Intel 4004 CPU

USA, 1970

Intel had a prototype of this central processor since 1969 and the costs of development were already paid for. Now Intel had to make a choice: either they shelved the project or the chip could be used as model for a chip that Intel could make and pay for by them selves. Thus the Intel chip became the first micro processor⁽¹⁾. The invention is published on 15 November this year in Electronic News⁽²⁾

So the first single chip CPU was the Intel 4004. It processed data in 4 bits, but its instructions were 8 bits long. Program and data memory were separate, 1K of data memory and a 4K of program memory (in the form of a 4 level stack, used for CALL and RET instructions). There were also sixteen 4-bit general purpose registers(3) The processor' speed is 60.000 operations per second.

Specifications

The 4004 consists of 2,300 transistors based on 10 micron technology fitting on a 12mm² area.

The microprocessor has 46 instructions. The 4040 is an enhanced version of the 4004, adding 14 instructions, larger stack (8 levels) and 8K program space. It can address 640 bytes. Documentation is written by Adam Osborne. The chip is introduced to the public in Las Vegas by Wayne Pickette. The sales price will be US$ 200 per piece.(5)