GNU Emacs Manual
AD.9.3 Garbage on the Screen
If the data on the screen looks wrong, the first thing to do is see
whether the text is really wrong. Type C-l to redisplay the
entire screen. If the screen appears correct after this, the problem
was entirely in the previous screen update. (Otherwise, see the following
Display updating problems often result from an incorrect termcap entry
for the terminal you are using. The file `etc/TERMS' in the Emacs
distribution gives the fixes for known problems of this sort.
`INSTALL' contains general advice for these problems in one of its
sections. Very likely there is simply insufficient padding for certain
display operations. To investigate the possibility that you have this sort
of problem, try Emacs on another terminal made by a different manufacturer.
If problems happen frequently on one kind of terminal but not another kind,
it is likely to be a bad termcap entry, though it could also be due to a
bug in Emacs that appears for terminals that have or that lack specific