I'm not sure of the point of this mine-is-bigger-than-yours argument, but: The earliest stream-I/O-system-based tty driver I'm aware of was already in the Research kernel when I interviewed at Bell Labs in early 1984. I have a vague memory that it was a couple of years older than that, and was first implemented in a post-V7 PDP-11 system; also that I had heard about it first at a USENIX conference in 1982 or 1983; but I cannot find any citations to back up either of those memories. I do know that I'd heard of it while I was still working at Caltech, because I remember thinking about what a good idea it was and about possibly trying to do my own version of it, but I never did. I left Caltech at the end of June 1984, spent the following month touring nearly the entire Amtrak long-distance network in a single long reservation (it was possible to do that with surprisingly few overnight stops off the train in those days), and started at Bell Labs at the beginning of August. Norman Wilson Toronto ON