I don't think MSDOS did the following aspect of zozbot123's post: > In fact, you could even generalize this, by asking the user to introduce some specific medi

I don't think MSDOS did the following aspect of zozbot123's post: > In fact, you could even generalize this, by asking the user to introduce some specific media (identified by label) when some mountpoint is accessed, even if no operations were actually in progress. In MSDOS the paths were like "A:FOO.TXT" as far as I remember. That means you had no facility, as a program, to request the user insert a particular disk identified by a particular label. For example, on RISC OS (but not on MSDOS) you could implement a program to copy files between two disks by simply reading from the disk with the source label and writing to the disk with the destination label. Even on a machine with a single disk drive. The OS would request the user insert the source and destination disks as appropriate.