The implementation of a common user interface design across a heterogeneous host/display device environment

The design, architecture, and implementation of the Pacific Bell Virtual Workstation (pbVWS) are described. The objective of this project was to provide a working subsystem which would: define and enforce a companywide policy for user interaction with Pacific Bell applications; enhance end-user and programmer productivity; support the existing user-display-device base yet allow easy migration to newer equipment over the next 3-5 years; and provide usability equal to or better than is now available for a given class of display device. The device-side protocol handler takes care of the details (and some of the semantic interpretation) of the commands to control the actual device whether it is a single-function terminal (e.g. VT100, 3270) or an actual workstation. The pbVWS software implements such a handler for this range of devices