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. -- --------------------------------------------------------------------------- Tony Williams |Informatics Division JANET: asw@uk.ac.rl.vd |Rutherford Appleton Lab Usenet: {... | mcvax}!ukc!rlvd!asw |Chilton, Didcot ARPA: asw%vd.rl.ac.uk@nss.cs.ucl.ac.uk |Oxon OX11 0QX, UK