Thanks, folks, for these first insights and sorry for the lack of further information. Equill -- the files are all .img. Some have the familiar Disk Copy image icons (and FileBuddy identifies them with a "dImg" type and "ddsk" creator), some have blank icons and the type/creator is wrongly identified with a GraphicConverter image format.

I didn't think about ShrinkWrap -- I'll look for it in my archives -- thank you, TylerEss.

I also didn't imagine that StuffIt could handle disk images... I was so accustomed to using it always to decompress .sitted or .zipped archives. Anyway, I just tried with StuffIt Expander 5.5 but nothing happens: when I drag the .img file over StuffIt Expander, the application opens and closes without doing anything.

I'll look for ShrinkWrap and keep you posted. Thanks all, for now.

Cheers

Rick