In <[EMAIL PROTECTED]>, on 02/10/2006
at 10:07 AM, Anne & Lynn Wheeler <[EMAIL PROTECTED]> said:
>in the initial translation from "real-storage" MVT operating system,
>to VS2-SVS ... single virtual storage, a single 16mbyte virtual
>address space was created and some paging code was hacked onto the
>side of MVT ... and ccw translation routine from CP67 (CCWTRANS) was
>glued into MVT. In effect, for most of MVT, it was as if it was
>running on 16mbyte real machine (and there was little awareness that
>it was running in a virtual machine environment.
There were several things that made it visible.
1. TSO swapping
2. The presence of *all* SVC modules in the address space.
3. The (unfortunate, IMHO) ABEND S0C4 that did *not* indicate
a PI type 4.
>The real machine might have 4mbytes of real storage,
Ours only had 2 MiB.
>The real machine might have 4mbytes of real storage, but there was a
>total of 16mbytes of virtual storage defined.
More if you took TSO into account.
>3081 and 370-xa introduced 31-bit (virtual) addressing and also
>generalized the duall-address space support with "access registers"
>and "program call".
No. PC came in with the 303x, prior to XA, and access registers came
in with the 3090, later than XA and part of ESA.
--
Shmuel (Seymour J.) Metz, SysProg and JOAT
ISO position; see <http://patriot.net/~shmuel/resume/brief.html>
We don't care. We don't have to care, we're Congress.
(S877: The Shut up and Eat Your spam act of 2003)
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