On November 15, 1971, the chip was mentioned for the first time publicly in a half-page ad printed in Electronic News. Intel was just two years old back then and it was first to offer a CPU that was integrated entirely in one package.

The 4004 initially went against the idea of Intel co-founder Robert Noyce, who believed that selling an integrated chip as opposed to multiple chips would be a silly move from an economic view. The original effort to develop an integrated processor at Intel can be traced back to NASA engineer Austin Roche, who proposed the idea of developing a CPU to Intel during a meeting with Noyce in 1968. Noyce, in the end, gave $50,000 to Roche to develop the chip. A contract signed with Busicom in 1969 to develop 12 separate semiconductors for a programmable calculator laid the foundation for the 4004: Intel determined that only an integrated chip could meet the cost requirements of the product.

The 4004 was built with a total of 2300 transistors in a 10,000 nm process and was capable of running about 92,600 instructions per second. The first processor were clocked at 108 KHz, which was increased to 740 KHz in the production products, which were shipped to the first customer, Busicom, in February in 1971. However, Intel considers the ad in Electronic News as the real birthday of the CPU. As part of its contract with Busicom, Intel delivered three more support chips - the 4001 ROM, the 4002 RAM and the 4003 static shift register. Busicom, which owned the rights to the 4004 design through the contract with Intel, reportedly sold about 100,000 141-PF calculators with Intel's chips. Intel repurchased the rights to the 4004 design for $60,000.

According to Intel, current 32 nm CPUs are about 5000 times faster than the original 4004 and each transistor uses about 5000 times less energy, while the price of each transistor dropped by about 50,000 times.

That's progress.