μCOM-4 is a microcontroller (microprocessor) family introduced by NEC in 1973. It had a 4-bit architecture. The microcontroller ran at 1 MHz clock speed and had 4Kb of address space. It was manufactured as Sharp requested them for their products. The first chip in the family was the μPD751, a single-chip microprocessor.
NEC released the μPD707 and μPD708, a two-chip 4-bit CPU, in 1971. They were followed by NEC's first single-chip microprocessor, the μPD700, in April 1972. It was a prototype for the μPD751, released in April 1973, combining the μPD707 and μPD708 into a single microprocessor.
- ↑ 1.0 1.1 NEC 751 (uCOM-4). The Antique Chip Collector's Page. Archived from the original on 2011-05-25. Retrieved on 2010-06-11.
- ↑ 2.0 2.1 1970年代 マイコンの開発と発展 ～集積回路, Semiconductor History Museum of Japan
- ↑ Jeffrey A. Hart & Sangbae Kim (2001), The Defense of Intellectual Property Rights in the Global Information Order, International Studies Association, Chicago