Thanks for all the help.
Indeed, typing \"/\" from the keyboard during the INIT 5 sequence got me a login: prompt.
Next: What\'s the root password? (It\'s the only user guaranteed to be there.)
Is it blank? No.
Is it \"root\"? \"Root\"? \"admin\"? Any appropriate h4x0r spelling of anything obvious? \"sharp\"? \"zaurus\"? \"5600\"? No, no, no.
It was indeed the passcode that you give on start-up. (I never would have assumed that the default UI runs as root, but I guess it does.) Besides, the passcode consists only of digits, yielding a pretty small dictionary.
Now,.... Where\'s the pipe-symbol?
Thanks again!
,Doug