Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site watdcsu.UUCP Path: utzoo!watmath!watdcsu!herbie From: herbie@watdcsu.UUCP (Herb Chong [DCS]) Newsgroups: net.lang Subject: Re: Runtime trapping of program bugs Message-ID: <824@watdcsu.UUCP> Date: Sun, 13-Jan-85 17:03:15 EST Article-I.D.: watdcsu.824 Posted: Sun Jan 13 17:03:15 1985 Date-Received: Mon, 14-Jan-85 01:58:47 EST References: <5143@rochester.UUCP> <19@decvax.UUCP> <481@ecsvax.UUCP> <6854@watdaisy.UUCP> Reply-To: herbie@watdcsu.UUCP (Herb Chong [DCS]) Organization: U of Waterloo, Ontario Lines: 24 Summary: In article <6854@watdaisy.UUCP> ndiamond@watdaisy.UUCP (Norman Diamond) writes: >The Diagnose machine instruction (the real one) might generate bad parity >among its tests, but a problem program like Watfiv would not be able to take >advantage of it. > >-- Norman Diamond the in a VM environment, a DIAGNOSE instruction is also known as a hypervisor call (as opposed to a supervisor call). it traps to the real operating system as opposed to the virtual one. the DIAGNOSE instruction issued by the CP component of of VM can do these things, but in a VM, it will always go to the operating system and not the hardware. incidentally, the DIAGNOSE instruction is a machine instruction that is defined to be model dependent. it is supposed to call up microcode for debugging the hardware and things like that. Herb Chong... I'm user-friendly -- I don't byte, I nybble.... UUCP: {decvax|utzoo|ihnp4|allegra|clyde}!watmath!water!watdcsu!herbie CSNET: herbie%watdcsu@waterloo.csnet ARPA: herbie%watdcsu%waterloo.csnet@csnet-relay.arpa NETNORTH, BITNET: herbie@watdcs, herbie@watdcsu