The parameters of roll/scroll functions should refer to the data being inspected, not to the window.
Additional Information:
From a data orientation, "roll up 5 lines" means that the top five lines of data would disappear and five new lines would appear at the bottom; the window through which the data is viewed remains fixed. However, when a windowing orientation is established, the wording of scroll functions refers to the display page (or window) and not to the displayed data. In that case, the command "Up 10" would mean that ten lines of data will disappear from the bottom of the display and ten earlier lines will appear at the top.