An ac1d file extension is related to AC1D-DC1A Packer module file format.
AC1D file extension - AC1D-DC1A Packer module
What is ac1d file? How to open ac1d files?
File type specification:
The ac1d file extension is associated with the AC1D-DC1A Packer that allows users to package sound modules on Amiga 32-bit computers developed by Commodore.
The .ac1d file stores packed module.
The AC1D-DC1A Packer was developed by Carsten Sørensen of the demo group "Anarchy".
This ac1d 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.