RT-11 .DPA and .DPY files

[Chuck Guzis]

I've just finished processing a bunch of RX01 and RX02 RT11A disks.
The files on the RX01 floppies are of type .DPA and those on the RX02
ones, DPY.  No files of any other type in the whole collection.

I have no other information, but I suspect that these are plotter files.

Both types seem to start with the same prefix bytes, for example:

06 00 f0 00 40 00 00 01  00 1e ff ff 00 00 00 00

Does anyone have a guide to how these files are structured?

Thanks,
Chuck