On Fri, 21 Jul 1995
Eero Laurila <[log in to unmask]> wrote:
 
> I remember seeing this error when the system for some reason was unable
> to fopen a modem port... in my case the reason was some of the required
> modem signals being down...  Do you have the port configured with modem
> profile?
 
When the modem and port have the best configuration for dial-in.  They often
cannot be used for dial-out.  Although some modems can pull special tricks such
as presenting DSR almost all the time and pulsing it when someone disconnects,
not all popular modems do this.  I have found (the hard way) that a modem
pulsing DSR is not always enought to get a dial-in session logged-off when the
line disconnects.
 
As best as I can tell for dial-out, a modem needs to present both DSR and CD in
order for a program to open the port:  Why does the modem have to lie?  If there
is no connection, DSR and CD should not be true.  What we need is a trick
(supported) that will allow writes to the port regardless of the state of DSR
and CD.  Predictive seems to know some trick because it can write to ports that
I cannot.  Eero can you help?  (Even if the trick is not supported, may I know?)