At 06:15 AM 11/4/98 -0800, you wrote:
>Hello all,
>ÊÊ I am working on a PIC based telephone project which will
>intercept and screen all incoming calls, without the phone ringing and
>conditionally, based the screening criteria,
>either issue a voice message or ring the phone and connect the phone to the
>incoming line.
>
>Can anyone point me to information on how to carry out the
>actual connect functions to the handset.Ê This is the only
>part of the project I haven't figured out.
>
>Thanks in advance.
>
>
>73,
>Dan Welch
>w6dfw@qsl.net
> 

I've been looking into this as well.  My theory is that most of the automated
calling services these days have about one second of silence after you pick up
the phone, but before you are connected to the salesperson.  I think it should
be possible to key off this delay to hang up on automated sales calls.  The
problem is getting the pic chip to answer the phone and to hang up at the
appropriate time (or to actually ring you if it is not a sales call).  In
asking around about this, everybody I heard from said the best book on the
subject was one that used to be sold by (believe it or not) Radio Shack.   I
remember that book and now regret not having bought one, but it is no
longer in
print.  If you can find someone with a copy, I'd like to have one too!

Best of luck with your project.

John, W2FS