Uncompress DiskDoubler Files on OS X

If you are an old Mac hand, as, young and vital as I am, I seem to be, you may have odd old files lying around, possibly on floppies.

Assuming you can get them onto your Mac OS X system (floppies? How…1984), you may find they are unreadable. You might even find they are labeled “DD”. Stuffit Expander doesn’t know how to deal with them. However, it turns out you can trust that backwards compatibility on a Mac will actually rival Windows.

Go to ye olde HyperArchive, a site you may dimly recall from the mists of time. Find the line that says:

Abstract of dd-expand-40.sea.hqx 181K (12/20/1993) Download

And click the “Download” link. Yes, the file date is 1993, and yes, that’s a 181K file. That app will browse your filesystem to this day and expand any DiskDoubler archive. This is what we used before hard drives were cheap. It used the LZW compression algorithm, apparently, which is why open source tools don’t decode it. It is now basically abandonware by Symantec. Thanks, Symantec.

But anyway, this file from 12 years ago opens and runs just fine in emulation, and it managed to get a bunch of my old files recovered.


23 thoughts on “Uncompress DiskDoubler Files on OS X

  1. You will have to have classic installed, but I am running 9.2.2, so I don’t think it has to be an early version.

    However, as long as you have classic installed, you don’t have to boot from it, just run the program from within OS X in emulation.


  2. Thank God for this tip, google and the internet. I have had a wealth of 8+ year old files compressed with DiskDoubler that I thought I would never be able to access again. Lots of old graphics and photos that are very imprtant. The Norton Expand didn’t work. I happen upon this little tip, downloaded the DD Expand and now my files are accessable and can be saved THANK YOU, THANK YOU, THANK YOU!!!!


  3. Ditto on the thanks. I only had a few DD files but they were important ones that would have taken a whole lot of work to recreate. Thanks to all who helped keep this site, and to Goggle for making it easy to find.


  4. I used Disk Doubler extensively back in ’93 to avoid filling up the 1 GB LaCie hard drive we purchase for $1,100 for our MacIIci file-server (Boy do I feel old). A coworker recently came to me to retrieve some 12-year-old files from our archives. Was I relieved when I found this link. THANK YOU!


  5. dude,
    thanks so much for posting this info… i about sh__ myself when i saw that a brochure we did 10 years ago was compressed using diskdoubler. you saved me about a weeks worth of work recreating everything.
    thanks again, and i’ve forwarded the site address to a bunch of my friends for future use.


  6. Thank You!!!! I wrote an entire book on Word 4 in the 1980s and was unable to open it. You saved something that was very valuable to me!!!! Thanks!!!!


  7. I’ve been asked to try and recover the contents of two old Mac files, possibly compressed with Disk Doubler.

    One file was a Word document, and the other was a PowerPoint document. Both have been since copied from the Mac to a PC and emailed around, losing the file type/creator information. Neither has an extension.

    Both look like random junk inside (no printable text apparent), but both do have a first line that might yield a clue.

    The former Word document contains “CWDBNMSWD” in its first line.

    The former Powerpoint document contains “SLDSPPNT” in its first line.

    Does anyone know plausable type and creator codes I could try?


  8. Stumbled on you through Google just as I was getting the razor blade out of its sleeve.
    Needed to access some very old DD files and get ’em into Illustrator on System X. Done. Took about 29 seconds. Ya blood’s worth bottlin’. Thanks.


  9. Anybody any idea how to expand Artpro 6 files in OSX that were disk doubled in OS9.

    Any views would be very much appreciated.



  10. Dude, I made my living as a tv writer in the early 90s and made extensive use of DiskDoubler. All my stories and scripts and notes and…everything, were compressed with DiskDoubler. And over the fullness of time these precious files were moved into archives and shuffled across hard disks and I moved on to OSX…and, well, you get the picture. Those old gems of mine were no longer openable. If it hadn’t been for your cool little page and Google I might not have found the DD Expander tool I needed to open those old files! Well, thanks to you and Google I did find the right tool and now all my old DiskDoubled archives have been opened and are available for reading and rewriting again! Thanks so much. You get bigtime good karma points for this!




  11. I second Sandy Smith’s earlier comments:

    “Thank God for this tip, google and the internet.”

    I have multiple 13+ year old files compressed with DiskDoubler that I, too, thought I would never be able to access again.

    Now I have them all available.

    Thanks so much!



  12. hi there!,after a long time atached to my old power mac,he died.
    my new mac runs macos x.4.2.
    i,m having the same problem(iguess?),but after instaling dd expand.sea,a window said:classic doesn´t find any sistem file of mac os 9 in the hard disk.
    it also sugest me to instal macos9.1 ,to suport classic.
    it seams that the only way for me to be able to open DDExpand.sea is by instaling macos9?
    i thougth it was all done,but maybe not.
    thanks a lot


  13. i have images which is save in DiskDoubler as a compressed file onto a CD. How could I extract them on a PC Windows?


  14. Thanks so much! This saved the day!!! Was at my wits end trying to open old dynamic graphics files.


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