Why it was needed
Vacuum tubes worked, but they were big, hot, power-hungry and burned out. Bell Labs was looking for a replacement for telephone networks. Bardeen and Brattain built a germanium point-contact transistor in December 1947; Shockley then designed the more reliable junction transistor.
How it works
A transistor has three terminals. A small voltage or current on one of them controls a large current between the other two. So it can act as an amplifier (radio) or a switch that is either on or off. That is exactly what digital logic needs: ones and zeros.
From radio to processor
- 1947First point-contact transistor at Bell Labs
- 1954First silicon transistor (Texas Instruments) and the transistor radio
- 1959The MOSFET, today the most manufactured device in history
- 1971Intel 4004 with 2,300 transistors
- 2020sChips with tens to hundreds of billions of transistors