From the Applications/Games forum:

next dosbox version will allow using hdd images -> using your own system. So files=xx should work. You can alrady check how it works in unsupported CVS version of dosbox.

Can someone please explain how I can use this feature in the CVS version? Like many others, I am trying to use 'files=xx' but it isn't clear from the CVS documentation how this is supposed to work.

Thanks!