COMMENT ⊗   VALID 00002 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002		CODE:	Encode and decode files.
C00005 ENDMK
C⊗;
	CODE:	Encode and decode files.

			R. E. Gorin
			8 August 1971


	CODE is a program to encode disk files and decode files  that
have  been  encoded.   Protection  of the file contents is secured by
means of an encoding key, which is invented  by  the  user  for  each
file.


	Operating instructions.

	To start CODE, use the command: R CODE.

	Code will request the name of the input file, the name of the
output file and a keyword.

	The  file  names  should  be  typed  using  the  usual system
conventions.

	The keyword  is  very  important.   The  keyword  guards  the
encoded  file.  Without  knowledge  of  the keyword it is essentially
impossible to recover the encoded file.  The  keyword  has  arbitrary
length;  it  is terminated by a carriage return.  The key can contain
only characters from the 64 character set, which includes  the  upper
case  letters,  the digits and certain punctuation.  For convenience,
any lower case letters that are typed are converted to upper case and
invalid characters are deleted.  The keyword that is actually used by
the program is typed as verification.

	After these three  things  have  been  specified,  CODE  will
encode the input file and write the result on the output file.

	To decode a file, the exact same process is used. The encoded
file is named as the input file and the output file will receive  the
clear  text.   It  is  necessary  to  specify  the  same keyword when
decoding as was specified on encoding.