Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site rtech.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!mtuxo!mtunh!mtung!mtunf!ariel!vax135!cornell!uw-beaver!tektronix!hplabs!amdahl!rtech!mark From: mark@rtech.UUCP (Mark Wittenberg) Newsgroups: net.arch Subject: Re: Orthogonal addressing doesn't help multis. Message-ID: <495@rtech.UUCP> Date: Wed, 19-Jun-85 22:50:45 EDT Article-I.D.: rtech.495 Posted: Wed Jun 19 22:50:45 1985 Date-Received: Fri, 28-Jun-85 01:24:14 EDT References: <419@oakhill.UUCP> <6415@boring.UUCP> Organization: Relational Technology, Alameda CA Lines: 17 > > And furthermore, the orthogonal sequence is normally atomic... > > Mark Wittenberg > > This is untrue on machines I know of. Typical memory-to-memory > instructions do NOT lock out other memory cycles in between; this > requires a specific "test-and-set" or "compare-and-swap" instruction. I was thinking of the PDP-11 (eg, inc used the DATIO cycle) on which it is true (unless my brain has fogged beyond repair, which is possible -- it's been several years now). Can't think of any micros that do so, though. Thanks for pointing this out. -- Mark Wittenberg Relational Technology zehntel!rtech!mark ucbvax!mtxinu!rtech!mark