.1-step is Iomega backup
Key Features: .1-STEP File Extension
What is an .1-STEP file?
The 1-step file extension is used by Iomega backup software distributed with some ZIP or JAZ drives.
The 1-step file contains backup data.
The ZIP and JAZ drives as well as software for them are discontinued products.
This 1-step 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.