Introductory Computer Science - Chapter One: Introduction and History of Computers PDF

Introductory Computer Science explores the fundamentals of computing, focusing on the history and evolution of computers. This chapter provides a comprehensive overview of what constitutes a computer, detailing its functions, data processing, and the significance of programming. Key concepts include the definitions of data, programs, and information, along with examples of procedures and functions in programming. Ideal for students beginning their journey in computer science, this chapter lays the groundwork for understanding more complex topics in subsequent chapters.

Key Points

Explains the definition and functions of computers in everyday use
Covers the history and evolution of computer technology
Discusses the importance of data, programs, and information in computing
Introduces programming concepts, including procedures and functions

Joseph Akujieze

118 pages

Language:English

Type:Textbook

Computer Science

Joseph Akujieze

118 pages

Language:English

Type:Textbook

Computer Science

314

INTRODUCTORY COMPUTER SCIENCE

CHAPTER ONE: INTRODUCTION AND HISTORY OF COMPUTERS.

1.0 INTRODUCTION

Computers are indeed some of the most interesting and complex items of technology in everyday

use, but they are only around in such numbers because they are useful tools. A computer is a

device which accepts data in one form and processes it to produce data in another form . This

definition can be put in a more explicit form as, computer is an electronic device that can receive

a set of instructions, or program, and then carry out this program by performing calculations on

numerical data or by compiling and correlating other forms of information. Note the three words

used in the definition of computer, data, program, and information. “Data” is the name given to

basic facts, e.g. the number of items sold by a business, the name of a customer, or the numerical

values used in mathematical formulae. A program is a set of instructions which is written in the

language of the computer. It is used to make the computer perform specific task such as

calculating interest to be paid to savings account holders or producing a payroll. Information

refers to a result when data is converted into a more useful or intelligible form. In this situation

data is said to be processed into information.

From the foregoing definition of a computer, it has a simplified representation as in Fig.1.1.

INPUT PROCESS OUTPUT

e.g. 5,4 Add 5 and 4 9

Fig. 1.1. An INPUT- PROCESS- OUTPUT diagram

A computer can be formally defined as a device which works under the control of a stored

program, automatically accepting and processing data to produce information which is the result

of that processing. In this line, computer science is concerned with the application of scientific

principles to the design, construction and maintenance of systems based upon the use of

computers. It therefore includes a study of what computers are, how they work and how they are

used.

1.2 THE EVOLUTION OF COMPUTER SYSTEMS

Most modern Computers are based upon general design principles which were established during

the 1940s and which have not changed greatly since then. In striking contrast, changes in

technology have revolutionized the ways in which Computers are made. The origins of

Computers can be stressed to the ancient times when different methods were used to represent and

store data. For example, the herdsmen used pebbles, sticks, or scratches on stones to count and

represent the number of animals in their care. The use of pebbles was latter on replaced with

stylized pictures or symbols to represent objects, numbers and ultimately languages. Such

representations provided a means of storing information for subsequent retrieval and use.

1.2.1 The Development of Calculating Devices

For over two thousand years ago, some simple calculating devices, notable among them abacus

were already in used. Abacus is still used today in parts of Asia. This device is a mechanized

pebble counter in which beads are strung on wires or strings held in a frame. The beads are slid

along the wires when counting, adding, etc. Subsequent significant developments of calculating

devices took place especially in the seventeenth century. Prominent among them include the

invention of logarithms by John Napier, a Scottish mathematician in 1614. Logarithms aid

manual multiplication and division. Later in 1617, Napier’s bones were devised for use as

multiplication aids. Napier’s bones were a set of rods carved from bone. Three years later, that

was in 1620 to be precise, William Oughted, an English Parson, invented an analog calculating

device otherwise called the slide rule. The rule has scales divided in fixed and sliding scales

respectively. Francis Bacon in 1623 made the first known use of binary codes for number

representation.

The first true calculating (adding) machine, a precursor of the digital computer, was devised in

1642 by the French philosopher and mathematician Blaise Pascal.. This device employed a series

of ten-toothed wheels, each tooth representing a digit from 0 to 9. The wheels were connected so

that numbers could be added to each other by advancing the wheels by a correct number of teeth.

It consisted of a series of six numbered dials and a ratchet ‘carry” mechanism. Multiplication and

division using this device were quite slow and laborious. On the other hand addition and

subtraction were straight forward. In the 1960s Pascal’s contribution to computing was

recognized when a renowned mathematician professor Niklaus Wirth of Zurich named his new

programming language “ Pascal” after Blaise Pascal. The laborious processes in multiplication

and division experienced using Pascal’s device was simplified when a German mathematician,

Gottfried Von Leibniz invented a calculating machine capable of true multiplication and

division in 1671. The machine was a development of Pascal’s idea. The new feature was a shift

mechanism. Pascal had already devised a method of number complements for use in subtraction.

Early in the nineteenth century, a French textile manufacturer made a brilliant imaginative efforts.

Between 1802 and 1804 the French inventor Joseph Marie Jacquard perfected a mechanical

means of automatically controlling weaving looms to facilitate the production of woven cloth

with complex patterns. The machine, called “ the Jacquard loom”, was programmed by means of

special punched cards which stored information about the required patterns in the cloth. These

punched cards were strung tightly together side by side in a long continuous strip. They were

automatically fed through a loom mechanism in sequence with the purpose of controlling the

loom’s weaving action. It is generally accepted that Jacquard’s loom was the start of a chain of

developments which led to the robot operated factory production lines of today. Jacquard’s work

had led also to the automation of calculations. Within a few years of Jacquard’s invention, a

professor of mathematics at Cambridge University, Charles Babbage in 1822 demonstrated a

small working model of his “Difference Engine” to the Royal Society. Babbage’s demonstration

won him government backing who wished to produce a larger machine able to generate reliable

astronomical and mathematical tables containing values accurate to 20 decimal places. The

machine was never completed because of mechanical difficulties. In 1884 Babbage designed and

developed the concept of an “Analytic Engine”. It was essentially a general purpose automatic

calculator. Its design owed much to Jacquard’s invention and incorporated many features present

in modern computers inter alia

1) Data and program instructions fed in via a device using a suitable medium (punched cards)

2) Storage facilities for data and instructions

3) A mechanized unit for calculation- a ”mill”

4) A suitable output device.

Overview

Introductory Computer Science - Chapter One: Introduction and History of Computers

/ 118

314

Figures

Introductory Computer Science - Chapter One: Introduction and History of Computers — CHAPTER TWO:

Mouse is a small device held in hand and pushed along a flat surface. It can move the cursor in

Magnetic Ink Character Recognition (MICR)

Optical Mark Reading and Recognition (OMR)

Objective type answer papers in examinations in which large number of candidates

Introductory Computer Science - Chapter One: Introduction and History of Computers — The advantage of this method is that information is entered at its source and no further

It is used to store the Programs and data. One of the important element of a computer is the main

The printer presents information on paper. Such information on paper is called hard copy. All

Introductory Computer Science - Chapter One: Introduction and History of Computers — Figure 5.11

Introductory Computer Science - Chapter One: Introduction and History of Computers — Figure 5.15

FAQs

What are the main components of a computer according to Chapter One?

Chapter One defines a computer as a device that processes data to produce information. The main components include input, processing, and output units. Input refers to the data entered into the computer, processing involves the manipulation of that data according to a set of instructions or programs, and output is the final information produced, which can be displayed or printed.

How did early calculating devices evolve into modern computers?

The evolution of calculating devices began with simple tools like the abacus and progressed through significant inventions such as Blaise Pascal's adding machine and Charles Babbage's Analytical Engine. Babbage's design included essential features of modern computers, such as input methods, storage, and processing units. This historical context illustrates the gradual transition from mechanical devices to electronic computers, highlighting the foundational principles established in the 1940s.

What role did Lady Ada Lovelace play in the history of computing?

Lady Ada Lovelace is recognized as one of the first programmers due to her work on Charles Babbage's Analytical Engine. She created algorithms intended for the machine, demonstrating early insights into programming. Her contributions are significant as they laid the groundwork for future developments in computer science, and the programming language 'Ada' is named in her honor.

What was the impact of the invention of the transistor on computers?

The invention of the transistor in 1948 marked a pivotal change in computer technology, leading to the development of smaller, faster, and more reliable computers. Transistors replaced vacuum tubes, resulting in reduced power consumption and increased longevity of computing devices. This advancement facilitated the transition from first-generation to second-generation computers, enhancing the overall efficiency and performance of computing systems.

What is the significance of Boolean Algebra in computer science?

Boolean Algebra, developed by George Boole, is crucial in computer science as it provides a framework for representing and manipulating logical expressions. This algebraic system underpins the design of digital circuits and programming languages, enabling computers to perform logical operations. Its theoretical foundations have influenced various aspects of computing, including circuit design and algorithm development.

How did Herman Hollerith contribute to the evolution of computers?

Herman Hollerith's invention of a mechanical tabulator using punched cards revolutionized data processing, particularly for the 1890 U.S. Census. His system significantly reduced the time required to process census data, demonstrating the potential for automation in data handling. This innovation laid the groundwork for future developments in computing technology, leading to the establishment of the company that became IBM.

What defines the first generation of computers?

The first generation of computers, spanning from 1945 to 1956, was characterized by the use of vacuum tubes for circuitry and magnetic drums for memory. These computers were large, expensive, and primarily used for specific tasks, with programming done in machine language. Notable examples include the ENIAC and UNIVAC, which laid the foundation for subsequent generations of computing technology.