The transistor was invited in 1947 by Wiliam Shockley, John Bardeen and Walter Brattain. At first the transistor was used only as an amplifier. Some time later it was detected as a fast electrical switch. In the beginning of the 50s the transistor was produced in masses. The military purchased most of the transistors.

The transistor was composed of tiny slivers of crystals from the element silicon. These crystals were classified as semiconductors because electrical current could pass through the crystals in one direction but not in the other. Bardeen dicovered an inhibiting effect which existed on the surface of the crystal and this was interfering with the flow of electrical current.

The transistor succeeded where the vacuum tube had failed. The transistor was smaller, generated less heat, and wouldn't burn out.