Logical Input Devices — An Outdated Concept?

This chapter gives a short history of the concept of logical input devices and the way in which the concept has evolved and is now contained in the ISO/IEC standards for computer graphics programming, GKS, GKS-3D and PHIGS. A formal description of the GKS logical input device model is given in Hoare’s CSP notation, and the chapter concludes with a discussion of some of the shortcomings of the model and ways in which it can be extended.