TTS2233 Information Technology Skills and Application

CHAPTER 1

INTRODUCTION

Objectives :

1. Define the term, computer2. Discuss the history & evolution of computer3. Describe the categories of computers4. Identify the components, types and functions of a computer5. Distinguish between system software and application software

1.1 What is Computer

Computer can be defined as an electronic device or machine working under a set of instruction, to accept data, process it into meaningful information and store it for future use.

1.2 History and Evolution of Computer

Babbage and The Countess, Difference and Analytical Engine

Most histories of the modern computer begin with the Analytical Engine envisioned by Charles Babbage.

Babbage's assistant and collaborator, Ada Lovelace, is said to have introduced the ideas of program loops and subroutines and is sometimes considered the first programmer.

1

TTS2233 Information Technology Skills and Application

Herman Hollerith, Tabulating Machine

In 1890 Herman Hollerith tabulating machine won in competition that was held to find some way to speed the counting process.

The machine uses electrical power rather than mechanical to drive the device.

In 1896 he himself founded the Tabulating Machine Company and in 1924 the successor to this company merged with two other companies to form International Business Machines Corporation – IBM.

The Modern Era

During late 1930s, Dr John V Atanasoff, a professor from Iowa State University spent time trying to build an electronic calculating device.

He and his assistant, Clifford Berry built the first digital computer that worked electronically; the ‘ABC’ for Atanasoff Berry Computer.

In 1924 the world first general purpose electronic digital computer was built by John Mauchly and his assistant J. Presper Eckert.

Their invention was the ENIAC – Electronic Numerical Integrator and Computer which able to multiply a pair of numbers in about three milliseconds.

2

TTS2233 Information Technology Skills and Application

Modern computers inherently follow the ideas of the stored program laid out by John von Neumann in 1945.

Essentially, the program is read by the computer one instruction at a time, an operation is performed, and the computer then reads in the next instruction, and so on.

Recently, computers and programs have been devised that allow multiple programs (and computers) to work on the same problem at the same time in parallel.

1.3 Categories of Computers

A. Personal computers

Desktop computers

Most often called personal computer (PC), also known as desktop and microcomputers

Designed so all of the components fit entirely on or under a desk or table

PC categories:i. Low-end computers

- Fine for home users, word processing, simple games, Internet accessii. Fully powered computers

3

TTS2233 Information Technology Skills and Application

- Good for heavy use of graphics, programming, or action-oriented gamesiii. Workstations

- Very high-end computers used by engineers, financial traders, and graphic designers

B. Mobile computers

Notebook (laptop)

Small, lightweight computers Portable, small enough to fit on your lap Usually more expensive than a desktop computer with equal capabilities

Tablet PC

Resembles a letter-sized slate Allows you to write on the screen using a digital pen Especially useful for taking notes

C. Mobile devices

4

TTS2233 Information Technology Skills and Application

• Small enough to carry in a pocket

• Examples: i. Smart phones - A smart phone is an Internet-enabled telephone that usually provides PDA capabilities

ii. Personal digital assistant (PDA) - Provides personal organizer functions (calendar, appointment book, address book, calculator, notepad) - Accepts input with hand-held stylus

iii Handheld computer - Small enough to fit in one hand - Used by mobile employees such as

meter readers and delivery people

iv. Portable media players - a consumer electronics device that is capable of storing and playing digital media.

v. Digital cameras - a camera that takes video or still photographs, or both, digitally by recording images via an electronic image

sensor.

D. Game consoles

• Mobile computing device designed for single-player or multiplayer video games

• E.g: Microsoft Xbox 360, Nintendo’s Wii, Sony’s Playstation 3

E. Server

Controls access to the hardware, software, and other resources on a network

5

TTS2233 Information Technology Skills and Application

Multi-user computers designed to serve the needs of medium-sizedorganizations

Hundreds or thousands of users connected Used for inventory, order-entry, and other company-wide Applications

F. Mainframe

A large, expensive, powerful computer that can handle hundreds or thousands of connected users simultaneously

Often used for applications with many users such as:

Reservations systems

Payroll processing

Insurance business

Large mail-order houses

E-mail servers

G. Supercomputers

The fastest, most powerful and most expensive computer

Used for very sophisticated applications requiring mammoth data manipulation:

Weather forecasting

6

TTS2233 Information Technology Skills and Application

Space exploration

Oil exploration

Weapons research

Special effects for movies

H. Embedded computers

A special-purpose computer or a control system that functions as a component in a larger product

designed to perform a specific task

Example of products that contain embedded computers: i. Automobiles (antilock brakes, airbag controllers, cruise control, etc)

ii. Process controllers and robotics (remote monitoring systems, medical devices, machine controllers, etc)

iii. Computer devices and office machine (keyboard, printers, copy machine, etc)

iv. Home automation devices (appliances – washing machine, microwave ovens, sprinkling system, security monitoring systems, etc)

v. Consumer electronics (mobile and digital telephones, digital cameras, DVD player and recorders, etc)

1.4 Core Component, Types and Computer Functions

7

TTS2233 Information Technology Skills and Application

Components

i. Input devices – Allows you to enter data and instructions into a computer

ii. Output devices – Hardware component that conveys information to one or

more people

iii. System unit – Case that contains the electronic components of the computer

that are used to process data

iv. Storage devices – Holds data, instructions, and information for future use

v. Communication devices – Enables a computer to send and receive data,

instructions, and information to and from one or more computers or mobile

devices

Types

i. Analog – Uses arithmetic and logical operations. Eg: computer used in flight centres to measure pressure and temperature

ii. Digital – Operations are on electrical input. Eg; ON=1 OFF=0 used in your personal computers

iii. Hybrid – Combine both operations in analog and digital computers Eg; computer used in hospital to measure patient’s heartbeat

Computer functions (Information Processing Cycle)

8

TTS2233 Information Technology Skills and Application

All computers must be able to:

• Gather data

• Process data

• Store data

• Disseminate data

• Display data

1.5 Concept of Hardware and Software

Hardware

- the mechanical, magnetic, electronic, and electrical components making up a computer system

- Terminologies:

i. Input devices – e.g: mouse, keyboard, scanner, microphone, etc

ii. Output devices – e.g: screen, speaker, printer, etc

iii. System unit – consist of processor, memory, expansion cards, etc.

iv. Storage devices – e.g: diskette drive, hard disk, CD-ROM or DVD-ROM drive, USB flash drive, memory card

9

TTS2233 Information Technology Skills and Application

v. Communication devices – modem, router, hub, NIC, etc

Software

- also called a program, consists of a series of related instructions, organized for a common purpose, that tells the computer what tasks to perform and how to perform them

- 2 types :

i. Systems software

- Programs that control or maintain the operations of the computer and its devices

- Operating System (OS) a set of programs that coordinates all activities among computer hardware devices

- Utility Programs allow the user to perform maintenance-type tasks usually related to managing a computer, its devices or its programs

ii. Application software

- Programs designed to make users more productive

- Types: Word Processing, Spreadsheet, Database, Presentation Graphics

10