Trimming old diffs to save space

[Ed Avis]

I have some huge files under version control.  It is unlikely I'll
want to roll back to earlier revisions, although I'd like to keep the
log messages.  What I want to do is remove the diffs from the RCS
file so that the current revision is available but older ones are
lost.  This is, of course, to save disk space.

Is there a tool I can use to do this?  Or should I write a quick Perl
script to do it?  Not knowing much about the internals of the file
format, is there anything I should look out for?

The files are in fact managed by CVS but since my question is about
low-level manipulations on the RCS file format I thought this list
would be the best place to ask.  Please cc replies to me.

-- 
Ed Avis <address@hidden>