A rotator for X/Y oscilloscope displays

A simple and relatively inexpensive electronic circuit is described that will generate the Cartesian coordinates of a rotated display for both the X- and Y-axes of a conventional oscilloscope type of display monitor. The device will rotate the display through fixed angles and possesses the merits of very low intrinsic noise and extremely high speeds of response. It is particularly suited for computer control of stimulus orientation in psychophysical investigations of spatial contrast vision.