I know that z/OS STORAGE OBTAIN will never return a block of storage with 2GiB <= address < 4GiB. But what's the rationale for this? ISTR that I once knew, but I've forgotten, or always misunderstood. Is there a superstitious phobia of having bit 32 of a 64-bit address be 1? If so, isn't 6GiB <= address < 10GiB similarly offensive? Is it because 2GiB <= address < 34GiB is dedicated to Java?
-- gil
