Reading (a lot of) documentation from IBM it seems that a lot has gone
into the *nix side of z/OS and extra instructions and 64-bit
addrssability for data, but that the code itself still resides below the
bar, so that most AMODE 24 and 31 code from years ago will still
compile/assemble and run as is, or with minimal change.
Is that fair?
But if new code using 64-bit data is still loaded and executed below the
bar, and new instructions and extended registers handle the addressing
of data with 64-bit addresses, why is there an AMODE 64 at all? Is it
simply to indicate that a larger (DS 18D) savearea should be provided,
as it may be needed by the called program?
Thanks for any clarification you can offer.
Roops
