On 12/11/15 4:31 PM, Clem Cole wrote:

First, the device # should be usable from the command line, i.e. tar cv0 foo

As for mt, it was written for the tape device and in those days most of us had at least one 9-track device. I have no memory of why Ken used mt1 not mt0. Doug may know.

Clem,

Thanks, that'll teach me to read the man pages more carefully even when the command is familiar in its modern form. Your tip about the device number caused me to check. Sure enough, it's in the documentation :). I am so impressed with the durability of the original documentation. These were written some 40+ years ago, and they're still amazingly useable by folks like me who have only worked with OSes created since the 1990's (of course, not entirely without help).

man tar
...
0,...,7 This modifier selects the drive on which the tape
is mounted. The default is 1.
...

-will