Program objects on DASD storage

Unlike the load module, whose format is documented and universally available, the format of the program object is NOT externalized. The binder API should be used to access program data.
Consistent with all data in PDSEs, program objects are organized in 4KB blocks, making them accessible by both the binder and loader via DIV (Data in Virtual) access mechanisms. The minimum length of a program object is 4KB.
When saving a program object in PM1 format, all uninitialized text in a program object (for example, DS space in a program) is written to DASD as binary zeros. DS space is not written to DASD for later program object formats.
Program objects cannot be in scatter-load format.
IEBCOPY load/unload functions will process program objects with NO change to the format, that is, it remains the same as it is on DASD.