When you want to change or erase something you've typed in response to a
"prompt," you use the same keystrokes used to change or erase something on a
"command line." For instance, to erase one character to the left of the
"cursor," you use the DEL key.  To erase the entire line to the left of the
cursor, use the commercial-at sign (@).

     Inserting and erasing characters in the middle of the line requires that
you move the cursor with keystrokes that involve either the CONTROL key or the
ESCAPE key.  To move the cursor back one letter at a time, you press the
CONTROL key and hold it down while typing the letter b.  To go back one word
at a time, you press the ESCAPE key, then release it and type the letter b.
To move forward, you use the CONTROL and ESCAPE keys with the letter f.  If
you want to go to the beginning of the line, use the CONTROL key with the
letter a, and to go to the end of the line, use the CONTROL key with the
letter e.

     Those are the most useful keystrokes, though there are others you might
find handy.  Check the Emacs Text Editor Users' Guide (Order No. CH27).

     There is one other keystroke that comes in handy for big mistakes, such
as when you type a carriage return to conclude your response to a prompt and
then discover that you made a mistake.  You can get the mistakenly typed line
back by typing the CONTROL key with a the letter y.  That will redisplay the
line, and you can then correct it, rather than type the whole line again.

     When you are not using the Multics video system, you can erase only one
character at a time or the entire line.

     To erase one character at a time, type the number sign (#).  That will
erase the character to its left or, if there is blank space immediately to its
left, it will erase all that space back to the next character.  To erase the
entire line to the left, type the commercial-at sign (@).  Notice whether the
symbols appear on your screen or actually erase what's there.  If the former,
that means the video system is not on, and thus you can only erase characters
with the number sign and commercial-at sign.  If the latter, then the video
system is on, so you can use all of the keystrokes discussed above.
     
     You can experiment with this now if you want to by pressing function key
F2.  That will put you at "command level" where you can type command lines and
erase them.


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Historical Background

This edition of the Multics software materials and documentation is provided and donated
to Massachusetts Institute of Technology by Group BULL including BULL HN Information Systems Inc. 
as a contribution to computer science knowledge.  
This donation is made also to give evidence of the common contributions of Massachusetts Institute of Technology,
Bell Laboratories, General Electric, Honeywell Information Systems Inc., Honeywell BULL Inc., Groupe BULL
and BULL HN Information Systems Inc. to the development of this operating system. 
Multics development was initiated by Massachusetts Institute of Technology Project MAC (1963-1970),
renamed the MIT Laboratory for Computer Science and Artificial Intelligence in the mid 1970s, under the leadership
of Professor Fernando Jose Corbato. Users consider that Multics provided the best software architecture 
for managing computer hardware properly and for executing programs. Many subsequent operating systems 
incorporated Multics principles.
Multics was distributed in 1975 to 2000 by Group Bull in Europe , and in the U.S. by Bull HN Information Systems Inc., 
as successor in interest by change in name only to Honeywell Bull Inc. and Honeywell Information Systems Inc. .

                                          -----------------------------------------------------------

Permission to use, copy, modify, and distribute these programs and their documentation for any purpose and without
fee is hereby granted,provided that the below copyright notice and historical background appear in all copies
and that both the copyright notice and historical background and this permission notice appear in supporting
documentation, and that the names of MIT, HIS, BULL or BULL HN not be used in advertising or publicity pertaining
to distribution of the programs without specific prior written permission.
    Copyright 1972 by Massachusetts Institute of Technology and Honeywell Information Systems Inc.
    Copyright 2006 by BULL HN Information Systems Inc.
    Copyright 2006 by Bull SAS
    All Rights Reserved