In <[EMAIL PROTECTED]>, on
09/05/2005
at 09:09 PM, mary george <[EMAIL PROTECTED]> said:
>Can anyone tell me where I can find clear explanations and difference
>between the following:
Any unit of work is associated with an address space called the home
address space. MVS initially gives a unit of work control with the
control registers for primary and secondary pointing to the home
address space. There is a mode bit controlling whether to resolve
addresses[1] using the primary or secondary address space.
The old cross-memory services relied on setting the secondary address
space, moving data with cross-memory instructions and switching
between primary and secondary modes. With the advent of AR mode, the
old mechanisms are anachronisms that are present only for
compatibility with old code.
I'd advise you to read up on AR mode in PoOps and the Addressability
Guide, and to just skim the descriptions of primary and secondary.
[1] Except for cross-memory instructions and instructions in AR mode
that specify a non-zero AR number.
--
Shmuel (Seymour J.) Metz, SysProg and JOAT
ISO position; see <http://patriot.net/~shmuel/resume/brief.html>
Is z/OS put together with DUCT tape?
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