The uninterruptible power supply (hereafter referred to as UPS) has become an integral part of modern computer and communication systems. Various topologies have come to the fore in recent times with the advent of high frequency switching techniques. This project considers such a high frequency operated UPS system. It is modeled, and simulated to provide insight and information for design studies. A framework for the software simulation of a class of UPS is proposed in this document and its implementation results are given. The simulation and the user interface software structures and their implementations are also included. It is intended that the software can be modified on a modular basis to enable the simulation of various topologies of UPS that are in vogue and that may emerge in the future.