Lucky you.

Considering the 800 D-I-D is a Trunk Module, then doing the swap you are talking about will not cause you great programming grief.

Here's how you would want to do this:

Before doing any thing, PRINT the EXTENSION DIRECTORY, plus the CALLING GROUP Info and then do a BACK UP to the FLASH CARD, after that:

(1) Power the system down

(2) Remove the 800 D-I-D and the 016-TRR

(3) Power the system back up

(4) Do a board renumber

(5) Power the system down again

(6) Install the 016-TRR into Slot 4

(7) Power the system back up again

(8) Do another board renumber

(9) Again, print the Extension Directory to double check that your 016 Extensions have not changed extension numbers.

(10) Next, print the Group Calling info to insure that your Voice Mail Ports are still numbered correctly and that they still retain their VMI settings. (I am certain they will)

(11) Again, Power the system down

(12) Install the 408 ATL Module

(13) Power the system back up again.

(14) Do another Board Renumber

That should make it work for you with virtually no programming. (Except to determine what the ATL Extension numbers are.)

Of course, if it goes south, you can put it all back like it was when you started and do a RESTORE from the FLASH CARD BACKUP you created before STEP 1.

RULE NUMBER 2, "THINKIN' WON'T GET IT, YOU GOTTA KNOW!" RULE NUMBER 3, if you need TIER-3 SUPPORT on a LEGEND or MAGIX, go to http://home.comcast.net/~merlinman -