I'm trying to read the PHILE and PHILE+ file systems (I have a floppy disk flux-level reader project, and someone has shown up with some weird m68000-based SBC running pSOS, which runs off floppies). The official documentation (the 'pSOS System Concepts' PDF) has just enough hints in it that I've managed to reverse engineer just enough of it to be able to read some files, possibly correctly, but there's a lot of weird numbers and edge cases I don't know anything about.
Does anyone have any pointers? Not just documentation, but existing tooling for creating and reading these filesystems would be invaluable too. I did see a web reference to one once but like an idiot I didn't save the link and now I can't find it again!