COMPUTER GENERATIONS

CHARLESS BABBAGE 

(Father of Computers): - An English man laid the foundation stone of modern computer science; in “1821” he designed Difference Engine. He also planned another machine namely Analytical Engine but it could not completed due to lack of funds.

In 1880 “Dr. Herman Hallerith” developed Punched Cards to store programs. In 1946 the electronic computers was developed by “J.P. ECKERTT” and “J.W. MANCHLY” called as (ENIAC) “Electronic Numeric Integrator and Calculator”. It could perform 5000 additions and 400 multiplications a second.

COMPUTER GENERATIONS

Computers are often grouped in categories known as Computer Generations. Various Generations of computers and their predominant features is given below.

1.         FIRST GENERATION (1949 - 1955): - 

           These computers used “Vacuum Tubes” as the main electronic element and magnetic drum as the main electronic memory. Programming had to be done in Machine or Assembly Language only. These computers were physically large generated significant heat and the speed of operations was in terms of Milli Seconds. (I.e. Thousandth of a Second).

2.         SECOND GENERATION (1956 – 1965): - 

            In the second generation of computers “Transistors” replaced vacuum tubes as the basic Electronic element. These transistorized computers were work faster, more compact and reliable.  The speed of operations was in terms of Micro Second (i.e. Millionth of a Second). The Magnetic Core was introduced as the main memory. Magnetic tapes and disks were used for storage of bulk data. In the area of software, compilers were introduced; they’re by enabling the programmers to write programs in High-level Languages. Some examples as such computers are IBM- 1401, HONEY WELL – 800 and IBM – 1620.

3.         THIRD GENERATION (1966 – 1975): - 

           The Introduction of the IBM – 360 series of computers in 1965 marked the beginning of this generation. Monolithic ‘Integrated Circuits’ were replaced Transistors.  This reduced the size further and improved the speed of computers in terms of Microseconds.  In this generations that Operating Systems (OS) were introduced.

4.         FORTH GENERATION (1975 – Onwards): - 

          In this generation of computers, significant developments emerged, both in hardware and software. Semi conductor memory replaced the core memory, which enabled the achievement of higher speeds at lower cost. The introduction of Micro Programmed logic permitted the machine logic to be altered to suit the user’s needs. The processing speed of computers is in Nano-Seconds (i.e.Billionth of a Second).

5.         FIFTH GENERATION: - 

               This generation represents more technological developments both in Hardware and Software areas. Fifth generation computers are aimed specifically at Artificial Intelligence (A.I) Applications.

THE COMPONENTS OF COMPUTERS

 The unit that resembles a T.V. screen is called the “Monitor”, or more commonly, the VDU, an abbreviation of Visual Display Unit.:. The component that closely reassembles a type writer is called “Key Board” 7 .Which is used to print the results of any operations at on paper is called “Printer”6. The Tiny devised connect to the system unit through a cord resembling a tail is called a “Mouse” 8.moving the mouse produces a corresponding movement of an arrowhead on the VDU. The box like structure on which the monitor usually rests is called “CPU”5 or System Unit. “CPU” is used to processing data and calculating purpose. These devices are collectively referred to as the hardware. Thus hard ware comprises all the physical components of a P.C. (Personal Computer) system.

BASIC PRINCIPLES OF COMPUTER

INPUT                         PROCESSING                        OUTPUT

A Computer can be accept data, process it and supply the results. These forms the “Input” based on which a computer will perform some “Process” and “Output” the result. This is called I.P.O. (Input – Processing – Output) cycle is an essential concept for under standing the working of any computerized system.

The hardware consists of the physical components and the software is the set of instructions. The major hardware components of a computer are divided in 3 types.

1.         INPUT DEVICES (or) INPUT UNITS

2.         CENTRAL PROCESSING UNIT (C.P.U)

3.         OUTPUT DEVICES (or) OUTPUT UNITS