The IBM PC Disk dats were started by Grendel long ago i think, he was using his original media (for obvious reasons) to create the IMG files but i don't remember which software and don't have the logs anymore.
Maybe you can try some different tools to see if you can open the images or even recreate some of the dumps if you have some original disks of existent sets i guess. Maybe some tools like WinImage
, don't know which are the best alternatives.
A guide on how those dumps were done and how to contribute with more would be of great value to our site, maybe you can help us with that while we wait for Aral to shred some light on the subject.