A $d file extension is related to the TR-DOS data file format.
Software that open $d file
$D file extension - TR-DOS data file format
What is $d file? How to open $d files?
File type specification:
TR-DOS data file format (Hobeta files)
Hobeta files store only one file of a virtual TR-DOS disk image. The file name contains the letter that is used to describe the file type: $B = Basic program, $C = Code, $D = DATA array.
This $d 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.
The default software associated to open $d file:
Company or developer:
Vladimir Kladov
EmuZwin is a ZX-Spectrum 128 and 48 emulator for Windows. Still available for download, but seems it was meant for earlier versions of Windows.
List of recommended software applications associated to the .$d file extension
Recommended software programs are sorted by OS platform (Windows, macOS, Linux, iOS, Android etc.)
and possible program actions that can be done with the file: like open $d file, edit $d file, convert $d file, view $d file, play $d file etc. (if exist software for corresponding action in File-Extensions.org's database).
Unspecified and all other actions for computer programs working with $d file - TR-DOS data file format
Click on the software link for more information about EmuZwin. EmuZwin uses $d file type for its internal purposes and/or also by different way than common edit or open file actions (eg. to install/execute/support an application itself, to store application or user data, configure program etc.).