Aucbvax.2077 fa.works utzoo!duke!decvax!ucbvax!gaines@RAND-UNIX Sat Jul 4 10:03:45 1981 Re: Addressing and File Accessing It is little known, but the new versions of the Honeywell 6000 have a memory management unit, internally known as NSA (for New System Architecture, I think), which makes the machine a form of capabilities machine. It is elaborate and baroque, but underneath are some very powerful ideas. The architecture supports multiple independent domains (where a domain is a set of addressing capabilities), such that a process can consist of many domains. Honeywell is slowly attempting to extend the old GCOS-III operating system to take advantage of this, and the new version is being called GCOS-8. In addition, Honeywell some years acquired the XDS Sigma (formerly SDS) business, together with a little-know, but much loved by its users, system called CP-5. The group that moved over from Xerox as part of this deal convinced Honeywell that the operating system could be ported to the Honeywell processor, and have produced an interesting system called CP-6, which takes advantage of the domain features in some nice ways. For example, a process can have a debugger in one domain to debug code in other domains, putting it far ahead of almost any other system I know (including UNIX) in this area. Those interested in system design and memory management approaches ought to be aware of what is going on here. It represents a significant extension to the thinking about domains and capabilities. Unfortunately, there is little in the way of reports or other decent documentation, but perhaps some beating on Honeywell would produce something. I'm not sure that this is the right forum for this discussion. It would be nice if someone would start and manage a conference dealing with operating system and system design issues. WorkS and InfoMicro seem to have lots of people interested in these topics, but they are really focused a bit more narrowly and differently. ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.