

Central Processing Unit (CPU)Also called a processorCarries out instructions that tell computer what to do

MemoryTemporary holding place for data and instructions

24

The Components of a Computer

What is a hard disk?

Provides much greater storage capacity than a floppy disk or Zip® disk

Housed inside the system unit

25

The Components of a Computer

What is a compact disc? Flat, round, portable metal disc

CD-ROM CD-RW

Capacity: 673~768 MB

DVD-ROM DVD+RW

Capacity:4.7 ~ 17.1 GB

26

Software

Software contains the instructions that the hardware executes to perform an information processing task

Without the aid of software, the computer hardware is useless

Two categories of software Application System

27

Two main types of software

Application software - software used to solve specific problems or perform specific tasks

System software - handles tasks specific to technology management and coordinates the interaction of all technology devices Operating system software - supports the

application software and manages how the hardware devices work together

Utility software - provides additional functionality to the operating system

28

Application Software

Application software is used for specific information processing needs, including: Payroll Customer relationship management Project management Training Word processing and many others

29

Application Software (continued)

Personal productivity software :used to perform personal tasks such as writing a memo, creating a graph, or creating a slide presentation

Examples: Microsoft Word Microsoft Excel Internet Explorer Quicken