Presentation By Jaspreet Rekhi Introducing Sites: - www.rhombnet.com www.ppt.rhombnet.com www.wallpapers.rhombnet.com

Evolution of Computers and Computer Generations

ABACUS 4th Century B.C. The abacus, a simple counting aid, invented in Babylonia (now Iraq) in the fourth century B.C. This device allows users to make computations using a system of sliding beads arranged on a rack.

BLAISE PASCAL In 1642, the French mathematician and philosopher Blaise Pascal invented a calculating device that would come to be called the "Adding Machine".

Pascal's mechanical Adding Machine automated the process of calculation. Although slow by modern standards, this machine did provide a fair degree of accuracy and speed. Barren Gotterfried Wilhelm invented the first machine for multiplication

Charles Babbage Invented Difference Engine for producing reliable tables to support mathematical and statistical data Then he produced a new idea of an Analytical Engine for faster processing of arithmetic operations Analytical Engine was capable of performing 60 additions per minute But he was unable to produce working model of this engine

Some Well Known Early Computers The Mark I Computer (1937-44) Designed by Howard A. Aiken, Professor of Harvard University in collaboration with IBM Corporation Automatic Sequence Controlled calculator First fully automatic machine Electromechanical device (both electrical & mechanical) Complex in design and huge in size Used over 3000 electrical switches, approximately 50 feet long and 8 feet high Performed 5 basic arithmetic operations: addition, subtraction, multiplication, division and table reference

The Atanasoff-Berry Computer (1939-42) Designed by Dr. John Atanasoff and his assistant Clifford Berry An electronic machine to solve mathematical equations Used 45 vacuum tubes for internal logic and capacitors for storage The ENIAC (1943-46) Electronic Numerical Integrator and Calculator Designed by a team of people at Moore School of Engineering, U.S.A Team led by Professors J. Presper Eckert & John Mauchly First electronic computer Developed because of military needs to solve ballistic related problems Used 18000 vacuum tubes Could add and multiply two numbers in 200 and 2000 microsec respectively Programs were wired on board and hence couldn’t be changed

The EDVAC (1946-52) Electronic Discrete Variable Automatic Computer Designed by Von Neumann Used concept of stored program in the computer memory so that they can be changed as and when required Von Neumann also introduced concept of storing both instructions in binary form EDSAC (1947-49) Electronic Delay Storage Automatic Calculator Designed by group of scientists lead by Professor Maurice Wilkes Designed at Cambridge University Mathematical Laboratory Executed its first program in May 1949 Addition & multiplication took 1500 & 4000 microseconds respectively

The UNIVAC I (1951) Universal Automatic Computer First Digital Computer First UNIVAC machine was installed in Census Bureau and was continuously used for 10 years First business use in 1954 by General Electric Corporation

Computer Generations First Generation (1942-1955) Second Generation (1955-1964) Third Generation (1964-1975) Fourth Generation (1975-1989) Fifth Generation (1989-Present)

First Generation Used thousand of vacuum tubes They were fastest calculating devices. Too large in size Data & instructions were fed with the help of punched cards Instructions were written in machine or assembly level language Large amount of heat due to thousands of vacuum tubes, so air conditioning was required High power consumption

Frequent hardware failure due to burn out of tubes Costly to manufacture and maintain these computers The first computer prototype using vacuum tubes was ENIAC

Second Generation Use of transistors instead of vacuum tubes Invented by John Bardeen, William Shockley and Walter Brattain Invented at Bell Laboratories, USA in 1947 Easier to use and handle No burning out, but hardware failures were still there Almost ten times faster than tubes Consumed almost one-tenth the power consumed by tubes

Much smaller in size Less expensive to produce but still costlier Produce less heat as compared to tubes but air conditioning was required Magnetic disk and magnetic tapes were used as memory High level programming languages such as FORTRAN, COBOL were used Easier to program these computers Batch operating system was used

Third Generation In 1958, Jack St. Clair Cilby & Robert Noyce invented integrated circuits IC’s consist of several electric components like transistors, resistors and capacitors embedded on a single chip of silicon SSI, MSI technology More powerful & faster than second generation computers (could perform 1million instructions/sec) Smaller in size and hence require small space for installation Require less power and produce less heat but still need proper air conditioning

More reliable and very less prone to hardware failure Faster and large memory as compared to second generation computers Were less costlier and easy to manufacture and maintain Time sharing operating system allowed use of single computer by multiple users

Fourth Generation Use of IC’s with VLSI technology Microprocessors and semiconductor memory Larger memory because of larger hard disks and floppy disks and magnetic tapes as portable storage media Very less heat hence no air conditioning was required instead fans were used Graphical User Interface operating systems were used Very easy to manufacture & maintain them and cost very less Very fast as compared to computers in early generations

Fifth Generation IC’s based on ULSI technology Portable PC’s (notebook computers) were much smaller and handy than fourth generation computers Much faster and powerful than computers in earlier generations Consume very less power Hot plug technology Less costlier and easy to manufacture and maintain Newer and more powerful applications make computers more easy to use in every field

Thanks for downloading…… Do Comment plz……. By : - Jaspreet Rekhi www.rhombnet.com www.ppt.rhombnet.com