COMPUTER SOFTWARE

Software  refers to a program that makes the computer to do something meaningful. It is the planned, step-by-step instructions required to turn data into information. Software can be classified into two categories:

• System software

• Application software

           System software consists of general programs written for a computer.  These programs provide the environment to run the application programs.  System software comprises programs, which interact with the hardware at a very basic level.  They are the basic necessity of a computer system for its proper functioning.  System software serves as the interface between hardware and the user.  The operating system, compilers and utility programs are examples of system software.

              The most important type of system software is the operating system.  An operating system is an integrated set of specialized programs that is used to manage the overall operations of a computer.  It acts like an interface between the user, computer hardware and software.  Every computer must have an operating system to run other programs. DOS, unix, Linux and windows are some of the common operating systems

PARTS OF HARDWARE

THE PROCESSOR, more formally known as the central processing unit(CPU), has the electronic circuitry that manipulates input data into the information as required. The central processing unit actually executes comuter instructions.

MEMORY, form which the CPU fetches the instructions and data is called main memory. It is also called as primary memory and is volatile in nature.

OUTPUT DEVICES,show the rpocessed data-information-the result of processing. The devices are normally a monitor and printers.

STORAGE,usually means seondary storage, which stores data and programs. Here the data and rpograms are permanently stored for future use.
     The Hardware devices attached to the computer are called peripheral equipment. PERIPHERAL EQUIPMENT includes all input, output and secondary storage devices.

HARDWARE AND SOFTWARE

 

       A computer system has two major components, hardware and software. In practice, the term hardware refers to all the physical items associated with a computer system. Software is a set of instructions, which enables the hardware to perform a specific task.

                                                   COMPUTER HARDWARE

                             A computer is a machine that can be programmed to accept data(input) and process it into useful information(output). It also stores data for later resue(storage). The Processing si performed by the hardware. The computer hardware responsible for computing are mainly classified as follows:

                 INPUT DEVICES: allows the user to enter the program and data and send it to the rpocessing unit. The common input devices are keyboard, mouse and scanners.

FIFTH GENERATION-PRESENT AND BEYOND: ARTIFICIAL INTELLIGENCE

ARTIFICIAL INTELLIGENCE

     Fifth Generation computing devices, based on artificial intelliigence, are stil in their developmental stage. Fifth generation computers will come close to bridging the gap between computing and thinking.

FOURTH GENERATION 1971-PRESENT: MICROPROCESSORS

MICROPROCESSORS

      The microprocessor brought forth the fourth generation of computers, as thosusands of integrated circuits were built onto a single silicon chip. As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the internet

THRID GENERATION 1964-1971:INTEGRATED CIRCUITS

INTEGRATED CIRCUITS

      The development of the integrated circuit left its mark in the third generation of computers. Transistors were made smaller in size and placed on silicon chips, which dramatically increased the speed and efficiency of computers. In this generation, keyboards and monitors were used instead of punched cards and printouts. The computers were interfaced with an operating system which allowed to solve many problems at a time.

SECOND GENERATION-1956-1963

THE TRANSISTORS

The second generation of computers witnessed the vacuum tubes being replaced by transistors. The transistor was far superior to the vacuum tube, allowing computers to become smaller,faster,cheaper,energy-efficient and more reliable than their first-generation counter parts. The transistors also generated considerable heat that sometimes caused the computer to malfunction. But it was a vast improvement over the vacuum tube. Second-generation computers used punched cards for input and printouts for output.
    
     Second -generation computers moved form the used of machine language to assembly languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. The computers stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology.

GENERATION OF COMPUTERS

FIRST GENERATION -1940-1956: VACUUM TUBES

     The first generation of computers used vacuum tubes for circuirty and magnetic drums for memory. They were large in size, occupied a lot of spaceand produced enormous heat.

     They were very expensive to operate and consumed large amount of electricity. Sometimes the heat generated caused the computer to malfunction. First generation computers operated only on machine language. Input was based on punched cards and paper tabe, and output was displayed on printouts. First generation computers could solve only one problems at a time. 

1890AD- THE HOLLERITH TABULATING MACHINE

HOLLERITH TABULATING MACHINE

     A tabulating machine using punched cards was designed by herman hollerith and was called as the hollerith tabulating machine. This electronic machine is able to read the information on the punched cards and process it electronically.

1822AD-THE DIFFERENCE ENGINE

THE DIFFERENCE ENGINE

     The Difference Engine was built by charles babbage, British mathematician and engineer which mechanically calculated mathematical tables. Babbage is called the father of today's computer.

1642AD-THE ROTATING WHEEL CALCULATOR

THE ROTATING WHEEL CALCULATOR

     The Rotating Wheel Calculator was developed by a french philosopher, blasie pascal, using simple components such as gears and levers. This is a predecessor to today's electronic calculator. He was inspired by the computation work of this father's job and devised the model. He was only 19 years old, when he devised this model.

1633AD-THE SLIDE RULE

THE SLIDE RULE

     The slide rule invented by william oughtred. It is based on the principle that actual distance from the starting point of the rule is directly proportional to the logarithm of the numbers printed on the rule. The slide rule is embodied by the two sets of scales that are joined together, with a marginal space between them. The suitable alliance of two scales enabled the slide rule to perform multiplication and division by a method of addition and subtraction.

1614AD- THE NAPIER'S BONES

Napier's Bones

     The napier's bones was invented by john napier, a scottish mathematician as an aids to multiplication. A set of bones consisted of nine rods, one for each digit 1 through 9 and a constant rod for the digit '0'. A rod is similar to one column of a multiplication table.

EARLY HISTORY

2500BC- THE ABACUS

     Abacus is the first known calculating machine used for counting. It is made of beads strung on cords and is used for simple arithmetic calculations. The cords correspond to positions of decimal digits. The beads represents digits. Numbers are represented by beads close to the crossbar. Abacus was mainly used for addition and subtraction and later for division and multiplication.

HISTORY OF COMPUTERS

INTRODUCTION

   A computer is a tool annd partner in every sphere of human life and activity. Computers are bringing many changes in industry, goverrnment, education,medicine,scientific research,law,social service and even arts like music, movies and paintings. The areas of application of computers are confined onnly by the limitation on creativity and imagination.

     A computer is a electronic machine capable of performing basic operations like addition, subtraction, multiplication,division,etc. The computer is also capable of storing information,which can be used later.