On Wed, Jun 24, 2020 at 2:34 PM Greg A. Woods wrote: > > As far as I can remember Multics didn't really have the concept of a > "mount point". All storage was single-level, i.e. segments (equivalent > in some respects to inodes, but they are also actually the value of the > segment register in the virtual memory hardware), and so files were > either physically in memory or paged out on physical disk devices or > similar, or even out on tape. Where they actually resided was entirely > and permanently hidden from the user. What was called the "filesystem" > was a form of database representing a hierarchical namespace which > pointed at all the known segments (files) regardless of where they were > actually stored. > > Coming to it from a Unix perspective, it's like all storage (core, disk, tape) is mmap()ed. The segment-name database then is just an index relating symbolic names to particular memory locations. It all feels very upside-down to me, but that's probably because I grew up in Unix and never actually used a Multics system until I emulated one with dps8m. Adam