If you are looking for specific telephone info, feel free to e-mail me.  I
have been working for several years on different telephone interface
projects.  Mouser electronics 1-800-346-6873 (I do not work for these
folks)  has a telephone coupler for as little as $1.52  part # 42TL016.  If
you take the phone line in through .22Uf caps into the coupler, and then
place two 3.5v zener diodes arrows pointing away from each other
across the lines to clip the ring voltage, you will then be able to use the
phone line with the pic chip ,etc.. and make the phone company happy.


line in----.22 cap-----|                                    | ------|--------
                                 |                                    |
 zener
                                 | coupling transformer  |         |
                                 |                                    |
 zener
line in----.22 cap-----|                                    | ------|--------

  If anyone has code for a DTMF decoder for a pic chip, I am presently
looking for help in this area,   Thanks....

John Moeller