This version of DFU uses Screen Management (SMG) routines to
 perform output. DFU will automatically select SMG unless
 the terminal does not have SMG capabilities, if DFU is executed in
 a batch job or if the logical DFU$NOSMG is defined.
 In any of these 3 cases DFU will switch to normal line oriented
 output.

1  –  Line Mode

 DFU can be forced to line mode output by defining the logical
 DFU$NOSMG to any value.

2  –  Special Keys

 In SMG mode the following keys perform special functions (Keys between
 () are keys on a PC keyboard) :

 o CTRL/W                : Redraws the screen
 o HELP or PF2 (/)       : Invokes the help facility
 o PF4         (-)       : Dumps the screen contents to file DFU_SCREEN.TXT
 o PREV_SCREEN (PageUp)  : Scrolls the output window back (one screen)
 o NEXT_SCREEN (PageDown): Scrolls the output window forward (one screen)
 o INSERTHERE  (Insert)  : Scrolls the output window back (one line)
 o REMOVE      (Delete)  : Scrolls the output window forward (one line)
 o SELECT      (End)     : Toggle between 80/132 columns
 o UP/DOWN               : Recall command buffer

3  –  Paging-output

 In SMG mode the /PAGE qualifier will present output page by page.
 This may be handy for some commands which produce a large
 amount of output (SEARCH, REPORT).