Intel 4004

Intel

The Intel 4004 is generally considered the first microprocessor,^[6][7] and cost in the thousands of dollars.^[8] The first known advertisement for the 4004 is dated to November 1971; it appeared in Electronic News.^[9] The project that produced the 4004 originated in 1969, when Busicom, a Japanese calculator manufacturer, asked Intel to build a chipset for high-performance desktop calculators. Busicom original design called for a programmable chip set consisting of 7 different chips, three of them were used to make a special-purpose CPU with its program stored in ROM and its data stored in shift register read-write memory. Ted Hoff, the Intel engineer assigned to evaluate the project, believed the Busicom design could be simplified by using dynamic RAM storage for data, rather than shift register memory, and a more traditional general-purpose CPU architecture. Hoff came up with a four–chip architectural proposal: a ROM chip for storing the programs, a dynamic RAM chip for storing data, a simple I/O device and a 4-bit central processing unit (CPU), which he felt could be integrated into a single chip, although he was not a chip designer. This chip would later be called the 4004 microprocessor.

The architecture and specifications of the 4004 were the results of the interaction of Intel’s Hoff with Stanley Mazor, a software engineer reporting to Hoff, and with Busicom engineer Masatoshi Shima. In April 1970 Intel hired Federico Faggin to lead the design of the four-chip set. Faggin, who originally developed the silicon gate technology (SGT) in 1968 at Fairchild Semiconductor^[10] (and also designed the world’s first commercial integrated circuit using SGT – the Fairchild 3708), had the correct background to lead the project since it was the SGT to make possible the design of a CPU into a single chip with the proper speed, power dissipation and cost. Faggin also developed the new methodology for random logic design, based on silicon gate, that made the 4004 possible. Production units of the 4004 were first delivered to Busicom in March 1971, and shipped to other customers in late 1971.

Although the Intel 4004 is considered the first microprocessor, there were microprocessors embedded in industrial controllers. Some examples are automated gas pumps, traffic controllers, and flow meters.^{[citation needed]}