An operating system comprises instructions for selectively providing an energy-conserving operating state to render an information-processing apparatus operative without relying on a fully-powered host microprocessor. In contrast, the conventional practice has always been making a microprocessor more power-hungry and an operating system more sophisticated for the purpose of remaining operative only if the power-hungry microprocessor is fully powered or for becoming completely inoperative once entering the sleep, standby or shutdown mode. Thus, for the first time, the energy-conserving operating state will render the information-processing apparatus operative at a much reduced speed or power level to cope realistically with the fact that a host microprocessor is often utilized partially or even idled because of being mostly in a state of waiting for receiving the input of data from a keyboard having a highest preset speed of 30 Hz or from the Internet requiring little computation power during file downloading.