A COMPUTER DISPLAY SYSTEM

Abstract

Computer-driven cathode-ray tube displays are becoming an important means of on-line man-machine communication and have found many applications. In the Project on Cartographic Automation being developed at the University of Saskatchewan it is proposed to use interactive display systems for making decisions. This thesis deals with the assessment of one possible display system. The commercially available Tektronix 611 storage display avoided the "refresh" requirement of standard CRT displays and provided high resolution flicker-free images. The advantages and limitations of a light pen and a "Write-Through Pointer" (a facility to point at a location without storing the beam) were investigated in conjunction with the Tektronix 611 to enable it to communicate with the PDP-8 computer. A light pen was designed, tested and constructed. A part of the logic controls for the storage display was shared with the feedback control in the case of the "Write-Through Pointer". Test programs were written to display cartographic information.