Stty/Gtty on System III and PC/IX?

[Guy Harris]

Well, "stty" and "gtty" were all you had on V6.  V7 added "ioctl", and
System III picked it up.  "stty" and "gtty" were provided as library
routines on V7, but I think the system calls were there, although no library
routine invoked them; "stty" did a TIOCSETP.  S3 provides "stty" and "gtty"
as system calls; the kernel code maps them into TIOCSETP and TIOCGETP.

HOWEVER, it's *not* doing a V7-style TIOCGETP/gtty or TIOCSETP/stty!  It's
doing a UNIX/TS 1.0 or PWB/UNIX 2.0 TIOCGETP/gtty or TIOCSETP/stty, which
is a horse of another color (and, by the lemma, that doesn't exist :-)).
You do NOT want to do "stty", "gtty", "ioctl(TIOCGETP)", or "ioctl(TIOCSETP)"
under System III if you can possibly avoid it.

System III comes from a different line of development than V7.  It is 95%
based on the same code as V7, but the tty driver developed differently.
It is backwards-compatible with UNIX/TS 1.0 and PWB/UNIX 2.0.

It is possible to replace the TS 1.0/PWB 2.0 compatibility stuff with
V7 compatibility stuff; it works about 95% of the time - RAW mode is the
only really nasty part, because RAW mode affects several different parts
of the "termio" structure, and does so in a non-invertable fashion.

	Guy Harris
	sun!guy (ignore any other addresses)