A twelve-month program has been conducted to develop an optical diagnostic device for measuring the quality and jitter of a high energy laser beam. The beam diagnostic device developed consists of two sets of variable frequency, electromechanical scanners mounted in an orthogonal configuration, such that scans can be taken of a focused beam in both X and Y directions. The scanning system, its tracking of the beam centroid, data acquisition, and beam quality and beam jitter calculations are controlled by a PDP/8e minicomputer. A fully computer-controlled system has been found to be essential, since a large quantity of data is required for determination of beam quality and beam jitter/wander. The breadboard device was fabricated and assembled and underwent preliminary testing and checkout in the laboratory using a HeNe laser. Following this, the device was moved to the Capistrano Test Site for design verification testinf using a chemical laser. A hot firing was conducted on 6 June 1975 with the diagnostic device operating under full computer control. All expected data were obtained.