Subject: Re: Serial setup.
To: None <netbsd-help@NetBSD.ORG>
From: Ty Sarna <tsarna@endicor.com>
List: netbsd-help
Date: 03/02/1995 07:05:32
In article <2F551ADB@ms-mail.datastorm.com>,
John Maier  <JohnAM@datastorm.com> wrote:
> 
> >Hmmmm dunno about your modems but the Netcomm ones I play with have an
> >option for locking the DTE speed (ATRxx where xx sets the DTE speed).
> 
> Sorry, the bulk (99%+) of all consumer modems are auto-baud detecting. 

Huh? All the >=9600 bps modems I've seen either provide DTE rate locking
or allow you to achieve effectively the same thing.  I've got some
Supras (both v.32bis and v.FC models) and two USR DSTs set up this way,
on two different types of systems.  In particular my news/mail system
(Sun3, SunOS 4.1) is set up this way with a Supra v.32bis modem, and
it's no big deal.  In fact, I think I'm using nearly the default (PC)
settings for this.  DTE stays at 19200 regardless of the rate of the
incoming connection. 

> Yes I realize this, and should have mentioned this.  However, most modems 
> will pulse CD low when carrier is lost and then go high again.  In my case, 
> long enough for BSD to terminate the session.   On a few modems, CD wont 
> even go back high, which in this case would be nice!  If security is an big 
> issue, this should be tested.

Supras allow this (&C1), as do most others, I think.

>  I think hardware availability is the issue here.  Most people have Superas, 
> Intels, Hayes, Practical Peripherals, etc. and want a way to use them 
> without shelling out lots of money for another modem.  Not to mention, all 
> of the modems that I've seen that support locked DTE are rather pricey 
> compared to their auto-baud detecting counter parts, and this is a 
> consideration to those who are using NetBSD as a hobby/learning OS.

I think you really need to consult your manuals again. "locked" (or near
equiv) DTE is availible on all of these, AFAIK. Most PC BBSes run this
way, and very few of them run anything my standard "consumer grade" modems.

> Now, if someone would tell me how to initialize the port at a specific baud 
> rate during boot (in the rc file) this whole security issue would go away! 
>  I guess if I don't get a response, I'll write a small app to accomplish 
> this feat. Something like:

Set it up the way you want and use AT&W (same on most modems). Works for
me.

FYI, my settings on the Supra are:

STORED PROFILE 0:
B1 E1 L0 M1 N1 Q0 T V1 W1 X4 Y0 %C0 %E1 %G1 \N3 &C1 &D2 &K3 &Q5 &R0 &S0 &X0 
S00:004 S02:043 S06:002 S07:050 S08:002 S09:006 S10:014 S11:095 S12:050 S18:000
S23:063 S25:005 S26:001 S36:007 S37:000 S38:020 S40:087 S46:136 S48:007 S95:000


-- 
Ty Sarna                "I thought you were wrong before, but compared
tsarna@endicor.com       to now you were right" -- Exit 57