Abstract: A portable microcomputer has a battery for powering the microcomputer. A display has a light source for illuminating the display. A system of illuminated indicators for indicating various operating states or functions of the microcomputer comprises a plurality of passive illuminated indicators, each deriving its visual signaling energy solely from the light source, and at least one active illuminated indicator indicating a condition related to the electrical power for the microcomputer and electrically powered by the battery. The passive indicators are effective, with no drain on the battery, except to change the state of an associated shutter, to provide necessary or desirable indications of various operating states or functions of the microcomputer when the microcomputer is being used and the display is active, only the active indicator draining the battery to provide said indication of electrical power.