Good and Bad Graphics Handling in VT Terminal Emulators

The following images are examples of correct and incorrect graphics handling in terminal emulators. The images on top of each pair represent correctly handled graphics in several common VT graphics situations. On the the bottom image of each pair, the same graphics handled by a terminal emulator that handles graphics controls inadequately.

The first comparison is of a welcome message display with fancy graphics including double size letters and highlighting. The screen below handles all graphics in the welcome message and renders them readable. The blue screen below that with incorrectly handled graphics controls is readable but doesn't render the graphics correctly.

Using EVE editor to open a large text file with columns of numbers shows that the inadequate graphics control of the blue terminal display, below, shows that it can not display the beginning of the file and for some reason puts one of the lines below the status display.

The next screen correctly handles the display of the EDT editor keypad help display while the blue screen following chops the top line of the display.

Finally, exiting from the editor om the first screen ,below, correctly displaces the display of the edit file upward and concludes with a "$" prompt. The screen following can not remove the display and ends up with a "$" prompt followed by one of the lines of the file that was being edited.