<Li> 16 - pin DIP </Li> <P> The Intel 4004 is a 4 - bit central processing unit (CPU) released by Intel Corporation in 1971 . It was the first commercially available microprocessor by Intel . The 4004 was the first in a long line of Intel CPUs . </P> <P> The chip design started in April 1970, when Federico Faggin joined Intel, and it was completed under his leadership in January 1971 . The first commercial sale of the fully operational 4004 occurred in March 1971 to Busicom Corp. of Japan for which it was originally designed and built as a custom chip . In mid-November of the same year, with the prophetic ad "Announcing a new era in integrated electronics", the 4004 was made commercially available to the general market . The 4004 was the first commercially available monolithic CPU, fully integrated in one small chip . Such a feat of integration was made possible by the use of the then - new silicon gate technology for integrated circuits, originally developed by Faggin (with Tom Klein) at Fairchild Semiconductor in 1968, which allowed twice the number of random - logic transistors and an increase in speed by a factor of five compared to the incumbent MOS aluminum gate technology . Faggin also invented the bootstrap load with silicon gate and the "buried contact", improving speed and circuit density compared with aluminum gate . </P> <P> The 4004 microprocessor, the 4001 ROM, 4002 RAM, and 4003 Shift Register constituted the 4 chips in the Intel MCS - 4 chip - set . With these components, small computers with varying amounts of memory and I / O facilities can be built . </P>

Who introduced the first microprocessor for intel in 1971