I'll have to give that a try, according to the book it says to access the channels via buttons 13 thru 18. I just looked at my Vodavi Mach 1 programming cd and it does show them via buttons 1-6 as you've pointed out. I always thought my hardcopy and the cd where the same, apparently not. In the book it also shows a circuit setup with some caps, resistors and external power supply. Is that really necessary to make the moh work via a CO port. Will it work with either 24 or 48 volts? Thanks for all your help.