Problem with NROFF '.cu' command

[Jaap Akkerhuis]

   .... '.cu' command.  Essentially NROFF turns on normal underlining and
   at the same time translates input spaces to underscores.  Unfortunately
   underscores do not break a word, so every word on a line of input text
   is glued together into a single massive word and spaces appear where
   there were input line breaks.  The result ....

No, your are wrong with this. The underlining will be done after all
processing, like adjusting etc. has be done.
Look in n10.c for the details.

The .cu request has always worked in 4.?BSD n/troff, is is nearly the same
as the V7 version.

Since you don't tell what is going wrong, I'm afraid nobody can help you.

Jaap Akkerhuis ...!mcvax!jaap.