11.9.2 - THE ANALYTICAL CALCULATOR CONCEPT

In 1823, the British mathematician Charles Babbage developed the concept of the difference engine considered as the forerunner of the modern digital computer.
In reality it was a special-purpose calculator to help the Bristih navy draw up various nautical tables. These could be tables of multiplication, logarithms, sines, and cosines, or physical measurement and observations.
Later on the Babbage developed the analytical engine that was conceived as a general-purpose computer comprising: the memory for data storage entered by punch cards; it was responsible to supply the necessary instructions for the machine to execute all the arithmetical operations using a ten-digit recorder, as well as the processing unit, that allows the delivering of printed output.
It it interesting to notice that Babbage has taken the idea of punched cards from Joseph Marie Jacquard, who invented an attachment to the loom in 1805.
Around 1848, the British logician, George Boole developed the theory of the symbolic logic describing the possibility to express logic in very simple algebraic systems giving birth of the Boolean algebra, which has only 0 and 1 as an answer in numerical terms.
Thus the modern computers can make use of this binary system, with their logic parts carrying out binary operations.
In 1890, William S. Burroughs invented the adding and listing machine using punched cards. The same principle was used by Herman Hollerith to help in solving the compilation problems arising during the 1890 United States demographic census.
At the end of XIX century the concept of the analog computer had been done by researches of James and William Thomson later as known as Lord Kelvin. They were responsible for the design of the planimeter, an apparatus comprising a ball and a disk integrator. Lord Kelvin used this integrator in a harmonic analyser as well as a tide predictor.
Unlike digital computers, which started out as simple mechanical devices and then went through a brief electromechanical period during the later thirties, finally becoming an electronic machine in 1940 only. In this way as a historical and technical approach the development of the electronic computer will be commented considering several upgrading stages also known as families or computers generations.