Return to BSD News archive
Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!yarrina.connect.com.au!warrane.connect.com.au!kralizec.zeta.org.au!not-for-mail
From: bde@kralizec.zeta.org.au (Bruce Evans)
Newsgroups: comp.os.386bsd.questions
Subject: Re: tty vs cua
Date: 13 Jul 1994 21:37:03 +1000
Organization: Kralizec Dialup Unix Sydney - +61-2-837-1183, v.32bis v.42bis
Lines: 60
Message-ID: <300jkv$kn2@kralizec.zeta.org.au>
References: <Cstx0K.7qL@usenet.ucs.indiana.edu>
NNTP-Posting-Host: kralizec.zeta.org.au
In article <Cstx0K.7qL@usenet.ucs.indiana.edu>,
Alec Habig <ahabig@bigbang.astro.indiana.edu> wrote:
>In repsponse to the various complainst about using tip/kermit on tty, and the
>clocal hack not working anymore, I decided to try using the cua device instead.
>However, a MAKEDEV tty* nets me the following devices :
>
> tty01
> tty02
> cua03
>
>The tty's are correct (I've got a slightly twisted setup), but why on earth
>cua03?
Under FreeBSD-1.1.5 you should get the following devices:
tty00 ("hardwired")
tty01 ("hardwired")
ttyd2 cua02 (bidirectional pair)
ttyd3 cua03 (bidirectional pair)
plus some control devices.
>Ok, sez I, I'll just MAKEDEV cua02 (my modem). Bzzzt. It seems that
>the "make tty" and "make cua" parts of the MAKEDEV script are mutually
>exclusive. Each section rm's _all_ tty's and cua's before making anything! So
>using MAKEDEV as written will land you either tty's or cua's, not both.
Note that you get ttyd's with cua's, just not tty0's. The inconsistencies
are for historical reasons (these are the old names, and shell scripts might
refer to them). There is no longer any need to distinguish ttyd's from
tty0's, and never was a strong need to not have cua's independent of tty's
(you might want to control access to cua's by not having them, but for
that it is most convenient if cua's are made independently of tty's), so
it would be better if MAKEDEV created by default:
ttyd0 cua?0 (bidirectional pair)
ttyd1 cua?1 (bidirectional pair)
ttyd2 cua?2 (bidirectional pair)
ttyd3 cua?3 (bidirectional pair)
where '?' is a suitable letter ('0' is misleading).
>I was under the impression that cua's were simply another incarnation of the
>tty's. Why can't they coexist?
In FreeBSD-1.1 it was because the bidirectional devices had more bugs so
it was best not to use them unless they were required.
>Is it safe to hack MAKEDEV to let me build
>cua02 along with my tty's?
Safe but unnecessary.
>... And why on
>earth was cua03 built when I made tty* - sio3 is even commented out in my
>kernel!
MAKEDEV doesn't know which devices are actually configured.
--
Bruce Evans bde@kralizec.zeta.org.au