Also set it to correct three-part value.
/^#undef HAVE_FTIME *$/s/undef/define/
s/^#define USER_FULL_NAME .*$/#define USER_FULL_NAME (getenv ("NAME"))/
s/^#undef STACK_DIRECTION *$/#define STACK_DIRECTION -1/
-s/^#undef CONFIGURATION *$/#define CONFIGURATION "msdos"/
+s/^#undef EMACS_CONFIGURATION *$/#define EMACS_CONFIGURATION "i386-unknown-msdos"/
s!^#undef config_opsysfile *$!#define config_opsysfile "s/msdos.h"!
s!^#undef config_machfile *$!#define config_machfile "m/dos386.h"!