There is a class of terminals where different video attributes cannot be supported in a general manner. For this class of terminals, the code that changes the video attribute of the terminal occupies a space on the screen. For this reason, it is almost impossible to write a general windowing package that will support different video attributes on this class of terminal. The TeleVideo 910, 914, 924, 925, Qume QVT-101, QVT-102 and Esprit Systems Esprit III are some of the terminals that exhibit this behavior.
For the terminals that display the attribute-change code on the screen, all video attributes other than NORMAL are automatically mapped to NORMAL. This allows code written for more "standard" terminals to run on this class of terminals without modification.
