CPM (Central Processor Module) The  CPM module is equipped  standard  in  KSU1.   This board contains  all circuitry required to control the  fully  equipped  DX-80.   The  system  uses  the CPM to  perform all digital  voice switching and call processing  data switching. The  CPM has one ribbon  cable connector for connection  to the KSU1  408M and five  (5) connector sockets for connection of the system built-in modem,  voice processor,  and second  cabinet (KSU2).  Since  the CPM comes installed inside of KSU1 the CPM ribbon cable is already  in place and connected  to the KSU1-408M J5 socket.   Assuming the orientation of the  KSU1 cabinet is  installed on the wall; the  two horizontal connector  sockets in the upper  right corner  of the CPM are for  the MDM (Modem  Module).   The  connector socket labeled “2nd  Cabinet”  is for connection  to the KSU2-408E if that  expansion is  required.   The  remaining two connector sockets on the  CPM, one at the  left side, the other at  the right  side are for  the  voice processor  solution.   Note:   The  voice processor solution can be any of  three possible choices:  AAM,  7271C,  or 7270C.