SCROLL [UP  ] [ BY scrl-num {LINE } ]
       [DOWN]               {LINES}
  1. The SCROLL phrase specifies the number of lines to scroll the current window. Scrolling is the first operation performed by the ACCEPT or DISPLAY statement--it occurs before any cursor positioning or the operation of any ERASE clauses. Scrolling does not affect the current cursor position.
  2. If the UP phrase is specified, the contents of the current window are scrolled upward (normal scrolling). If DOWN is used, then the contents are moved downward (reverse scrolling). A blank line with the default video attributes for the window is introduced at the top or bottom of the window (as appropriate). Upward scrolling is used if neither the UP nor DOWN phrase is specified.
  3. If a scrolling value is specified, its value is the number of lines to scroll the screen. If this value is not positive, no scrolling occurs. If the scrolling value is omitted, one line is scrolled.