The cathode‐ray oscilloscope is usually regarded as a means for displaying data in one or two variables as a function of time. By means of simple transformations which are easily performed electrically, it is possible to present three variable electrical data in the form of isometric or other conventional projections or as true perspective drawings. It is further possible to change the observer's viewpoint in the presentation coordinate system at will by turning range, elevation, and azimuth controls. A more elaborate but similar set of transformations permits presentation of separate pictures to the two eyes. These pictures are optically superimposed but differ in such a way as to yield stereoscopically correct perspective pictures. These pictures are fully acceptable to the eye as patterns in space.