(UPS) A bATtery powered power supply thAT is guaranteed to provide power to a computer in the event of interruptions in the incoming electrical power. Different rATing UPSs will provide power for different lengths of time. Modern UPSs connect to the computer' s serial port and provide informATion such as bATtery time remaining, allowing the computer to shut down gracefully before complete loss of power. (1996-12-11)