Until this point, computers were built using vacuum tubes, which were devices capable of amplifying electronic signals. However, the size and number of these vacuum tubes required computers to be so big that they filled entire rooms, and also meant that they consumed huge amounts of power. This made computers expensive and impractical for general use. The goal of these three innovators at Bell Labs was to eradicate the need for vacuum tubes by switching to semiconductors, thereby shrinking computers and making them much more efficient.