1971

First Microprocessor

Federico Faggin (b. 1941), Ted Hoff (b. 1937), Stanley Mazor (b. 1941)

Intel was founded in July 1968 with $2.5 million in funding from a venture capitalist to build integrated circuits. The company’s first chip was the 1101 memory chip; it stored 256 bits of memory and did not sell well. The second chip, the 1103, stored 1024 bits and was hugely successful, taking the company public in 1971.

That same year, Intel introduced the 4004, the world’s first general-purpose computer on a chip. It was designed by Federico Faggin, Ted Hoff, and Stanley Mazor and had 2,300 transistors.

Modern computers are based on von Neumann architecture, credited to mathematician and physicist John von Neumann in the 1940s. The computer has an arithmetic logic unit that can perform basic math (addition and subtraction), a few fast memory cells called registers, logic that can fetch data and instructions from memory, and other logic that can store data back to memory. A special register called the program counter (PC) points to a specific location in the computer’s memory bank. The computer operates by reading an instruction from the memory location specified by the PC, executing it, incrementing the PC so that it points to the next memory location, and then repeating. The 4004 marked the first time all of these functions were combined on a single piece of silicon. The 4004 had 16 4-bit registers and 45 instructions, kept its program in 4,096 bytes of read-only memory, and could address another 1,280 words of 4-bit RAM.

The 4004’s word size was just 4 bits—enough to store the numbers “0” through “9” coded as binary. Not surprisingly, the 4004 was designed for use in a calculator. But because it was general purpose, the chip could be used in other applications. For example, one company used the 4004 to control a pinball machine.

Five months later, Intel brought out an 8-bit version of the device called the 8008, which could address up to 16,384 bytes of memory and intermix programs and data. In April 1974, the company released the 8080, which could address up to 65,536 bytes of memory. Despite the differences, all versions used the same basic assembler code—a code that would later be shared with Intel’s Pentium® and Core® processors.

Federico Faggin stands before an enlarged blueprint of the Intel 4004, which he designed and which became the world’s first microprocessor.