A dseg file extension is related to the Stuffit DropSegment data format. Probably obsolete.
DSEG file extension - Stuffit DropSegment data
What is dseg file? How to open dseg files?
File type specification:
The dseg file extension is associated with Stuffit DropSegment, some older now discontinued product for Macintosh computers.
Most likely some old format without support. No further information could be found.
This dseg file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.