Use of a raster framebuffer in vision research

For the study of human and animal vision, the video framebuffer is the only technology that is capable of displaying two-dimensional images with precise control of contrast, luminance, and display timing. The video framebuffer also allows precise control of color. However, this device is not designed for precise psychophysical displays, and techniques must be developed to use them in this role. In this paper, we describe a number of basic methods used in our lab. In order to be concrete, we use an Adage RDS-3000 raster display system (Adage, 1982) as an example, since that is the device we have actually used. The Adage is hosted by a PDP-11/73 under the Venix operating system. The principles generalize to other machines. Where it clarifies the issues, we have shown the syntax of the software routines involved.