HISTORY OF COMPUTERS

Introduction to the World of Computers

Computers in Your Life Computers are prevalent in the home, in the school, in the

workplace, and on the go.

Most professional jobs and skilled trades heavily depend on the creation, collection, evaluation and dissemination of information.

Uses of computers include word processing, e-mail exchange, shopping, research, investments management, playing games and many other applications.

Knowledge of computers assists the consumer to purchase the right computer, save money on repairs and use the computer to maximum benefit.

What Is a Computer and What Does It Do?

A computer is a programmable electronic device that accepts data and performs operations on that data.

Input—entering data into the computer.

Processing—performing operations on the data.

Output—presenting the results.

Storage—saving data, programs, or output for future use.

Computers Then and Now

The computer as we know it is a fairly recent invention.

The history of computers is often referred to as generations, from pre-computers and early computers (before 1945) to fifth generation computers (now and the future).

Each new generation is characterized by a major technological development.

Hardware

The physical parts of a computer are collectively known as hardware.

Internal hardware is located within the main box (system unit) of the computer.

External hardware is located outside the system unit and plug into connectors called ports located on the exterior of the system unit.

Hardware, Cont’d. An input device is used to input data into the computer.

A processing device performs calculations and comparisons necessary for processing. The main processing device is the central processing unit (CPU).

An output device presents the results to the user.

Storage devices are used to save data, programs or output.

Communication devices allow the user to communicate with others and access remote information.

Software

The programs or instructions used to tell the computer hardware what to do.

System software allows a computer to operate and run application software.

Application software performs specific tasks or applications.

Data and Information

Data = raw, unorganized facts. Can be in the form of text, graphics, audio, or

video.

Information = data that has been processed into a useful form.

Computer Users and Professionals

Computer users, or end users, are the people who use a computer to obtain information.

Programmers are computer professionals whose job it is to write the programs that computers use.

Computer Networks and the Internet A computer network links computers together so

that users can share hardware, software, and data, as well as electronically communicate with each other.

Network servers manage resources on a network.

Clients are computers on the network that access resources via the network server.

Computer networks are commonly found in businesses, schools, and homes.

The Internet

The Internet is the largest and most well-known computer network in the world.

Individuals connect to the Internet using an Internet service provider (ISP).

E-mail and accessing Web pages are two of the most common Internet activities.

Accessing a Network

Need a modem or network adapter to connect to the network.

Software (often built into the operating system) allows you to log on to the network and access resources.

Need an ISP and Web browser to access Internet resources.

Many networks and Internet connections require a user ID and password to log on to the network.

Computers to Fit Every Need Five basic categories

Mobile devices

Personal computers

Midrange servers

Mainframe computers

Supercomputers

Mobile Devices Very small computing devices.

Usually based on a wireless phone or pager.

Many can be used to access e-mail and Web pages.

Personal Computers

Microprocessors allow for the creation of computers small enough to fit on a desk or lap.

PC compatible—based on the original IBM PC; typically run the Windows operating system.

Macintosh—a type of personal computer manufactured by Apple.

Personal Computers, Cont’d.

Desktop computers—small enough to fit on or next to a desk. Can use:

Desktop case

Tower case

All-in-one case

Personal Computers, Cont’d.

Portable PCs—designed to be carried around.

Notebook computers

Tablet PCs (either slate or convertible)

Handheld computers (pocket computers)

Personal Computers, Cont’d.

PCs designed for just network use are referred to as network computers (NCs) or thin clients.

Devices designed just for Internet access are called Internet appliances.

Midrange Servers Medium-sized computers, also called minicomputers

or midrange computers.

Fall between microcomputers and mainframes in processing power.

Mainframe Computers

Standard choice for most large organizations.

Specialize in high-volume processing of business transactions.

Also called high-endservers or enterprise-class servers.

Supercomputers

Used for applications that have extraordinary demands for processing power.

Offer very fast speeds and extreme degrees of accuracy.

Commonly created today by connecting hundreds of smaller computers to form a supercomputing cluster.

Computers and Society

The information age = the prominence of information technology.

There are many benefits of a computer-oriented society, including making many tasks in our lives go much faster.

Risks include health, security, ethical, and privacy concerns.

Summary Slide

Computers in your life What is a computer and what does it do?

Computers networks and the Internet

Computers to fit every need

Computers and society