Specifying CMPAT=NO in a PSB

Problem:

Whilst running an IMS BMP job, the BMP program receives the I/O PCB address EVEN though 

  CMPAT=NO

is specified in the PSB.

Resolution:

The compatibility option instructs IMS to generate an I/O PCB for all uses.  This is true even when running the PSB in an environment where an IOPCB is not used, for example batch or CICS. 

If CMPAT=YES is specified, PCB(1) will always be the IOPCB. 

If CMPAT=NO is specified, PCB(1) will be the IOPCB only for MPP and BMP programs. 

In batch and CICS, PCB(1) will be the first DB PCB.