    
    
               Hit uppercase letter of following options:

Help       : displays this screen
Modif.     : redefinition of graphic type
Pres.      : various presentation options (graduations, margins, etc.)
Eye        : eye diagram, or not
Zoom       : expands abscissas axis by two
Ret.       : contracts abscissas axis by two
reTrace    : initial graphic, editions out of frame being maintained
Quit       : program continuation
PRTSCR     : (PrtScrn key) prints graphic, if ad hoc TSR loaded
F2         : cursor visible or not
F10        : normal mode (the last one) 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 graphic window, or not.

F4 : reduces graphic 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 : abandons graphic drawing, and goes to the "Graphics" module menu.
     Saves time if N is high and graphic no more needed.

F6 : (toggle), in C coordinates only, increases the size of constellation
     points.
     For graphics drawn within a particuliar module (Module BER, Diff.gain,
     etc.), F6 displays either a line joining the computed points, or only
     these points.

