Good and Bad Graphics Handling in VT Terminal
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