The unique measurement requirements of our industry have, in the past, been served by general purpose test instruments requiring a high degree of operator interface and understanding. As technology advances, the microprocessor will smooth this interface and improve operating efficiency. Microprocessors allow us to configure an instrument to handle our unique requirements. Application of the microprocessor in the design of a new simultaneous-sweep system will emphasize the areas of improvement made possible by the use of this versatile component. The use of microprocessor control allows us to get the most useful information for the time spent testing. Areas where the microprocessor has had considerable influence are: minimization of the number and types of controls, digital storage of sweep response, communication between instruments, and post processing of response data. These areas will be discussed in some detail, along with the idea of upward expandability.