The Machinery Interactive Display and Analysis System (GR-MIDAS™)★ developed by Radian Corporation and GenRad Corporation, acquires and displays dynamic test data for vibration and acoustic analysis of rotating equipment and structures. Using user-defined parameters, the system acquires and displays data in formats defined by the user to be most useful for analysis. The system can be used at test sites, or recorded data can be processed at a laboratory or central engineering facility. The system is composed of a popular minicomputer linked to data acquisition hardware via a parallel interface. Custom software performs data acquisition control, data storage, interactive display, and batch mode plotting. The system has been used to analyze noise and vibration problems in the electric utility, chemical processing, paper, and automotive industries. This paper describes the history and development of the GR-MIDAS system. The system, as illustrated in the examples, has proven efficient and economical in acquiring and displaying large quantities of test data.