The Engineering Book: From the Catapult to the Curiosity Rover: 250 Milestones in the History of Engineering

1971

Microprocessor

Marcian Hoff (b. 1937), Federico Faggin (b. 1941), Stanley Mazor (b. 1941), Masatoshi Shima (b. 1943)

Without microprocessors, none of the things we take for granted today could exist: calculators, digital clocks/watches, remote controls, desktop computers, laptops, tablets, smart phones, HDTV, digital displays and keypads in microwaves, DVD players, dashboards, radios, thermostats, printers. Digital cameras could not exist, nor MP3 players, ECUs, etc. Every single thing around any normal person was mechanically controlled in 1969. The Saturn V rocket had a computer in it, sure. It was huge and cost millions.

Then in 1971, with the Intel 4004 chip’s arrival, everything started to change. This was the first microprocessor—the first time a single silicon chip held all of the circuits for a complete computer: Arithmetic Logic Unit (ALU), registers, memory addressing, instruction decoder. It was pathetic by today’s standards: roughly 2,000 transistors, 10 micrometer feature size, pMOS technology, 740,000 hertz clock, 8 or 16 clock cycles per instruction, 46 instructions. It could perform less than 100,000 instructions per second on 4-bit numbers. And yet at the time it was amazing that such a thing existed.

To make it, Intel’s engineers—including Marcian Hoff, Stanley Mazor, and Masatoshi Shima, and later, Federico Faggin—laid out the masks for the 2,300 transistors by hand using strips and rectangles of plastic.

Since then engineers have made so many advances. Four-bit registers moved to 64-bit. Feature size shrank from micrometers to nearly nanometers. Clock speeds from 740,000 hertz to 3,000,000,000. Transistor counts have gone from ~2,000 to billions. Not to mention all the conceptual improvements: floating point units, pipelining, multilevel cache memories, multiple cores, superscalar CPUs and hyperthreading, etc. Small microprocessors today cost pennies and use nearly zero power.

The microprocessor now touches every part of our lives. A typical car can have two dozen. A typical household many more. There will come a day when a microprocessor exceeds the power and complexity of the human brain. Engineers will have engineered their replacement.

Designer Federico Faggin points out the intricacies on an enlarged blueprint of the Intel 4004, which he helped design. It became the world’s first microprocessor in 1971.