Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watnot!watmath!clyde!cbatt!ihnp4!houxm!hjuxa!catnip!ben
From: ben@catnip.UUCP
Newsgroups: comp.dcom.modems
Subject: Re: more on 2400 baud modems
Message-ID: <470@catnip.UUCP>
Date: Mon, 16-Feb-87 19:54:02 EST
Article-I.D.: catnip.470
Posted: Mon Feb 16 19:54:02 1987
Date-Received: Tue, 17-Feb-87 22:49:52 EST
References: <189@forbrk.UUCP>
Reply-To: ben@catnip.UUCP (Bennett Broder)
Distribution: na
Organization: The Broder Residence, Holmdel, NJ  07733
Lines: 74


In article <189@forbrk.UUCP> mats@forbrk.UUCP (Mats Wichmann) writes:
>Thus, I need my line to be bidirectional - both incoming and
>outgoing calls. The system is one of our own boxes, running
>V.2 (but with the uucp/cu code out of V.3, i.e. HoneyDanBer).
>
...
>just got the Hayes 2400 baud modems they ordered (against my
>recommendation), and sent one up here. Now we are originate-only
>(in other words, now it all goes on my phone bill).
>
>Why? The Hayes "Smartmodem" has "a few" problems (besides just
>the fact that it is a Hayes). 
>Problem 1: the modem has a result code sequence which is activated
>    for answered calls as well as originated calls. This is
>    wrong - the result codes should only come back when I
>    originate a call. I don't want to be sent "RING" and
>    "CONNECT" when someone calls me.

This should not cause a problem on Unix machines if the modem is correctly
cabled and configured.  Explanation:  Hayes modems send the "RING" and
"CONNECT" messages *before* they raise the "CD" signal on pin 8 of the
serial port.  Most Unix systems will ignore input on ports with modem control
if this signal is held low, so getty will never see "RING" or "CONNECT."
Make sure that the carrier detect signal is not strapped high, either with
wire or dip switches/cmos.  And make sure that modem control is enabled on
all ports used for modem logins.  (See the info on CLOCAL in TERMIO(7), you
want modem control on for incoming lines, off for outgoing lines.  I
don't have a system with uugetty, but I'd be surprised if it doesn't do
this right)

>Problem 2: the modem does automatic baud rate detection on both
>    call originate and call answer. This is not what I want;

This is a bit misleading.  When used in originate mode, the Hayes adjusts
to the speed of *your* system.  It will not change rates if your dial in
to a machine that wishes to use a different rate.  When used in answer
mode, the Hayes autobauds to the speed of the calling modem.  On a Unix
system, the caller is then free to cycle through the speeds in gettydefs,
on a non-unix machine (such as a PC), the communications software can
detect speed from the "CONNECT speed" message, which is sent in the
original baud rate, prior to switching to the new speed.

>    I want the receiving modem to match my originate speed if
>    possible. If not possible, I want to terminate the connection
>    and try again at another speed (actually, I want my
>    Systems file to determine which speed to try first, and
>    whether to try again at a different speed). When *I*
>    am the receiving modem, I want to select the same speed
>    as the modem the called me; the guy on the other end can
>    then cycle through my gettydefs entries until he finds
>    the right baud rate uugetty. Simple, right?

The Hayes does *exactly* what you describe above.  If yours doesn't,
it is broken.

>This is *not* a request for help (I can solve 1) without too much
>headache and don't yet have an answer for 2) ). Instead, I want
>to stimulate some discussion of whether a particular modem
>works the way the user needs it to. I turn thumbs down on the
>Hayes because it does not fit my need (although I can't swap it
>out for something different, unfortunately).

I have been using Hayes and Hayes compatible modems on Unix boxes
(including this one) for several years now.  I think most of your
complaints stem from not knowing how to use a Hayes with your system
(not to mention an unjustified prejudice against this make), rather
than an actual deficiency in the modem.

-- 

Ben Broder
{ihnp4,decvax} !hjuxa!catnip!ben
{houxm,clyde}/