A 7lsd file extension is related to the @Think C Debugger. Probably obsolete product.
7LSD file extension - @Think C Debugger data
What is 7lsd file? How to open 7lsd files?
File type specification:
The 7lsd file extension is associated with the @Think C Debugger a debugging tool for source codes written in C programming language.
The 7lsd file stores various data used for internal purposes of the app.
The @Think C Debugger seems to be obsolete product.
This 7lsd 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.