I was not so excited when the 4004 became functional,
but when the 4004 worked as the engine for a calculator with my program,
I was very excited and happy, because my responsibility was to develop a calculator. Masatoshi Shima
Intel’s 4004 microprocessor was not the culmination of the pursuit of a dream or a breakthrough moment. It was the result of a simple ‘work-around’.
Busicom, a Japanese calculator company, endeavoured to reduce its production costs and devised a calculator based on integrated circuits. The design called for twelve ICs and Busicom approached Intel, a new operation that had been running for a year. They were tasked to develop a design and produce 60,000 sets over three years.
Intel had signed another custom-chip project for the CTC Datapoint 2200 terminal. This required a total of one hundred transistor-transistor logic components to be integrated into a handful of chips.
Ted Hoff defined the approach for both proposals, concluding it would be easier if both designs were a single chip and believing this would not prove more complex than current memory chips. Together with Stan Mazor he prepared the specification.
Federico Faggin was hired as team leader to develop one of the chips. Born in Italy, Faggin had developed his own computer at 19, worked at Olivetti and Fairchild in Italy and California where he developed the Fairchild 3708 MOS silicon-gate IC.
1970 Faggin had been at Intel for two days when Masatoshi Shima, the Busicom engineer developing the calculator firmware, arrived. Shima planned a short trip to check progress and was shocked to find little; he stayed for seven months to drive the project forward.
Faggin and Shima completed what became the 4004 by November 1971 – the very first microprocessor on a single-chip in production.
The development would have been owned by Busicom, but the company was strapped for cash and asked Intel to reduce the price. Busicom allowed Intel to achieve volume by selling the product to others. Busicom was bankrupt by 1974.
The resultant 4004 had the equivalent of 2,300 transistors, capable of 60,000 transactions/second; documentation was produced by Adam Osborne. On the original 4004, Federico Faggin etched the initials FF into its design, rather like a painter autographing masterpieces.
1974 As soon as it was introduced the 4004 was updated to become the Intel 4040 with 3,000 transistors, working at the same speeds.
The 1201 chip developed by Intel for the Datapoint 2200 task was rejected by CTC, but they approved Intel marketing this chip as its own. Released in April 1972, this was renamed the Intel 8008. 8008 was a 16-pin device with 3,500 transistors, a tad slower than the 4004/4040 but working with eight bits at a time restored its speed advantage, addressing more memory and components. Masatoshi Shima was hired by Intel to upgrade this to the 8080 – by 1974.
The 8080 inspired design engineers to apply the microprocessor to a raft of products – Micral, Scelbi’s 8H, the Mark-8, the Altair…
1990 there was a furore when the US patent office awarded Gilbert Hyatt the patent for the single-chip microprocessor. Hyatt said he had developed an MPU back in 1968 for a machine tool controller. He believed he was due millions from semiconductor manufacturers ‘This will set history straight. And this will encourage inventors to stick to their inventions when they’re up against the big companies.’
1996 Texas Instruments overturned the decision, Hyatt’s device had never been implemented; capabilities then meant it was impossible.