Connecting an UPS

Recently i found an UPS sitting off to the side of one of the servers, not connected because apparently it had been repaired and never connected back again. Without knowing what make or model of UPS, is it possible to find a way to connect the RS-232 connection to the system using a generic control system?
The OS(es) most likely to run it is (in order of preference): SunOS 5.5, NT Terminal 4.0, Redhat 6.1, Win98