Format 4

DISPLAY SCREEN SIZE shifts the display between 80 and 132 column mode


   [ ON EXCEPTION statement-1 ]

   [ NOT ON EXCEPTION statement-2 ]


Syntax Rules

  1. Different formats of the DISPLAY statement may be mixed together in one DISPLAY statement, as long as no ambiguity results. The effect is the same as specifying each DISPLAY statement separately.
  2. statement-1 and statement-2 are imperative statements.

General Rules

  1. The DISPLAY SCREEN verb is used to shift between the 80-column mode and 132-column mode of the terminal. On character-based systems, the terminal is physically set to either 132- or 80-column mode. For all systems, the main application window is then set to 132 columns wide; it is cleared, and its subwindow set to cover the entire interior. Some graphical systems simulate 132-column mode by scrolling the main application window.

    In graphical environments, the MODIFY verb is the preferred method for changing the size of a graphical screen.

  2. If the terminal hardware does not support the mode shifted to, the screen and current window do not change and the EXCEPTION phrase statement-1 (if specified) executes. If the mode change is successful and the NOT EXCEPTION phrase is used, statement-2 executes.