Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!udel!gatech!hubcap!ncrcae!ncr-sd!sceard!mrm
From: mrm@sceard.Sceard.COM (M.R.Murphy)
Newsgroups: comp.dcom.modems
Subject: Re: Anyone have a modem dialing out on two lines?
Message-ID: <952@sceard.Sceard.COM>
Date: 10 Oct 89 15:07:46 GMT
References: <1890.252E9E05@tlsi.FIDONET.ORG> <[25308f69:15.1]comp.dcom.modems;1@nstar.UUCP>
Reply-To: mrm@Sceard.COM (0040-M.R.Murphy)
Organization: Sceard Systems, Inc.  San Marcos, CA  92069
Lines: 36

In article <[25308f69:15.1]comp.dcom.modems;1@nstar.UUCP> akcs.larry@nstar.UUCP writes:
>> >I'm running QNX (Que-Nix) on a 286 with two phone lines.
>
>Too bad.  QNX is a dead end street with no support from any of the
>major softwar vendors - it took them 7 years to finally get Enable ported.
>  
>>I've run Unix and have found that no matter how hard you try, you can only
>>dial
>>out on one phone line when you've only got one modem.
>
>That's the bottom line.  I have called in from the office using V.32 - to
>V.32 (on this box running SystemV) then out the TB port using ProYam.  No
>biggie.

QNX(tm), UNIX(tm), MSDOS(tm). Makes no difference to the stated problem. If
you can trot down to your local Radio Shack(tm) and buy a DPDT(not tm)
relay and hook it up to two telco lines and your modem, and if you can either
drive it off one of the spare control lines on an existing board (without a
driver if you have a relay that doesn't take much poop to drive, or with a
transistor(too bad it wasn't tm:-) if it does), or beg, buy, or steal another
interface board and use a signal from it, then you can use one modem with two
phone lines for dialout if you can beg, buy, or write the software to flip the
signal and switch the relay. If you can't, then the problem becomes harder.
You could use two lines with one modem for dialin, too, by switching the relay
every few seconds under software control while waiting for RING or CD or
whatever you like. When the signal shows, connect away. Then the other line
can't be answered until the first call completes, but you did want to avoid
the purchase of a second modem, didn't you?

The solution can be as elegant or Rube Goldbergish as one wishes. Digital
switches come to mind, but it seems like an overkill. Send SASE(also not tm)
for circuit diagram and instructions:-)
--
Mike Murphy  Sceard Systems, Inc.  544 South Pacific St. San Marcos, CA  92069
mrm@Sceard.COM        {hp-sdd,nosc,ucsd,uunet}!sceard!mrm      +1 619 471 0655