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μCOM-42 - NEC
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NEC μCOM-42 Family
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Developer NEC
Manufacturer NEC
Type Microcontrollers
Production February, 1977
Architecture 4-bit word, 10-bit instructions
Word size 4 bit
0.5 octets
1 nibbles
Technology pMOS
Clock 100 kHz-200 kHz
Package DIP42

The μCOM-42 (or uCOM-42) was family of 4-bit microcontrollers, part of the μCOM-4 extended family, specifically marketed for electronic cash registers (ECRs), Point of Sale (POS), and electronic scale applications. These chips were specifically designed for controlling 8x4 keyboards, 8-digit displays, and various ECR-type printers. The μCOM-42 had a separate, modified instruction set, compared with the rest of the μCOM-4 families.


μCOM-42 Microcontrollers
μCOM-42μPD54819771920x10 bit96x4 bit42
μCOM-42 EVACHIPμPD555197796x4 bit64


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μCOM-42 Instruction Set[edit]

Main article: μCOM-42 ISA

The μCOM-42 ISA had a set of 72 instructions. Every instruction is a single 10-bit word

See Also[edit]

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Facts about "μCOM-42 - NEC"
designerNEC +
full page namenec/μcom-42 +
instance ofmicrocontroller family +
instruction set architectureμCOM-42 +
main designerNEC +
manufacturerNEC +
nameNEC μCOM-42 Family +
packageDIP42 +
technologypMOS +
word size4 bit (0.5 octets, 1 nibbles) +