Definition
A small, self-contained computer built around a microprocessor as its central processing unit, with integrated memory and input/output circuitry on a single circuit board or within a compact enclosure. Microcomputers form the processing core of most modern avionics, including flight management systems, GPS units, engine monitors, and electronic flight instrument displays.
Plain English
A small computer, built around a single chip, that runs a specific job inside a piece of equipment. In aviation, the boxes behind your panel that drive the displays and instruments are microcomputers.
Context Anchor
Seen in descriptions of electronic aircraft instruments, navigation equipment, engine monitors, autopilots, and maintenance manuals.
Derivation
From Greek mikros, meaning small, combined with computer. The name distinguishes it from the room-sized mainframe and minicomputer systems that came before it. The 'micro' refers to physical size and the use of a microprocessor chip, not to limited capability.
Why Pilots Care
Nearly every modern instrument and avionics box in the cockpit contains one or more microcomputers. Understanding that these units are computers helps explain why they need power-up time, occasional software updates, and why a reset can sometimes clear an unexpected fault.
Intuition Check
A microcomputer is not necessarily a personal computer with a screen and keyboard. In aircraft, it is often a small hidden computer built into a piece of equipment.
Example Sentence 1
The GPS navigator uses a microcomputer to calculate position, track, and groundspeed from satellite signals.
Example Sentence 2
Maintenance crews check the microcomputer outputs during preflight to confirm all sensor readings are within limits.