A psa file extension is related to the Pretty Simple Archive and used for its archive files.
PSA file extension - Pretty Simple Archive archive
What is psa file? How to open psa files?
File type specification:
The psa file extension is associated with Pretty Simple Archive, an old compression program by Serge Pachkovsky. It was distributed under GNU license, but its probably no longer available/distributed.
The psa file stores archive created by Pretty Simple Archive.
This psa 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.