History and Evolution of computers,Electronic computer
Need is the mother of invention. Because computers are evolved as result of man's continues research for finding Fast and accurate calculating devices.The effort are still continuing to make machine more and more versatile
The stone age used pebbles for counting. /later on when man become more civilized, Abacus cam in use. Abacus seems to be the earliest calculating machine , which was developed by Chinese 3000 years ago. Al thought the Abacus was invented around 600 BC, it is still used in the Far East and its users can do calculations at an amazing speed
another manual calculating device was John Napier's Bone or Cardboard Multiplication calculator. john Napier, the 17 the century mathematician, devised a set of rods for use in calculators involving multiplication. These Rods were carved from bones and therefore called Napier's Bones.
The first adding machine was invented by a French Mathematician Blase pascal
in 1642. His machine was a simple calculator used for addition and substraction purposes.This machine was later modified By a German, Gottfriend Lebnnitz, in 1671.This was the first machine to multiply and divide directly.
Charles Babbage, a 19th century at Cambridge University, is considered to be the father of the modern digital computers.Babbage made a calculating machine called Different Engine in the year 1822 which could evaluate accurately algebraic expressions and mathematical tables correct up to 20 decimal places.In 1842 Babbage came out with his new idea of analytical engine that was intended to be completely automatic.
Electronic Computers
A mechanical computer has two drawbacks.
- Computing speed is limited by the inertia of its moving parts
- The transimission of digital information by mechanical means is quite unreliable
by
The electronic computer moving parts are electronic device such as the
Vacuumtube or electronic valve, which was developed in the early 1900's, permit the processin and storage of digital signals at speeds far exceeding those of any mechanical devise
We will now discuss some of the well known early electronic computers.
- The Mark 1 computers(1937-44)
- The ENIAC computers(1943-46)
- The EDVAC computers(1949-52)
- The EDSAC computers(1947-49)
- The UNIVAC computers(1951)
Mark 1 computers(1937-44)
Mark 1 was the fully fully automatic calculating machine designed by Howard A Aiken of Hardvard University in collaboration with International Business Mechanism(IBM) corporation. Its design was based on the technique already developed for punched card Machnery. Al thought this this machine proved to be extremely reliable, It was very complex in design and huge in size. It used over 3000 electrical switches to control its operation and was approximately 50 feet long and 8 feet high. it was capable of performing five basic arithatic operation :
Addition,Subtraction, multiplication,division and table reference
A number as big as 23 decimal digits could be used in this machine.It took approximately 0.3 second to add two numbers and 4.5 second for multiplication of two numbers. It was basically an electro mechanical device since both mechanical and electronic components were used in its design.
ENIAC-(Electronic Integrator And Calculator) computers
(1943-46)
The Electronic Integrator And Calculator was the first fully electronic computer.this mechine was designed and compiled in 1946 by J P Eckert and J M Mauchly at the moore school of Electronic Engineering at the university of pennsylvania, USA. ENIAC was developed for military nedd. It was the first fast machine as compared to its ancestors.
The addition of two numbers was achieved in 200 microseconds, and multiplication in 2000 microseconds.The ENICA has 30 tons and containing more than 18000 vacuum tubes.The ENIAC computer is faster than Mark 1 computer and now microcomputers are 5000 times faster than ENIAC computers.
EDVAC-(Electronic Discrete Variable Automatic Computers) computers(1949-52)
The Electronic Discrete Variable Automatic Computers(EDVAC) was the first computer that was designed on stored programs concept.
Developed by Dr. John Von Neumann. The basic idea behind the stored program concept is that a sequence of instructions as well as data can be stored in the memory of the computer for the purpose of automatically directing the flow of operations.The stored program concept allows much faster operation since the computer has rapid access to both program and data.
The other advantages of stored programs is the logical decision can tack internally. The stored program feature considerably influenced the development of modern digital computers and because of the feature, modern digital computers are often called stored program digital computes
EDSAC -(Electronic delay storage automaic Calculator)computers(1947-49)
Almost simultaneously with EDVAC of USA , the britishers developed the Electronic delay storage automaic Calculator (EDSAC). In EDSAC additon operation was accomplished in 1500 microsecconds. This machine was developed by a group of scientists headed by professor Maurice Wilkes at Cambridge university Mathmatical Laboratory.
UNIVAC-(Universal Automatic Computer) computers(1951)
Universal Automatic Computer (UNIVAC) was the first digital computer. It was produced in 1951 by Universal Accounting Company set up by Eckert and Mauchly. This machine used magnetic medium for data input and output.
