how to create stream pipe (S5R3) ?

[Richard Stevens]

I'm trying to figure out how to create a "stream pipe" with System 5,
Release 3.2 (386 version).  The streamio(7) man page says the only
way to pass a file descriptor is using these, but I can't find
any reference as to how a stream pipe is created.  In Steve
Bellovin's "Session TTY Manager" paper from the San Francisco
Usenix, he describes the "strange" way they're created under
Research Unix, but I can't find any mention of /dev/spx in my
System 5 manuals.

	Richard Stevens
	Health Systems International, New Haven, CT
	   stevens at hsi.com
           ... { uunet | yale } ! hsi ! stevens