Robert Noyce And The Road To El Dorado
Why the inventor of the silicon chip deserves more credit for the microprocessor
“Noyce knew exactly what he possessed in this integrated circuit, or microchip, as the press would call it. Noyce knew that he had discovered the road to El Dorado.”
Tom Wolfe: The tinkerings of Robert Noyce
“Don't be encumbered by history, just go out and do something wonderful.”
Robert Noyce
The story of the Intel 4004 has been the subject of much debate. Was the 4004 the first microprocessor? What was innovative in its development? Who deserves credit?
The 4004 was a success despite major missteps. It succeeded because of the determination of a small group of engineers. But it also succeeded because of Robert Noyce.
Noyce and Gordon Moore founded Intel in 1968. Noyce had invented the monolithic silicon integrated circuit, or “silicon chip”, whilst at Fairchild Semiconductor. Moore was already famous as the author of Moore’s Law, his prediction that the complexity of semiconductor components for a given cost would roughly double every year1.
Their strategy at Intel was to design and manufacture advanced integrated circuits in large volumes. Initially, this meant memory chips for the makers of mainframe and mini computers.
The story of the 4004 began when Noyce was visiting Japan in April 1969. He was approached by Busicom, a small but ambitious manufacturer of calculators. Busicom had designs for several complex chips (at least seven) that together would power a new range of desktop calculators. Could Intel, with its leading manufacturing technology, make them?
Noyce assigned Marcian ‘Ted’ Hoff to liaise with Busicom. Hoff soon saw that producing the Busicom designs would be an unattractive business for Intel. He started to develop the outline of an alternative: a design based on a smaller number of chips that could be reprogrammed to perform other tasks. Joined by Stan Mazor, the two worked to confirm that the new designs could meet Busicom’s requirements. The approach was simple enough that Hoff believed that all the main control functions of the computer could be incorporated into a single chip. That chip would become known as a microprocessor.
Noyce encouraged Hoff to continue developing his ideas. Noyce estimated that each set of the original Busicom chip designs would cost over $300 to make. He wrote to Yoshio Kojima, the President of Busicom. Soon the Intel alternative was presented to Busicom.
After considerable debate Intel persuaded Busicom’s management, on a visit to California, to adopt the new design. The contract was signed in October 1970 and the Busicom team headed home. Intel would make 60,000 sets of the new designs for a price of $60 each. Disappointingly for Hoff though, Busicom would keep exclusive rights to the new Intel design.
But Intel’s manufacturing teams were struggling so a new project would not be popular. Noyce visited operations director Andy Grove. Sitting on the corner of Grove’s desk, Noyce casually announced “We’re starting another project.” Grove wasn’t happy but the project continued.
Except it didn’t. No significant further work was done on the project for six months. Hoff moved on to other projects. Intel simply didn’t have anyone who could turn his outline designs into working silicon.
So when Federico Faggin, a young Italian engineer, arrived at Intel in April 1971 he found little more than Hoff’s outline. Faggin was recruited from Fairchild with the vague promise that he would be working on a project with ‘lots of logic’. Initially, delighted at the prospect of working on such an ambitious design, he was less happy when he learned about the state of the project. ”After one day on the project, I was six months behind.”
To make matters worse, a Busicom engineer, Masatoshi Shima, was arriving from Japan the next day. Faggin met Shima at the airport and drove him to Intel’s offices before showing him what he had on the new designs.
This was not what Shima expected. "I came here to check. No good. This is just idea. You bad. You late." Over the next few days, Faggin calmed Shima down, explained the situation and then persuaded his visitor to stay and help deliver the project.
Faggin was an ideal choice for the project. Whilst at Fairchild, he had developed silicon gate technology, which would be needed to build the new designs. He also understood computer architecture, having previously developed a computer for Olivetti in Italy.
Working with Shima and Mazor, Faggin started developing the four chips. One chip handled communication with the calculator’s keyboard, printer and display. Two more were memories. Finally, and by far the most complex, there was the microprocessor.
The development process included laying out the design of the chips by hand on large sheets of ruby-red Rubylith. Noyce would wander into the layout room, cigarettes in hand, and join Shima in checking the layout.
The designs went to manufacturing. The first wafer containing the most demanding of the four chips, the microprocessor, arrived on Faggin’s desk in December 1970.
He placed the wafer on his test equipment. First chip: no response. Second chip: no response. And so on. Finally, and with a degree of relief, he realised that Intel’s manufacturing team had omitted one essential stage in the manufacturing process.
A second, corrected, set of wafer samples arrived in January 1971. They worked the first time with just some small bugs to fix. By March the chips started production and shipping to Japan.
Then in May, in a telephone call with Shima, Faggin discovered that Busicom was in financial difficulties. Sensing an opportunity, Faggin and Hoff persuaded Intel’s management to buy some of the rights to the designs. Intel would now be able to sell the microprocessor and the other chips for use in devices other than calculators.
Faggin decided that the chips should be named to emphasise that the four were designed to work together. They became the 4001, 4002, 4003 and - the microprocessor - the 4004.
Intel launched the new chips with a double-page press advertisement in November 1971. The portentous headline ‘Announcing a new era in integrated electronics’ was, for once, justified.
The 4004 soon found its way into cash registers, pinball machines and more. It wasn’t a huge commercial success but it established Intel as the early leader in microprocessors. The 4004 team, led by Faggin, iterated first with an enhanced 4004, the 4040, and then with much more capable designs, the 8008 and then the 8080. The 8080 would eventually be extended and enhanced to become the design that powers the majority of personal computers and servers today.
The 4004 was a team effort. It wouldn’t exist without Hoff’s original idea, Ma Shima’s skills or Faggin’s hard work, drive and expertise in silicon gate technology.
And crucially, it wouldn’t have existed without Noyce. His creation of Intel. His original contact with Busicom. The encouragement he gave to Hoff to pursue his ideas. His visits to the layout room. His instructions to Andy Grove. Above all his vision for Intel and his determination to take risks to achieve that vision. One step on the road to El Dorado.
Notes And Further Reading
So many words have been written about the 4004 in the fifty years since it was launched that I hesitated to add any more. Although mine is not a unique perspective, Noyce’s contribution is often minimised or omitted.
For a slightly more extensive account. I’d recommend the IEEE Article:
https://spectrum.ieee.org/chip-hall-of-fame-intel-4004-microprocessor
The recording of the thirty-fifth anniversary of the 4004 event at the Computer History Museum is essential viewing. Faggin’s grasp of the detail thirty-five years on is very impressive as is the fact that he gives credit, by name, to a number of the 4004 team.
Finally, for a short portrait of Noyce from an outstanding writer, Tom Wolfe’s Tinkerings of Robert Noyce is a great read.
https://web.stanford.edu/class/e145/2007_fall/materials/noyce.html
Photo Credits
Robert Noyce and Gordon Moore:
By Intel Free Press:
https://www.flickr.com/photos/intelfreepress/8268686452/sizes/o/in/photostream/,
CC BY-SA 2.0:
https://commons.wikimedia.org/w/index.php?curid=27929328
Moore would later revise his prediction to a doubling every two years.
Robert Noyce is such a special person!