The Intel 4004 was one of the first microprocessors ever produced, released in 1971. The 4004 was designed by Federico Faggin, Masatoshi Shima and others.
During the development of the 4004, few people foresaw the potential of microprocessors as integral components in computers for use by the general public. The 4004, which was part of the MCS-4 family of chips, was developed mainly for use in calculators, cash registers, ATMs and other simple business systems.
The 4004 had a 4-bit processor. The instructions were stored in ROM, while the data was stored in an external register. The 4004 used a 4-bit address bus.
It also produces a maximum clock speed of 740 kHz and could give upto 92600 instructions per second! It had 12-bit addresses with a 8-bit intrusions & a 4-bit words. Intel 4004 also had a separate program and data storage!