Interfacing and software for CRT displays

The author discusses the functionality of modern display controllers used in real time control room applications such as motorway control centre, nuclear power stations and air traffic control. The actual visual display unit (VDU) is a super television screen where the picture is built up of a matrix of dots (pixels) traversed by a raster. The real time system features double buffering of the pixel memory and a display list memory in the display controller. The display list can be edited as the real world changes and periodically call for a new picture to be generated in the second pixel memory to change only when the new picture is complete. Software graphics packages such as GKS, are briefly discussed