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From: bob@obiwan.uucp (Bob Willcox)
Newsgroups: comp.os.386bsd.misc
Subject: Re: Using the sio ports for terminals w/o modem ctl signals
Message-ID: <CCE9EA.2z1@obiwan.uucp>
Date: 27 Aug 93 01:27:31 GMT
References: <CBv07B.Hzy@willcox.uucp> <CBvvIG.7vB@obiwan.uucp> <1993Aug17.173025.477@fcom.cc.utah.edu> <25br95INNg7e@kralizec.zeta.org.au>
Organization: Bob's Place, Austin TX
Lines: 67
In article <25br95INNg7e@kralizec.zeta.org.au>,
Bruce Evans <bde@kralizec.zeta.org.au> wrote:
>In <1993Aug17.173025.477@fcom.cc.utah.edu> terry@cs.weber.edu (A Wizard of Earth C) writes:
>
>>In article <CBvvIG.7vB@obiwan.uucp> bob@obiwan.uucp (Bob Willcox) writes:
>>>... a brain-damaged board that does not have the DTR/DCD signals
>>>available ...
>>>As you can see, the DTR/DCD signals never leave the board. As far
>>>as I can tell, this makes the board useless for modems, but all ...
>>>
>>>It sounds (from Bruce's posting) that by setting CLOCAL (and keeping
>>>it set) sio will work with this setup. Unfortunately, I have not
>>>had the time to work on this lately.
>
>Are you (Bob) sure that the board is brain-damaged enough to require
>any fixes at all? If the board has xx(x)50 chips, then each port has a
>DCD input. It would have to be a very braindamaged board to leave the
>input unconnected. If the board has special chips that emulate an
>xx(x)50, then the chips need not have DCD inputs, but the xx(x)50
>emulation should probably pretend that carrier is always present.
Actually, I am no longer certain that it is brain-damaged (at
least not as I originally thought). It seems that the adapter
presents a DCE interface rather than DTE as I had expected (and
always seen before). Only after discovering that it worked when
I accidently connected one of my terminals and forgot to include
a null-modem in the line did I get suspicious. A more careful
examination of the manual that came with the card revealed that it
is indeed wired as a DCE device. I now have the terminals working
with the following (3 wire + shield) cable wiring:
Terminal End BB1008 End
DB25F (DTE) DB25M (DCE)
SIG PIN WIRE PIN SIG
TD 2 ------ Red ------ 2 TD
RD 3 ----- Green ----- 3 RD
GND 7 ----- Black ----- 7 GND
/-- 6 RTS
\-- 20 CTS
1 ----- Shield ---- 1
Note that the RTS/CTS signals are on the DB25 pins usually assigned
to DSR/DTR. I thought this rather bazaar but this is how they show
it in the manual (I have not attempted to verify it).
From the manual:
``Populated with two quad UART chips with FIFO buffering (each
equivalent to four NSC16C550s).''
I did not have to set CLOCAL to get this to work. There are no
jumpers on the board to control DCD. I suspect that it is being
asserted unconditionally.
I suspect that, given the restrictions on signals available with
this board and that it is configured as a DCE device, that it is
primarily targeted to installations involving local terminals.
It looks like my problem (this one anyway) is solved. I want to
thank everyone for their input and ideas.
--
Bob Willcox ...!{rutgers|ames}!cs.utexas.edu!uudell!obiwan!bob
Phone: 512 258-4224 (home)
512 838-3914 (work)