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Article #5Re: Mach on PC532 <-SCSI-> NeXT ? Thoughts?
From: Jonathan J. Smith
Date: Thu, 23 Jul 1992 14:44
Date: Thu, 23 Jul 1992 14:44
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In article <920723102406.10041@hfrd.dsto.gov.au> DALL@hfrd.dsto.GOV.AU writes: >pc532@bungi.com writes: > > Soon, I hope, the folks working with Mach on the PC532 > > will be able to make their work available to those without > > UNIX source licences. > >The micro kernel is free of nasty licences, the unix server isn't. > >There are a number of possibilities for a licence free server. >As I understand it, these are the CMU multi server, the GNU Hurd >and the BSD Net2 based server. The last one has the most hope >of being available early and had been done for the 386. > >It wouldn't be too big a job to do the PC532 port, but I don't >know of anyone actually doing it. > SO noone is actually already working on this project? I've been playing (yea its playing since Im not getting paid for it :), with Mach a great deal recently. Something like this would be a fun project, (so i've got a wierd sense of fun :) I'd be willing to tackle such a project, However if others are already working on it please speak up! no sense duplicating work (I'll offer to help). Also, I do not currently Own a PC532 , I am working on the solution to that however. PLEASE if someone is already working on a mach - PC532 project let me know! > > > When that happy day comes, I'd like > > to use the SCSI bus as an IPC channel between my PC532 and > > my NeXT. What do people think of this idea? > >Well, we all want to use SCSI as an IPC bus. I've got this >Sun 3/50 I want to talk to. > > > I already plan > > to write the relevant drivers, > >We are using a layered approach to the scsi drivers. There is a >machine dependent part, a machine and scsi device independent part and >a SCSI device (disk, tape, cpu, communications) dependent parts. The >support for SCSI 2 cpu and communication devices is being added by CMU >people (Alessandro Forin). > >Write the machine dependent parts and everything else should work for >free, in theory. In practice, I can't get tapes to work yet. > >Our machine dependent SCSI code still needs work. The HUT guys did the >original work and I am trying to clean up/debug it with as much time >as I can spare. Currently we don't support disconnect/reselect or >target mode. The former is pretty essential from a performance point >of view and the latter is essential for scsi2 cpu and communication >devices. > > > but what schemes are there for > > sharing compute power between dissimilar processors? > >The most promising is NORMA. I forget what it actually stands for, but >basically (from memory) it allows memory objects to be shared over a >network as if it were on the same machine. I think it even fixes up >byte order problems etc. You can, apparantly, write a process to take >advantage of multi-cpu and it works the same whether the CPU's are >tightly coupled or very loosly (NORMA) coupled. > >This sounds very nifty. The only published performance figures were >over ethernet. They got linear speed up for some sorts of problems >up to about 4 processors. With SCSI communications, the tradeoffs >would be different of course and maybe NORMA would be useful >over a wider class of problems. > >(Disclaimer: I have zero experience with NORMA, I just read a paper.) > >Ian Thanks, Jonathan Smith
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Newsgroups: comp.sys.nsc.32k Path: arc1-ca.pugleaf.net!sparky!uunet!mnemosyne.cs.du.edu!nyx!jjsmith From: jjsmith@nyx.cs.du.edu (Jonathan J. Smith) Subject: Re: Mach on PC532 <-SCSI-> NeXT ? Thoughts? Message-ID: <1992Jul23.144458.7651@mnemosyne.cs.du.edu> X-Disclaimer: Nyx is a public access Unix system run by the University of Denver for the Denver community. The University has neither control over nor responsibility for the opinions of users. Sender: usenet@mnemosyne.cs.du.edu (netnews admin account) Organization: Nyx, Public Access Unix at U. of Denver Math/CS dept. References: <920723102406.10041@hfrd.dsto.gov.au> Date: Thu, 23 Jul 92 14:44:58 GMT Lines: 76