remote access to edit buffer

[Eliot Handelman]

If I'm editing a buffer and for some reason (say, my modem flakes out)
I have to switch terminals, is there some way to get a hold of the buffer
from another shell? Related question is, if I kill the edit job how do I
ensure an autosave? What's going on when vi autosaves when the machine
crashes?

Eager to have these mysteries resolved, I am faithfully yours.