> > > Hi,
> > >
> > > is ClearMamePro able to create diff files for CHDs?
> > >
> > > I'm actually not sure, if this feature is used by Mame at all, but there is
> a
> > > diff folder in the Mame tree, which is market for hard disc difference
> files.
> > >
> > > I understand that this feature would allow me to keep smaller diff files for
> > > rather simliar chds (like clones of roms?) instead of two large, and similar
> > > chds.
> >
> >
> > There is no such support.
> >
> > Roman Scherzer
> > ClrMamePro
> >
>
> Hi Roman,
>
> thanks for the quick reply.
> Is that feature not in ClrMame or not in Mame (or both) ?
>
> ;-)
>
> Cheers,
>
> Emacs
>
> Very funny Scotty...
> now beam down my clothes !!
>


MAME doesn't support that kind of diff-feature. Yes, the diff-files are used to list all differences of two chd files, but MAME is only able to use the diff-file information to apply write-operations to the chd. There is no support to load game A, load diff-file, merge them at runtime to play game B.
Currently diff-files are only used to:
a) apply patches to existing chd files. (to that with chdman)
b) emulate write-operations to chdfiles. The changes are kept in a diff-file and are merged at runtime.

Roman Scherzer
ClrMamePro