Use the statement writeln('<14>'); to clear the screen.
PROGRAM NINE Table of 1 to 20 Celcius program PROG9 (output); var farenhiet : real; celcius : integer; begin writeln('<14>'); {clear screen on DG machine} writeln('Degree''s Celcius Degree''s Farenhiet'); for celcius := 1 to 20 do begin farenhiet := ( 9 / 5 ) * celcius + 32; writeln( celcius:8, ' ', farenhiet:16:2 ) end end.