Andy McFadden <fadden@fadden.com> wrote:
DDD created files with that sort of name; the number is the length in
sectors. If so, they should open with CiderPress.
Forgot to mention: double-clicking on the file will just open it in the
file viewer, so you need to right-click on the file and select "Open
as disk image".
Doing the actual conversion is a little more round-about: there's no direct
way to convert a disk image stored on a disk image to something else. You
have to extract the file in "preserve Apple II" mode, and open it directly
with CiderPress. (If you rename it to "foo.ddd" it'll show up in the file
selection dialog.)