Decadent Singularity

Filesystem Path Formats
I was curious where the RISC OS `device.path.leads.to.file` style path format came from.
Apparently it came from the classic IBM OSes.

Multics   >device>path>leads>to>file.ext
Unix      /device/path/leads/to/file.ext
MIT ITS   device:path;leads;to;file ext     extension is separate from filename
Amiga     device:path/leads/to/ext.file     extension comes first
CP/M      device:\path\leads\to\file.ext
DOS       device:\path\leads\to\file.ext    yes, MS "borrowed" a lot from CP/M
MacOS     device:path:leads:to:file.txt     System 1 to Mac OS9
VMS       device:[path.leads.to]file.ext    also allows ext.gen - versioning
TOPS-20   device:<path.leads.to>file.ext    also allows ext.gen - versioning
TENEX     device:<path.leads.to>file.ext
IBM zOS   device.path.leads.to.file.ext
RISC OS   device.path.leads.to.file         extension is separate from filename
                                            DOS files .ext is renamed to /ext
                                            while ROS files get ,HEXCODE suffix
                                            when transferred to DOS or over
                                            network, without MIME types.

Note that MIT ITS/VMS/TOPS-20/zOS/RISC OS allow several named root dirs for a device.
I.e. single device could have several filesystems.

Typically they are specified as DEVICE$FILESYSTEM

So basically, the `.` format comes from IBM. Unsure if the `.` in C based language was also based on it.

NOTE: MIT ITS apparently too allowed referencing separate partitions of the device
https://github.com/PDP-10/its/blob/master/doc/NITS.md

:MIDAS DSK0:.;NITS BIN_SYSTEM; ITS

Here `:.;` I think stands for the default partition. On RISC OS that would be :$.

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