On November 15, 1971, a tiny chip about the size of a baby's fingernail went on sale for $60. It was called the Intel 4004, and it was the world's first commercial microprocessor - a complete computer brain packed onto a single sliver of silicon. Before this, computers were room-sized monsters made of thousands of separate parts. Engineers at Intel had managed to squeeze 2,300 transistors onto one chip, and that chip could do 92,000 calculations every second. Big deal? It would change everything.
The 4004 was actually designed for a Japanese calculator company called Busicom. They had ordered twelve different custom chips for a fancy desk calculator. A young Intel engineer named Federico Faggin, along with Marcian Hoff and Stanley Mazor, suggested replacing all twelve with one programmable chip that could be used in different products. Busicom agreed, the chip worked, and Intel cleverly bought back the rights so they could sell it to anyone. That was the moment a sleepy memory-chip company turned into a tech giant.
The 4004 ran the very first electronic calculators, traffic lights, and even pinball machines. Within four years Intel had released much faster chips, and within ten years home computers like the Apple II and the IBM PC were appearing on kitchen tables. Today every smartphone, video game console, refrigerator with a screen, and self-driving car traces its family tree straight back to that little 1971 chip. The processor in your pocket is probably a billion times faster than the 4004 - but the 4004 is the great-great-grandparent of them all.
