CHAPTER 1 INTRODUCTION

Objectives : Define the term, computer Discuss the history & evolution of computer Describe the categories of computers Identify the components, types and functions of a computer Distinguish between system software and application software

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.

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.

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.

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.

Categories of Computers Embedded computers Supercomputers Mainframes Servers Game consoles Mobile computers and mobile devices Personal computers

Personal Computers A personal computer can perform all of its input, processing, output, and storage activities by itself Two popular architectures are the PC and the Apple Desktop computer

Mobile Computers and Mobile Devices Personal computer you can carry from place to place Examples include notebook computers, laptop computers, netbooks, ultra-thins, and Tablet PCs Mobile Computer Computing device small enough to hold in your hand Examples include smart phones, PDAs, handheld computers, portable media players, and digital cameras Mobile Device

Mobile Computers and Mobile Devices Notebook computer Tablet PC Smart phone PDA

Mobile Computers and Mobile Devices Handheld computer Portable media player Digital camera

Game Consoles A game console is a mobile computing device designed for single-player or multiplayer video games

Servers A server controls access to the hardware, software, and other resources on a network Provides a centralized storage area for programs, data, and information

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

Supercomputers A supercomputer is the fastest, most powerful computer Fastest supercomputers are capable of processing more than one quadrillion instructions in a single second

Embedded Computers An embedded computer is a special-purpose computer that functions as a component in a larger product Consumer Electronics Mobile and digital telephones Digital televisions Cameras Video recorders DVD players and recorders Answering machines Home Automation Devices Thermostats Sprinkling systems Security monitoring systems Appliances Lights Automobiles Antilock brakes Engine control modules Airbag controller Cruise control Process Controllers and Robotics Remote monitoring systems Power monitors Machine controllers Medical devices Computer Devices and Office Machines Keyboards Printers Faxes Copiers

Embedded Computers

Core Component, Types and Computer Functions Components

Input devices – Allows you to enter data and instructions into a computer Output devices – Hardware component that conveys information to one or more people System unit – Case that contains the electronic components of the computer that are used to process data Storage devices – Holds data, instructions, and information for future use Communication devices – Enables a computer to send and receive data, instructions, and information to and from one or more computers or mobile devices

Types of Computer: Analog – Uses arithmetic and logical operations. Eg: computer used in flight centres to measure pressure and temperature Digital – Operations are on electrical input. Eg; ON=1 OFF=0 used in your personal computers Hybrid – Combine both operations in analog and digital computers Eg; computer used in hospital to measure patient’s heartbeat

Computer functions (Information Processing Cycle)

All computers must be able to: • Gather data • Process data • Store data • Disseminate data • Display data

Concept of Hardware and Software - the mechanical, magnetic, electronic, and electrical components making up a computer system.

Terminologies: Input devices – e.g: mouse, keyboard, scanner, microphone, etc   Output devices – e.g: screen, speaker, printer, etc System unit – consist of processor, memory, expansion cards, etc. Storage devices – e.g: diskette drive, hard disk, CD-ROM or DVD-ROM drive, USB flash drive, memory card Communication devices – modem, router, hub, NIC, etc

SOFTWARE 2 types : i- System Software ii- Application software

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

APPLICATION SOFTWARE Programs designed to make users more productive Types: Word Processing, Spreadsheet, Database, Presentation Graphics