Numeric
The Vscroll switch controls the number of lines scrolled up or down when you move the cursor out of the window. When the window is smaller than the full screen, the amount scrolled is in proportion to the window size.
The minimum value for Vscroll is 1. Text is never scrolled in increments greater than the size of the window.
The Mlines and Plines functions also scroll according to the value of the Vscroll switch.
Vscroll:1
Hscroll