    
    
               Hit uppercase letter of following options:

Help       : displays this screen
Modif.     : redefinition of graph type
Pres.      : various presentation options (graduations, margins, etc.)
Eye        : eye diagram, or not
Zoom       : expands abscissas axis by a ratio 2
Ret.       : contracts abscissas axis by a ratio 2
reTrace    : initial graph, editions out of frame being maintained
Quit       : program continuation
PRTSCR     : (PrtScrn key) prints graph, if an ad hoc TSR is loaded
F2         : cursor visible or not
F10        : (toggle) normal mode or edition mode.
             In edition mode, you may add a title, comments, redefine
             coordinate axis, etc.
             To do so, move the cursor, edit (letters, numbers, etc.),
             erase with SPACE or BACKSPACE keys.
             Help erases all editions.

Other controls:
--------------
F3 : (toggle) displays a frame around the graphic window, or not.

F4 : reduces graph height by a ratio 1 + X
     Every first 5 hits of F4 increment X by 0.1
     The sixth nulls X, etc.
     Useful to display the higher part of some templates.
F5 : - stops graph drawing, and goes to "Graphics" module menu (saves time
       if N is high and graph no more needed).
     - after the graph is drawn, and only in case of filter display, F5
       toggles between phase and group delay.
F6 : (toggle), in C coordinates only, increases the size of constellation
     points.
     For graphs drawn within a particuliar module (Module BER, Diff.gain,
     etc.), F6 displays either a line joining the computed points, or only
     these points.
F7 : allow to modify colours. As soon as module "Graphics" is quitted,
     colours take again their nominal values.
