When compiling for DOS, OS/2, or Windows, define MSDOS before you compile.
If you want the ``old style'' of comments, define OLD_COMMENTS. This will
change the comment format so that a c
at the beginning of a line starts
a comment and input on a line is ignored
after a 
is encountered.
This comment format was only used for a early unreleased version of the code,
so you should be able to ignore this. I've kept it in the code for reverse
compatablilty.
The code dcomment_convert.cpp
will convert comments from the pre-1.10 to 1.10 version formats.