---
title: Transistor and Microchip
tags: [hardware, transistor, integrated-circuit, moores-law]
status: active
confidence: high
created: 2026-04-09
sources:
  - file: public-domain/riordan-hoddeson-crystal-fire.txt
    hash: placeholder
    size: 0
    ingested: 2026-04-09
aliases: []
---

# Transistor and Microchip

The transistor and the integrated circuit are the twin inventions that made modern computing physically possible. Without them, [[von-neumann-architecture]] computers would remain room-sized vacuum-tube machines consuming megawatts of power.

## The Transistor (1947)

John Bardeen, Walter Brattain, and William Shockley at Bell Labs demonstrated the first point-contact transistor on 16 December 1947. The transistor is a semiconductor device that amplifies or switches electrical signals. Unlike vacuum tubes, transistors are small, reliable, consume little power, and generate minimal heat. Bardeen, Brattain, and Shockley shared the 1956 Nobel Prize in Physics for the discovery.

## The Integrated Circuit (1958–1959)

Jack Kilby at Texas Instruments (1958) and Robert Noyce at Fairchild Semiconductor (1959) independently invented the integrated circuit — multiple transistors and their connections fabricated on a single piece of semiconductor. Kilby won the Nobel Prize in Physics in 2000; Noyce had died in 1990. The IC eliminated the "tyranny of numbers": hand-soldering thousands of discrete transistors was slow, expensive, and unreliable.

## Intel 4004 and the Microprocessor (1971)

Intel's 4004, designed by Federico Faggin, Ted Hoff, and Stanley Mazor, placed a complete CPU on a single chip for the first time. The 4004 contained 2,300 transistors and ran at 740 kHz. It was designed for a Japanese calculator company, but Intel recognised it as a general-purpose computing engine. The microprocessor made the [[personal-computer-revolution]] economically viable.

## Moore's Law

Gordon Moore, Intel co-founder, observed in 1965 that the number of transistors on a chip doubled roughly every two years at constant cost. This empirical trend held for over 50 years, driving exponential improvements in computing power and reductions in cost. Modern chips contain tens of billions of transistors at nanometre scales.

## Physical Limits

By the 2010s, transistors approached atomic dimensions. Classical scaling slowed, prompting the industry to pursue 3D chip stacking, chiplets, and specialised processors (GPUs, TPUs, NPUs) to continue performance improvements. The end of Moore's Law has accelerated interest in quantum computing and neuromorphic architectures.

See also: [[von-neumann-architecture]] for the logical design these chips implement; [[programming-languages-overview]] for the software abstraction layers above the hardware.
