PDP11 UNIXRT ldp" files

I wonder ... is UNIX-RT still alive? Or is someone else just using data formats close enough to fool the popular "file" command and buttociated magic data file, consistently?

I saw a certain piece of networking gear stuff its own configuration in a file that looks like binary (not much ASCII in there) to someone like me who's only used to having binary and human-readable files ... and gets recognized as "PDP-11 UNIX-RT ldp".

After a bit of searching I found that other people had gotten similar stuff out of other makers' network equipment too. And that still more people mention PDP and UNIX a lot in the Linux Documentation Project ;-(

A certain Martin McCormick tried to read such a floppy that came out of a 3Com device, apparently; mine's a Zyxel and drops files across the network with FTP.

Anyone care to enlighten me as to what the "UNIX-RT ldp" part means, at least? Surely someone around here has seen it before...?

Anyway, the file structure doesn't look all that complicated - which probably means that there isn't enough information in there to make any real sense of the contents...

-- #Not speaking for my employer. No warranty. YMMV.