DF - DIFFERENCE DISPLAY FOR PRINTABLE FILES - Version 1.1 2/24/80
     by Richard Greenlaw, 251 Colony Ct., Gahanna, Ohio 43230

This program compares two text files and displays the differences. 

Finding the end of a difference between the files requires some 
arbitrary rules since we don't want to generate a series of small 
difference reports just because the old and new text have a few words 
in common.

To avoid this problem, comparisons are on a "line" basis and the user 
can specify the line delimiter character and how many lines must match 
to end a difference.  The end of file mark is also a line delimiter, 
but is not considered part of the line.  The null character is used as 
an end of buffer mark and is converted to endfile if read from a file.

Note that the last line in a buffer may be incomplete but will be 
treated as complete.

Since linefeeds and the delimiter are converted by the output routine 
to CR-LF pairs, to avoid multiple linefeeds or carriage returns, the 
user may specify one character code to be deleted from all file input.

The CP/M command line has the format:

	DF filea fileb options

where filea and fileb may include drives as in b:myname.doc and where 
options consist of key letters followed immediately by a decimal 
number.

Valid options are:
     D decimal value of delimiter character
     M number of lines which must match to end an area of difference
     I decimal value of character code to be deleted on iniut.
Defaults are linefeed, 2, carriage return.

Example:  DF A:XY.C B:XY.BAK M3 I10 D13

Ambiguous file names are not allowed.

Although normal, small areas of difference are processed quickly,
large differences can take several minutes to analyze. Be patient.

The program can be run without arguments for help.