IOAENV Assembler Macro
The IOAENV macro initializes the IOA environment by performing the following functions:
- Locate an area for the MCT and builds member IOAPARM into it.
 - Provide parameters for dynamic allocation.
 - Optionally build requested xxxPARMs.
 - Optionally build requested xxxPLEXs.
 - Optionally open LOG or LOG-in-Memory.
 - Optionally initialize the messages environment, optional wishes environment, and trace options.