4004

4004 refers to Intel’s 4-bit central processing unit released in 1971 as part of the MCS-4 microcomputer system. It is widely regarded as the first commercially available microprocessor, designed to serve as the central control unit in a complete single-chip computer. The 4004’s development emerged from the collaboration between Intel and the Japanese calculator company Busicom; the project was led at Intel by Federico Faggin, with Masatoshi Shima contributing to the architecture and design.

Technically, the 4004 features a 4-bit data path, a 12-bit address space, and a relatively small transistor count of about 2,300. It was packaged in a 16-pin dual in-line package (DIP) and operated with a clocked instruction set designed for use in embedded calculation and control tasks. The architecture relied on an ecosystem of support chips in the MCS-4 family, including 4001 ROM, 4002 RAM, and 4003 I/O/shift register components, enabling developers to implement complete microcomputer systems around the processor.

Impact and legacy: the 4004 marked a turning point in computing by demonstrating that a single integrated circuit could function as a complete processor, paving the way for subsequent generations of microprocessors. It influenced later designs and contributed to the development of embedded systems and early personal and business calculators. While surpassed by more capable 8-, 16-, and 32-bit processors in the following years, the 4004’s successful introduction established a new paradigm in electronics and computer architecture.