40 years ago today, Intel Corporation introduced the 4004, the world's first commercially available microprocessor.
The 2,300 transistor device was made on a 10µm process in 1971 for Japanese calculator firm Busicom.
From there came the 8008, the 8080, and then the x86 processors that are still Intel's bread and butter today, and the influential Z80.
Federico Faggin designed the chip at Intel, from the architecture of Dr Ted Hoff and Stanley Mazor.
Dr Masatoshi Shima of Busicom wrote the functional description and designed its logic.
Read about the 4004 and the guys who developed it from the keyboard of Electronics Weekly's resident historian David Manners.
Faggin: Lust for life
Dr Federico Faggin designed not only the world's first microprocessor - the 4004 - but most of the famous early micros: the 8008, 8080 and Z80.
The Z80 is the world's most successful 8-bit microprocessor, selling over a billion devices and still shipping in quantities of forty million a year twenty years after its introduction. Faggin's 8080 architecture dominates today's computer industry via its most recent incarnations - Pentium and Pentium Pro.
Faggin is one of those unstoppable forces of nature: bubbly, ebullient, irrepressible. He's still working at the leading edge of technology... More
Shima: God's own job
The birth of the microprocessor, 25 years ago, followed an international conception between Intel of America and Busicom of Japan. But the story of the microprocessor's invention is usually told from the American point of view.
Dr Masatoshi Shima was one of the Busicom team which went over to Santa Clara in June 1969 to commission Intel to produce a set of chips for a calculator. The resulting chip-set, architected by Dr Ted Hoff, became known as the 4000 chip family of which the fourth, the famous 4004, was the world's first microprocessor.
Shima wrote the functional description of the 4004 and designed its logic. Later he was recruited by Intel to write the functional specification and to do the design of the 8080. Shima then left Intel with Zilog founder Federico Faggin to design the Z80 and Z8000. Later still, he left Zilog to go back to Intel to head up the company's first design centre in Japan. More