18.14 Terminal doesn't scroll
One reason may be that something is wrong with terminfo. Another reason could be that you are outside the scrolling region set for the terminal. Some stupid programs just assume that your terminal has 24 lines and set the scrolling region for 24 lines (by an escape sequence sent to the terminal) without consulting terminfo to see how many lines there actually are. Then when you use another program it may leave the cursor on line 25 where it becomes trapped and the terminal will not scroll. To avoid this problem, create an environment variable "export LINES=25" and also "stty -F /dev/ttySx rows 25". Then the programs that assume 24 lines will hopefully use 25 lines set the scrolling region accordingly.