if ord (ch) = 200 then % up
        speedy := 1
        speedx := 0
    elsif ord (ch) = 203 then % left
        speedy := 0
        speedx := -1
    elsif ord (ch) = 208 then % down
        speedy := -1
        speedx := 0
    elsif ord (ch) = 205 then % right
        speedy := 0
        speedx := 1
    end if