The NEC μCOM series is a series of microprocessors and microcontrollers manufactured by NEC in the 1970s and 1980s. The initial entries in the series were custom-designed 4 and 16-bit designs, but later models in the series were mostly based on the Intel 8080 and Zilog Z80 8-bit designs, and later, the Intel 8086 16-bit design. Most of the line was replaced in 1984 by the NEC V20, an Intel 8088 clone. Overview The μCOM series has its roots in one of the world's earliest microprocessor chipsets, the two-chip processor µPD707 / µPD708. Early in 1970, Coca Cola Japan set out to increase the efficiency of their sales outlets by introducing new POS terminals. Sharp was contracted to build these terminals, and NEC in turn to develop a chipset. The chipset development was complete in December 1971, at about the same time as other early microprocessors in the USA. Since then, NEC has developed and manufactured various microprocessors and microcontrollers. General-purpose products among them were given series names starting with μCOM. The μCOM-4 series (4 bit) and μCOM-16 series (16 bit) were original developments, while the μCOM-8 series (8 bit and 16 bit) consisted mostly of Intel- and Zilog-compatible microprocessors. The μCOM name disappeared when the V series and 78K series appeared in the 1980s, and the μCOM-87AD series, for example, came to be described simply as the 87AD series. μCOM-4 series μCOM-4 The μCOM-4 (μPD751) is NEC's original single-chip 4-bit microprocessor, announced in 1973. Unlike the Intel 4040, the μPD751 has separate data and address buses. A number of peripheral integrated circuits were provided for the μPD751: μPD752 - 8-bit I/O port μPD757 - Keyboard and display controller μPD758 - Printer controller μCOM-41 The μCOM-41 (μPD541) is a PMOS microprocessor in a 42-pin package. The following peripheral integrated circuits were available: μPD542 - ROM plus RAM μPD543 - ROM plus I/O port μCOM-42 The μCOM-42 (μPD548) is a 4-bit PMOS microcontroller in a 42-pin package. It has built-in ROM (1920 × 10 bit) and RAM (96 × 4 bit) as well as keyboard, display, and printer controllers. The μPD548 requires a power supply of -10V and the outputs can switch up to -35V. A ROM-less chip (μPD555) in a 64-pin quad-in-line package was available for hardware and software development. μCOM-43 through μCOM-46 The μCOM-43 series consists of more than 10 different 4-bit microcontrollers. Broadly speaking, there are PMOS devices