Because good research needs good data

Amiga disk data recovery: progress and limitations

Chris Rusbridge | 19 April 2009

You may remember that I have been attempting to recover files and content from various sources from 10 or more years ago. One of these was an Amiga disk. On the label is the note: "Dissertation 17/4/96, CV.asc, CV, 29 September 1996".

I’ve described earlier some attempts to get the Catweasel controller to read the disks. After eventually figuring out how to configure the disk-reading program ImageTool3 for the Catweasel, I tried the Amiga disk. It worked fine, with as far as I can see zero errors. From a cursory scan of Google, I reckon this raw disk format is known as ADF, so I renamed it XXXAmiga.adf (.adf was one of the candidate extension names under the selected "Plain" category for the ImageTool3 program).

Now, of course, we have to work out first how to extract files from the disk image, and then how to convert your particular file format into a modern day format.

Just simply reading the raw disk image with Notepad on Windows or Textedit (on my Mac) shows that there is real text there, that made sense to my colleague (see below)!

A comment from “Euan” on my earlier post suggested that we try the WinUAE Amiga emulator, and my colleague did that. He reported:

“Success. I've not only got the WinUAE Amiga emulator working, but managed to find a copy of the application that I wrote my CV and dissertation in (Final Writer 5) and have been able to read the files off the disk image you sent and display them (screenshots attached).

Not having any luck reading the individual files directly [CR: from his Windows system], though -- other than the odd word related to fonts and colours -- but then they are in native FW5 format.”

Image from the dissertation seen in Final Writer
I asked if he was able to do any "save as" operations in his emulated Final Writer program, to move files from the disk image into the Windows file store. He reported:

“I've tried re-saving my files in another format, if that's what you mean, but the program doesn't do anything -- I can select Save > Save As... from the menu but nothing happens. However, I can see all my individual dissertation files from my PC as the file system is mapped onto a directory.”

Raw image from the same part of the dissertation grabbed from Textedit on the Mac

It was remarkable how much could be read directly in the disk image!

Now my colleague was able to read his CV.asc file with Notepad on Windows, but so far we have not been able to convert the dissertation to a modern format, nor to connect the Final Writer program inside the emulator to a printer. Frustratingly close, but still not quite where we would like to be. I did find a demo copy of Final Writer for Windows 95 on the WayBack machine (earliest lift of the site, also 1996), but unfortunately this wouldn't open the existing image unless we upgrade to the full-featured version... but the company appears to have gone bust in 1996-7 or thereabouts!

So what have we learned from this?

  • It is possible to read a 13 year old floppy disk from an obsolete machine with an apparently incompatible disk format, kept under conditions of less than benign neglect, using cheap hardware on a recent Windows PC.
  • It is possible to access the files from the obsolete operating system using an emulator that appears to have been written by spare time volunteers.
  • It is possible to run the original application that created some of these files, under the emulator, and to read and process them (but not, so far, to save in another format).
  • Using the emulator is valuable, but constraining (in being unfamiliar technology, with few manuals etc) and limiting (in not, so far, being able to do much more with the files). We would now like to migrate them to a modern environment; for my colleague, this means Windows or Linux.

Fascinating!