A dei file extension is related Gerber design engineered interface file format.
DEI file extension - Gerber design engineered interface
What is dei file? How to open dei files?
File type specification:
The dei file extension is associated with the Gerber design engineered interface file format developed by the GSI Gerber Systems Inc. and used in PCB (Printed Circuit Board) desigining and industry.
The Gerber design engineered interface format seems to be obsolete.
This dei 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.
