BASiC CHAPTER-1 FUNDAMENTALS OF COMPUTER OBJECTIVES OF THIS LESSON

 

CHAPTER-1

FUNDAMENTALS OF COMPUTER

OBJECTIVES OF THIS LESSON

• This lesson is aimed to make you understand the following   about   a computer system:
•     Historical evolution of computers and computer generations
•   Working model of a digital computer and functions of a digital computer
•     Basic characteristics of digital computer
•     Types of computer
•   Classification of digital computer-
•   Similarities between human beings and computer system

STRUCTURE OF THIS LESSON

1.1.    Introduction

1.2.    Historical Evolution of Computer

1.3.    Computer Generations

1.3.1. First Generation (1946-1959)

1.3.2. Second Generation (1959-1965)

1.3.3. Third Generation (1965-1971)

1. 3.4.  Fourth Generation (1971-1985)

1.3.5. Fifth Generation (Beyond 1985 and Till- Date )

1.4.    Model of a Digital Computer

1.5.    Functioning of a Digital Computer

1.6.    Characteristics of Digital Computer

1.7.    Classification of Digital Computer

1.7.1.  Analog Computer

1.5.2. Digital Computer

1.7.3. Hybrid Computer

1.7.4. Difference between Analog and Digital Computer

1.8.    Classification of Digital Computer

1.8.1. Supercomputer

1.8.2. Mainframe Computers

1.8.3. Minicomputers

1.8.4. Minicomputers and its Types

1.9.    Human Beings VS  Computer Systems

Summary of the Lesson

Self  Assessment Questions and Exercises

1.1 INTRODUCTION

Let us begin with the word ‘computer’ ,   which means ‘to calculate’. We all are familiar with calculations in our day life. We apply mathematical operations like addition, subtraction, multiplication, etc. and many other formulae for calculations. Simpler calculations take less but complex calculations take much  longer  time  Another factor is accuracy in calculations. So man

Explored the idea to develop a machine which can perform this type of arithmetic calculation faster and with full accuracy . This gave birth to a device or machine called ‘Computer’. 

Definition of Computer 

“A computer is an electronic  that operates under the control of instructions, that accepts the input data, processes or manipulates the given data according to the predefined instructions and stores the result for future use”.

 Figure 1.1: Components of a Computer

It can also retrieve the stored results as and when required again . Now-a-days, data is processed with the help of computer .this modern technique to process data is known as Electronic Data processing (EDP). Computer is also known as Electronic Data processing machine. 

The term data processing means:

 Ø Arithmetic and logical operations on data to get required results.

Ø To send and receive information from one location to another.

Ø Arranging data into a specific order etc.

1.2 HISTORICAL EVOLYTION OF COMPUTERS

 Man has developed from time to time various instruments to assist him in day-to-day for his data-processing needs. Depending upon the type of instruments used, the span of period has been split into  following ages:

·        Dark Age (5000 B.C.-1890 A.D.)

·        Middle Age (1890-1944 )

·        Modern Age (Since 1944 )

Basics of computer

Dark Age (5000 B.C.-1890 A.D.)

In this age all the computing devices were manual-mechanical in nature and all the earliest data processing equipment were all manual-mechanical devices. We refer to the era when these machines were user exclusively as the Dark Ages of data processing. This age introduced several devices such as Abacus, Napier’s bones, Pascal’s Calculator, etc.

Middle Age (1890-1944)

In the middle Age, all computing device were electro-mechanical in nature. In other words, these worked mechanically with the help of electricity. Examples include Hollerith’s Tabulating Machine’ Atanasoff  Berry Computer (ABC), etc.

Modern Age (Since1944)

Computer changed over time; they improved in speed, power and efficiency. Those changes are recognized as a progression of discoveries, each characterized by specific developments.

Mark I (1944)

Howard H. Aiken of Harvard University in  1937 designed a machine that could automatically perform a sequence of arithmetic operations and it was computer in 1944. It was named mark I. It was an electromechanical (relay)
 device, like the calculators which preceded it.

1.3 COMPUTER GENERATIONS

Each generation of computers is characterized by major technological development that fundamentally changed the way computer operate, resulting in increasingly smaller, cheaper, and more powerful and more efficient and reliable devices. Read about each generation and the developments that current devices that we use today.

The tam generation indicates the type of technology user in the computer construction. As new technology was emerging, it was being user in the

marking of computer. The new technology improved the speed, accuracy and storage capacity of the computers. Different technologies have been user for computers in different times.

Therefore, computers can be divided into five generation depending upon the technologies used.

These are:

1.     First Generation (1946-1959)

2.     Second Generation (1959-1965)

3.     Third Generation (1965-1971)

4.     Fourth Generation (1971-1985)

5.     Fifth Generation (1985-onwards)

1.3.1 First generation (1946-1959)

All subsequent computers after Mark I were all electronic. The early first-generation computers were powered by thousands of vacuum tubes. The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. A magnetic drum, also referred to as drum, is a metal cylinder coated with magnetic iron-oxide material on which data and programs can be stored. Magnetic drums were once use as a primary storage device but have since been implemented as auxiliary storage devices.

Figure 1.2: Vacuum Tubes

Examples:

• ·        Electronic Numerical Integrator and Calculator (ENIAC),
• ·        Electronic Discrete Variable Automatic Computer (EDVAC)
• ·        Electronic Delay Storage Automatic Computer (EDSAC)
• ·        UNIVAC I

·        

Characteristics of First Generation

 ·        Vacuum tubes

·        Magnetron tape and magnetic drum for external storage

·        Punched cards for input

·        Punched cards and paper for output

·        Machine and assembly languages

·        Human operators to set switches

·        Examples: UNIVAC I, UNIVAC II, Data Matic 100, EDSAC, Burrough 2202, etc.

1.3.2    Second Generation (1959-1965) 

 Transistors replaced vacuum tubes and ushered in the second generation computer. Transistor is a device composed of semiconductors material that amplifies a signal or opens or closes a circuit. Invented in 1947 at Bell Labs, transistors have become the Key ingredient of all digital circuits, including computers. Today’s latest microprocessor contains tens of millions of microscopic transistors.

Figure 1.3: Transistor 

Basics of computer

The first computers of this generation were developed for the atomic energy industry.

Characteristics of Second Generation

•        Transistors
•         Magnetic-Core Storage
•         Magnetic tape and magnetic disk for external storage
•         Punched cards and paper for output
•         High-level languages-FORTRAN, COBOL, PL/I, BASIC and others
•          Human operators to handle cards
•          Examples: Honeywell 200-, 400-, 800-series, IBM 7070/7080,CDC 1604, Burroughs B5000 series, etc.

1.3.3 Third Generation (1965-1971)

 During this time integrated circuits with transistors, resistors, and capacitors were etched onto a piece of silicon. This reduced the price and size of computers, adding to a general trend in the computer industry of miniaturization. The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.

Figure 1.4: Integrated Circuits

 Characteristics of Third Generation

·       Integrated circuits

·        Improved disk storage

·        Monitors and keyboards for input and output

·        More high-level languages, including RPG and Pascal 

·        First complete operating system meant less involvement for human operators

·        Family of computers introduced allowing compatibility

·        Minicomputers used commercially

·        Examples: IBM System/360,    IBM   System/370   Burrough/ 5700/6700, PDP-8 Series, PDP-11 Series, etc. 

1.3.4 Fourth Generation (1971-1985)

The microprocessor brought the fourth generation of computers, as thousands of integrated circuits we rebuilt onto a single silicon chip. A silicon chip contained a CPU. In the world of personal

computers,  the terms microprocessor and CPU are used interchangeably. At the heart of all personal computers and most workstations sits a microprocessor.

Figure 1.5: Microprocessor

 Microprocessors also control the logic of almost all digital devices, from clock radios to fuel-injection systems for automobiles.

Three basic characteristics differentiate microprocessors:

·         Instruction Set: The set of instructions that the microprocessor can execute.

·         Bandwidth: The number of bits processed in a single instruction.

·         Clock Speed: Given in megahertz (MHz), the clock speed determines how many instructions per second the processor can execute.

Characteristics of Fourth Generation

·         LSI and VLSI

·         Magnetic disk most common external storage

·         Introduction of microcomputers

·         Fourth-generation languages (4GLs) emerged and application software for microcomputers became popular

·         Microcomputers used-Compaq Deskpro 386

·         Typical examples: Burroughs B7700 and HP 3000 minicomputers

1.3.5 Fifth Generation (Beyond 1985 and till-date) 

The changes that have occurred since 1985 are plentiful. Computers have got tinier, more reliable, and many times faster. Computers are mostly built using components from many different corporations.

Computers have become more and more online orientated in modern times, especially with the development of the World Wide Web. Popular companies like Google and Yahoo! were started because of the internet.

Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. Artificial Intelligence is the branch of computer science concerned with making computers behave like humans. The term was coined in 1956 by John McCarthy at the Massachusetts Institute of Technology

Characteristics of Fifth Generation        

·         Development of true artificial intelligence

·         Development of Natural Language Processing

·         Advancement in Parallel Processing

       ·         Advancement in superconductor Technology     

Fifth generation computers are supposed to be the ideal computers. The scientists are working to design such computer that will have the following features.

1. Having their own thinking power
2. making decisions themselves
3. Having  capabilities of learning
4. Having capabilities of reasoning
5. Having large capacity of internal storage.
6. Having extra high processing speed
7. Having capabilities of parallel processing

1.4      MODEL OF DIGITAL COMPUTER 

Mod ern computer systems are  available  in numerous physical shapes and sizes, and truly speaking there is no end to it. In Computer System, different parts of a computer are organized in such a way that, it helps to perform various operations to complete the given specific task. A computer is a sort of electric brain, which capable to solve mathematical problems with in movements or produce desired information or a controlling order.