Where can I find what I have to do to add a door phone to an Elite 192. Do I need a special card for this? I bought a copy of the manuals off the net and they look like poor photocopies of the original. All it does is list all the memory blocks. Where can I find a book that actually explains how to program the system? I've done many other bix PBX systems like system 85, 75, dimension, etc. Just havent got the hang of these car's and cap's yet