A Microprocessor Controller for Phasing the Accelerator

A microprocessor controller is being developed to perform automatic phasing of the SLAC accelerator. It will replace the existing relay/analog boxes which are ten years old. The new system is all solid state except for the stepping motors that drive the phase shifters. The paper describes the components of the system, the control algorithm, microprocessor hardware and software design and development, and interaction with SLAC's computer control system.