Computers the computers that have been appearing from years 40 have grouped in 5 generations, that are different by their components. Nevertheless the true revolution of computer science did not arrive until the appearance of the microprocessors. First generation the 1940-1960 University of Harvard establishes an agreement with the IBM company to create a computer of general character. This machine was operative in 1944 and had the capacity to store 72 numbers of 23 numbers, used punched cards to introduce the numbers and the operations. Its speed was not very high, needing ten seconds to realise a multiplication and eleven for a division E.N.I.A.C. First constructed computer totally electronic.
This machine occupied everything a cellar of the university, weighed 30 tons and required everything a conditioned air system, but he was able to conduct five thousand arithmetical operations in a second. John Von Neumann; their ideas were so fundamental that the father of the computers is considered. The fundamental idea of Neumann was to allow that in the memory data with instructions coexisted, so that the computer could be programmed through those data and not by means of wire that electrically the operations of the computer programmed. In this generation it is possible to emphasize the appearance of the first programming languages that allowed to replace the programming in Language Machine, that is to say 1 and 0, which they were introduced directly in the computer, by a Symbolic Programming, that translates symbols of the natural language to Language Machine. Second generation 1960-1965 is characterized by the change of the valve of emptiness by transistors and an increase of the storage capacity.
The circuits with transistors, reduce the size of the machines. The transistor is an electronics formed by a silicon crystal. Its operation is simple, has two possibilities, to transmit or not to transmit. Its appearance caused that the computers were faster small and cheap.