There was a time when valves were dominating the technology of electronic equipments, whether they were telecommunication equipments or the first electronic processors. At that time each device had his own individuality and anyone could easily understand its functioning from its external aspect, once they had opened its package. The functioning of an old radio set could be simply understood by examining its type, connections and the specific devices hidden inside it – valves, but also resistors, capacitors or else.

Things started to change with the invention of transistor in 1947. Transistor did not only solve problems of reliability, space and consumption, but it was suitable for “integration”, that means to apply on only one substrate of semiconducting material, many devices, or entire and identical circuits, thus reducing size, losses and risk of damage. The electronic calculation was based from the beginning on the large scale repetition of similar circuits, whose different tasks would have been programmed in a following moment: the newly born computer science developed massively the integration technology, using “chips” of identical units, and so became very quickly an important economical and social event, as it had occurred fifty years before with radio broadcasting. Whether it is conscious or not, it is the same method used by our brain, where neurons form systems, then systems of systems, and so on...

With the appearance of LSI - Large Scale Integration - systems, computer science, already launched by the gift of the invention of transistor, started to return the favour to telecommunications. At first computers were used in telephone switches to replace the bulky electromechanical equipments, later they started the transformation of transmission from analogical into numerical. All this was accelerated by the invention of microprocessors and distributed computing. At this point telecommunications too became massive consumers of numerical integrated circuits and the Silicon age triumphed.

Immediate consequence is that now the same technological base is used in calculation as well as in telecommunication and all the other ICT applications. If the chemistry of Carbon dominates within all the living things, Silicon dominates the world of artificial equipments operating on information.

(Gabriele Falciasecca)

 

entry Transistor in the Treccani Encyclopedia