VMS vs. UNIX file system

[Guy Harris]

> vms has file attributes directly associated with the file.  qio does
> read virtual blocks - but you can't easily convince rms to read a file
> in some mode other than the mode the file was created with.

As I remember, the VMS file attributes are maintained, but not really used, by
the code that I would refer to as the VMS file system (the ACPs or "extended
QIO processors" or whatever they call the new stuff they added in recent
versions).  I think there are QIOs (perhaps undocumented) that RMS uses to
fetch and store those attributes.