Abstract: A computer system having a removable component, such as a removable hard disk drive, and an electromechanical switch that mechanically locks and releases the component. The switch also generates an electrical signal when the component is released. At this point, before the component is physically removed, the central processing unit ("CPU") of the computer executes software that causes the computer system to save what information is necessary for recovery and suspend the system. When the system resumes, the CPU determines whether the component was replaced and, if so, causes an appropriate message to be displayed. The user then may select whether to reset the system or to resume.

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.