Program mode from any phone, HOLD, #, 0, *, 8974
Press line key 4, keypad 29. The number in the far left of the display is the telephone port number. Press line key 2 to turn on speakerphone, press TRF to write the change. This takes you to the next memory block. Use the * key to move the cursor left, # key to go right. Move back to the memory block number (where 29 was) in the display, then press CNF to advance to the next telephone port number. Repeat the process for all of the phones.