Files with EDT extension might also be settings for early VAX based computers.
EDT file extension - VAX EDT editor default settings file
What is edt file? How to open edt files?
File type specification:
The EDT file extension is used by VAX. "VAX" was originally an acronym for Virtual Address extension, both because the VAX was seen as a 32-bit extension of the older 16-bit PDP-11 and because it was (after Prime Computer) an early adopter of virtual memory to manage this larger address space. Early versions of the VAX processor implemented a "compatibility mode" that emulated many of the PDP-11's instructions, and were in fact called VAX-11 to highlight this compatibility and the fact that VAX-11 was an outgrowth of the PDP-11 family. Later versions offloaded the compatibility mode and some of the less used CISC instructions to emulation in the operating system software. The plural form of VAX is usually VAXes, but VAXen is also heard.