Tuesday 3 July 2012

COMPUTER GENERATIONS

      Each generation of computer is characterized by a major technological development that fundamentally changed the way computers operate, resulting in increasingly smaller, cheaper, more powerful and more efficient and reliable devices.

      The history of computer development is often referred to in reference to the different generations of computing devices. Each of the five generation of computers is characterized by a major technological development that fundamentally changed the way computers operate, resulting in increasingly smaller, cheaper, more powerful and more efficient and reliable devices. Learn about each generation and the developments that led to the current devices that we use today.

1st GENERATION COMPUTER (1945 -1955)

                  First generation computers are characterized by the use of vacuum tube logic.




 World War gave rise to numerous developments and started off the computer age. Electronic Numerical Integrator and Computer (ENIAC) was produced by a partnership between University of Pennsylvania and the US government. It consisted of 18,000vacuum tubes and 7000 resistors. It was developed by John Pres-per Eckert and John W.Mauchly and was a general purpose computer. "Von Neumann designed the Electronic Discrete Variable Automatic Computer (ED VAC) in 1945 with a memory to hold both a stored program as well as data." Von Neumann's computer allowed for all the computer functions to be controlled by a single source. Then in 1951 came the Universal Automatic Computer (UNI VAC I), designed by Remington rand and collectively owned by US census bureau and General Electric. UNI VAC amazingly predicted the winner of 1952, presidential elections, Dwight D.Eisenhower.In first generation computers, the operating instructions or programs were specifically built for the task for which computer was manufactured. The Machine language was the only way to tell these machines to perform the operations. There was great difficulty to program these computers and more when there were some malfunctions. First Generation computers used Vacuum tubes and magnetic drums (for data storage


ADVANTAGES:-
  •  THE first electronic computers were built during the Second World War to decrypt German coded  signals.                                                                                                                                 
  •       The advantages of the earliest computers are that they could perform thousands of calculations   each second, making it possible decodes messages in a useful time period (a few hours). 
  •      This was, pretty much, the only real advantage - the "father" of these computers (Alan Turing) had originally      planned these machines to try and prove mathematical conjectures, but this type of application couldn't be    considered until after the war. 


DISADVANTAGES:- 

  •           The disadvantages were many: they were very expensive, they contained thousands of valves (vacuum tubes) making them unreliable - although nowhere near as bad as feared, they had to be programmed in machine code.
  •       The major limitations for early computers were that memory was practically non-existent; only punched tape, delay line memory and mercury memory was available.