I have no memory of why Ken used mt1 not mt0. Doug
may know.
I don't know either. Come to think of it, I can't remember ever
using tar without option -f. Direct machine-to-machine trasfer,
e.g. by uucp, took a lot of business away from magtape soon
after tar was introduced. Incidentally, I think tar was written
by Chuck Haley or Greg Chesson, not Ken.
Doug