Article View: comp.lang.asm370
Article #190Storing into the CAW (was: (none))
From: C.E. Thompson
Date: Fri, 20 Oct 1989 14:56
Date: Fri, 20 Oct 1989 14:56
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1468 bytes
In article <8910181519.AA05760@brazos.rice.edu>
PERSHNG@YKTVMH.BITNET ("John A. Pershing Jr.") writes
>CMS normally runs all programs in (virtual) Supervisor State -- if you
>find that you are in problem state, then there is something amiss.
>
>However, to try to keep you from shooting yourself in the foot, CMS
>protects its own storage areas with a Storage Key of x'F', and sets all
>"user" pages to a Key of x'E'. This is probably why you are having
>difficulty storing into the CAW. There are a number of ways to get
>around this annoying behavior ...
All of which he gives correctly. However, there is another point to
keep in mind: doing your own I/O instructions, and relying on things
like the CAW, is going to stop working when (if) you have an XA mode
virtual machine. It is better, where possible, to use the synchronous
I/O diagnose instructions.
Chris Thompson
JANET: cet1@uk.ac.cam.phx
Internet: cet1%phx.cam.ac.uk@nsfnet-relay.ac.uk
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arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!sun-barr!cs.utexas.edu!uunet!mcsun!ukc!cam-cl!cet1References:
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!sun-barr!cs.utexas.edu!uunet!mcsun!ukc!cam-cl!cet1 From: cet1@cl.cam.ac.uk (C.E. Thompson) Newsgroups: comp.lang.asm370 Subject: Storing into the CAW (was: (none)) Message-ID: <1364@scaup.cl.cam.ac.uk> Date: 20 Oct 89 14:56:23 GMT References: <8910181519.AA05760@brazos.rice.edu> Sender: news@cl.cam.ac.uk Reply-To: cet1@cl.cam.ac.uk (C.E. Thompson) Distribution: inet Organization: U of Cambridge Comp Lab, UK Lines: 20