Hi,
With the MIC in the 1st MPC slot then the numbering goes - x/0/0, x/0/1, x/1/0, x/1/1 (Where x is the MPC Slot number), and with it in the second MPC slot then it goes x/2/0, x/2/1, x/3/0, x/3/1 (again with x as the MPC Slot number).
Cheers,
Mike