The Control Mode routine controls the mode of the pasteboard.
    This includes buffering, minimal updating, whether the screen
    is cleared when the pasteboard is deleted, and whether tab
    characters are used for screen formatting.

    Format

      SMG$CONTROL_MODE  pasteboard-id [,new-mode] [,old-mode]

                        [,buffer-size]

  Additional Information (explode) :

• Returns
• Arguments