a .dms is a disk masher disk image. the file from aminet is the package that contains dms.
dms is the program for writing it back. Run it from shell.. If you cant work out how to do that, there is a gui for dms on aminet too.
Its been over 10 years since i used dms, but it ran from shell/cli,
dms write crap.dms to df0:
or summat along them lines.
