Path: utzoo!utgpu!attcan!uunet!mcvax!ukc!warwick!rlvd!asw
From: asw@inf.rl.ac.uk (Tony Williams)
Newsgroups: comp.arch
Subject: Re: amusing opcodes
Message-ID: <3416@rlvd.UUCP>
Date: 9 Aug 88 17:25:16 GMT
References: <5458@ecsvax.uncecs.edu> <1876@looking.UUCP> <753@applix.UUCP> <3884@sequent.UUCP> <719@mcrware.UUCP> <5440@june.cs.washington.edu> <1988Aug7.013526.7798@utzoo.uucp>
Reply-To: asw@inf.rl.ac.uk (Tony Williams)
Organization: Rutherford Appleton Laboratory, Didcot. UK.
Lines: 23

In article <1988Aug7.013526.7798@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>For the purposes of comp.arch, let us at least stick to *real* opcodes,
>not imaginary ones (amusing though they can be...).
>
> ...
>Another real-life example is that the Burroughs 6700 series had some opcodes
>for interprocessor communication in multi-CPU systems.  There was one for
>atomic access to memory, which had some boring name.  The fun pair were for
>actually attracting another processor's attention:  there was one that
>interrupted *all* processors, and another that would give you the processor
>number of the current processor.  So you would set up some sort of message
>in shared memory and then interrupt everybody, and each processor would
>get its own processor number and then inspect the message to find out if
>it was the addressee.  The instructions were HEYU and WHOI, I'm told.

As I recall, there was also a variant known as the super-HEYU,
which could not be ignored.  Its mnemonic was ZAP.
-- 
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