Use of a simple storage ring simulation for development of enhanced orbit correction software

At the Advanced Photon Source (APS) most of the testing of minor operational software is done during accelerator studies time. For major software changes, such as the porting of the complex workstation-based orhit control software to an EPICS IOC, much of the testing was done 'offline' on a test IOC. A configurable storage ring simulator was created in a workstation with corresponding control system records for correctors and orhit readbacks. The simulator,s features will he described as well as the method used to develop and debug the most recent improvement of the APS orhit control software, among others. The simulator is also useful in general-purpose software testing.