Newsgroups: alt.folklore.computers Subject: MERT Operating System & Microkernels Organization: University of Colorado, Boulder X-Newsreader: trn 4.0-test70 (17 January 1999) From: crosby@nagina.cs.colorado.edu (Matthew Crosby) NNTP-Posting-Host: nagina.cs.colorado.edu Message-ID: <3b1801a7@cs.colorado.edu> Date: 1 Jun 2001 14:57:11 -0700 X-Trace: 1 Jun 2001 14:57:11 -0700, nagina.cs.colorado.edu Lines: 21 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!newsfeed00.sul.t-online.de!t-online.de!newscore.gigabell.net!news0.de.colt.net!colt.net!nycmny1-snf1.gtei.net!nycmny1-snh1.gtei.net!denver-snf1.gtei.net!news.gtei.net!coop.net!cs.colorado.edu!csnews!nagina.cs.colorado.edu!crosby Xref: chonsp.franklin.ch alt.folklore.computers:82657 One of my co-workers (of ex USL extraction) brought in editions of the Bell System Technical Journal for July/Aug 1978 and 1984 that he'd had sitting around; these are the two editions that were dedicated to Unix (were there others?) (Interstingly, the 78 one has "S Johnson" on the inside cover. I wonder if that's _the_ S Johnson?) Anyway, there is a paper on the MERT Operating System in the 78 one which was interesting reading. I'd never heard of MERT before. It looks like a micro-kernelish RT OS that can run Unix as a server on top, which is interesting--forshadowing Mach and the like. Was this just a Bell Labs internal research thing? Am I wrong in characterising it as having micro-kernel characteristics? (And what would be the earliest micro kernel anyway?) Is there somewhere I can see more information on this? -- Matthew Crosby crosby@cs.colorado.edu Disclaimer: It was in another country, and besides, the wench is dead. ###### Sender: lynn@LYNNPC Newsgroups: alt.folklore.computers Subject: Re: MERT Operating System & Microkernels References: <3b1801a7@cs.colorado.edu> Reply-To: Anne & Lynn Wheeler From: Anne & Lynn Wheeler Message-ID: Organization: Wheeler&Wheeler Lines: 63 User-Agent: Gnus/5.0808 (Gnus v5.8.8) Emacs/20.6 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 01 Jun 2001 21:22:20 GMT NNTP-Posting-Host: 199.174.230.99 X-Complaints-To: abuse@earthlink.net X-Trace: newsread2.prod.itd.earthlink.net 991430540 199.174.230.99 (Fri, 01 Jun 2001 14:22:20 PDT) NNTP-Posting-Date: Fri, 01 Jun 2001 14:22:20 PDT X-Received-Date: Fri, 01 Jun 2001 14:20:21 PDT (newsmaster1.prod.itd.earthlink.net) Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!enews.sgi.com!news-peer-west.sprintlink.net!news.sprintlink.net!newsfeed.direct.ca!look.ca!newsfeed1.earthlink.net!newsfeed.earthlink.net!newsmaster1.prod.itd.earthlink.net!newsread2.prod.itd.earthlink.net.POSTED!not-for-mail Xref: chonsp.franklin.ch alt.folklore.computers:82685 crosby@nagina.cs.colorado.edu (Matthew Crosby) writes: > Anyway, there is a paper on the MERT Operating System in the 78 one > which was interesting reading. I'd never heard of MERT before. It > looks like a micro-kernelish RT OS that can run Unix as a server on > top, which is interesting--forshadowing Mach and the like. > > Was this just a Bell Labs internal research thing? Am I wrong in > characterising it as having micro-kernel characteristics? (And what would > be the earliest micro kernel anyway?) Is there somewhere I can see more > information on this? one would be tempted to claim that cp/67 was one of the original micro-kernels that allowed other stuff to be run "on top". the current incarnation as vm???? being able to run 40,000+ some odd copies of Linux is hardly a micro-kernel anymore. however, the flavor that morphed into the microcode of the current machines that provides the LPAR support ... aka large number of current mainframes run the operating systems in LPARs ... one additional level removed from the "real" hardware. note also ... unix running on a tss/370 kernel saw large deployment inside at&t and there have been numerous instances of unix (from a number of different vendors) deployed on various VM-based platforms over the years. other microkernel candidates would be pieces of RSCS/VNET that managed networking for cp/67 & VM/370 (and the internal network). I remember hearing somebody claim (sometime within the past 10 years or so) that one of the current popular real-time systems ... for at least one of the core components (written in C) reads line-for-line the same as one of the core components from RSCS (written in 360 assembler) except for the differences in the language ... the logic is the same and the comments track statement for statement down to the same mis-spellings. http://www.garlic.com/~lynn/98.html#45 Why can't more CPUs virtualize themselves? http://www.garlic.com/~lynn/98.html#57 Reliability and SMPs http://www.garlic.com/~lynn/99.html#191 Merced Processor Support at it again . . . http://www.garlic.com/~lynn/2000.html#8 Computer of the century http://www.garlic.com/~lynn/2000.html#63 Mainframe operating systems http://www.garlic.com/~lynn/2000.html#86 Ux's good points. http://www.garlic.com/~lynn/2000b.html#43 Migrating pages from a paging device (was Re: removal of paging device) http://www.garlic.com/~lynn/2000b.html#50 VM (not VMS or Virtual Machine, the IBM sort) http://www.garlic.com/~lynn/2000b.html#51 VM (not VMS or Virtual Machine, the IBM sort) http://www.garlic.com/~lynn/2000b.html#52 VM (not VMS or Virtual Machine, the IBM sort) http://www.garlic.com/~lynn/2000b.html#61 VM (not VMS or Virtual Machine, the IBM sort) http://www.garlic.com/~lynn/2000b.html#62 VM (not VMS or Virtual Machine, the IBM sort) http://www.garlic.com/~lynn/2000c.html#8 IBM Linux http://www.garlic.com/~lynn/2000c.html#50 Does the word "mainframe" still have a meaning? http://www.garlic.com/~lynn/2000c.html#68 Does the word "mainframe" still have a meaning? http://www.garlic.com/~lynn/2000c.html#76 Is a VAX a mainframe? http://www.garlic.com/~lynn/2000d.html#72 When the Internet went private http://www.garlic.com/~lynn/2000f.html#78 TSS ancient history, was X86 ultimate CISC? designs) http://www.garlic.com/~lynn/2000g.html#3 virtualizable 360, was TSS ancient history http://www.garlic.com/~lynn/2001b.html#41 First OS? http://www.garlic.com/~lynn/2001b.html#72 Z/90, S/390, 370/ESA (slightly off topic) http://www.garlic.com/~lynn/2001e.html#5 SIMTICS http://www.garlic.com/~lynn/2001e.html#12 Blame it all on Microsoft http://www.garlic.com/~lynn/2001e.html#61 Estimate JCL overhead http://www.garlic.com/~lynn/2001f.html#17 Accounting systems ... still in use? (Do we still share?) -- Anne & Lynn Wheeler | lynn@garlic.com - http://www.garlic.com/~lynn/ ###### From: Dennis Ritchie Newsgroups: alt.folklore.computers Subject: Re: MERT Operating System & Microkernels Date: Sat, 02 Jun 2001 04:24:25 +0000 Organization: Bell Labs / Lucent Technologies Lines: 30 Message-ID: <3B186A79.C7620091@bell-labs.com> References: <3b1801a7@cs.colorado.edu> NNTP-Posting-Host: 135.104.65.78 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 4.61 [en] (WinNT; U) X-Accept-Language: en Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!news.maxwell.syr.edu!newsfeed.skycache.com!Cidera!portc01.blue.aol.com!wn3feed!worldnet.att.net!207.24.196.41!nntphub.cb.lucent.com!news Xref: chonsp.franklin.ch alt.folklore.computers:82666 Matthew Crosby wrote: > > One of my co-workers (of ex USL extraction) brought in editions of > the Bell System Technical Journal for July/Aug 1978 and 1984 that he'd had > sitting around; these are the two editions that were dedicated to Unix > (were there others?) > > (Interstingly, the 78 one has "S Johnson" on the inside cover. I wonder if > that's _the_ S Johnson?) > > Anyway, there is a paper on the MERT Operating System in the 78 one > which was interesting reading. I'd never heard of MERT before. It > looks like a micro-kernelish RT OS that can run Unix as a server on > top, which is interesting--forshadowing Mach and the like. > > Was this just a Bell Labs internal research thing? Am I wrong in > characterising it as having micro-kernel characteristics? (And what would > be the earliest micro kernel anyway?) Is there somewhere I can see more > information on this? MERT was a research system (yes, microkernelish). It might have been made available to some extent under a Unix-like license. It evolved into DMERT (D for Duplex), the OS used for the 3B20D processor that ran/runs 5ESS telephone central offices. I suspect that DMERT is still involved in switching the bulk of CO lines in the US today, although the trend in recent years has been to distribute processing outboard of the central processors. Dennis ###### From: dscheidt@tumbolia.com (David Scheidt) Newsgroups: alt.folklore.computers Subject: Re: MERT Operating System & Microkernels Date: 2 Jun 2001 04:37:50 GMT Lines: 23 Sender: David Scheidt Message-ID: <9f9qiu$k5d$1@bob.news.rcn.net> References: <3b1801a7@cs.colorado.edu> <3B186A79.C7620091@bell-labs.com> X-Trace: UmFuZG9tSVaOTd8ELoylDGNRmtSLuSUj0J6S59Ry3NLDMJ//C3iKagl8w4di4K3P X-Complaints-To: abuse@rcn.com NNTP-Posting-Date: 2 Jun 2001 04:37:50 GMT User-Agent: tin/1.4.4-20000803 ("Vet for the Insane") (UNIX) (FreeBSD/4.2-STABLE (i386)) Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!news.maxwell.syr.edu!newsfeed.skycache.com!Cidera!netnews.com!feed2.news.rcn.net!feed1.news.rcn.net!rcn!not-for-mail Xref: chonsp.franklin.ch alt.folklore.computers:82680 Dennis Ritchie wrote: : MERT was a research system (yes, microkernelish). It might have been : made available to some extent under a Unix-like license. It evolved : into DMERT (D for Duplex), the OS used for the 3B20D processor that : ran/runs 5ESS telephone central offices. I suspect that DMERT is : still involved in switching the bulk of CO lines in the US today, : although the trend in recent years has been to distribute processing : outboard of the central processors. All of the Lucent documentation on the 5ESS 3B20 (and 3B21, which is what newer 5E's have) I've seen calls the OS "Unix RTR". RTR stands for "Real-Time Reliable". I've thought that it should be reird, truely-reird, since it's weird. I have no idea what the relationship between RTR and DMERT is. They may have just changed the name. David -- dscheidt@tumbolia.com Bipedalism is only a fad. ###### Sender: eric@ruckus.brouhaha.com From: Eric Smith Newsgroups: alt.folklore.computers Subject: Re: MERT Operating System & Microkernels References: <3b1801a7@cs.colorado.edu> X-Disclaimer: Everything I write is false. Organization: Eric Conspiracy Secret Labs X-Eric-Conspiracy: There is no conspiracy. Date: 02 Jun 2001 01:12:14 -0700 Message-ID: Lines: 5 User-Agent: Gnus/5.0807 (Gnus v5.8.7) Emacs/20.7 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii NNTP-Posting-Host: ruckus.brouhaha.com X-Trace: 2 Jun 2001 01:29:21 -0700, ruckus.brouhaha.com Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!news-fra1.dfn.de!news-koe1.dfn.de!news-was.dfn.de!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!out.nntp.be!propagator-dallas!news-in-dallas.newsfeeds.com!in.nntp.be!news.kjsl.com!news.spies.com!ruckus.brouhaha.com Xref: chonsp.franklin.ch alt.folklore.computers:82725 crosby@nagina.cs.colorado.edu (Matthew Crosby) writes about MERT: > Was this just a Bell Labs internal research thing? No, it shipped to customers. Bonus points if you know what AT&T product(s). ###### From: jra@dorothy.msas.net (Jay R. Ashworth) Newsgroups: alt.folklore.computers Subject: Re: MERT Operating System & Microkernels References: <3b1801a7@cs.colorado.edu> <3B186A79.C7620091@bell-labs.com> <9f9qiu$k5d$1@bob.news.rcn.net> Reply-To: jra@baylink.com Message-ID: User-Agent: slrn/0.9.6.2 (Linux) Lines: 26 Date: Sun, 03 Jun 2001 04:29:55 GMT NNTP-Posting-Host: 65.32.177.248 X-Complaints-To: abuse@rr.com X-Trace: typhoon.tampabay.rr.com 991542595 65.32.177.248 (Sun, 03 Jun 2001 00:29:55 EDT) NNTP-Posting-Date: Sun, 03 Jun 2001 00:29:55 EDT Organization: RoadRunner - TampaBay Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!news-fra1.dfn.de!fu-berlin.de!news.stealth.net!news-east.rr.com!news.rr.com!cyclone.tampabay.rr.com!news-post.tampabay.rr.com!typhoon.tampabay.rr.com.POSTED!not-for-mail Xref: chonsp.franklin.ch alt.folklore.computers:82813 *Right* in the middle of the appendectomy, David Scheidt turned to Hawkeye and me and said: > Dennis Ritchie wrote: > : MERT was a research system (yes, microkernelish). It might have been > : made available to some extent under a Unix-like license. It evolved > : into DMERT (D for Duplex), the OS used for the 3B20D processor that > : ran/runs 5ESS telephone central offices. I suspect that DMERT is > : still involved in switching the bulk of CO lines in the US today, > : although the trend in recent years has been to distribute processing > : outboard of the central processors. > > All of the Lucent documentation on the 5ESS 3B20 (and 3B21, which is what > newer 5E's have) Note that that's, rather specifically, the 3B20*D*; there was a single processor version to, AIUI. Largest one I ever got next to was a 3b5. Cheers, -- jra '...!jc3b21!jra' a -- Jay R. Ashworth jra@baylink.com Member of the Technical Staff Baylink The Suncoast Freenet The Things I Think Tampa Bay, Florida http://baylink.pitas.com +1 727 804 5015 OS X: Because making Unix user-friendly was easier than debugging Windows ###### From: dscheidt@tumbolia.com (David Scheidt) Newsgroups: alt.folklore.computers Subject: Re: MERT Operating System & Microkernels Date: 3 Jun 2001 08:42:55 GMT Lines: 74 Sender: David Scheidt Message-ID: <9fctaf$ljc$1@bob.news.rcn.net> References: <3b1801a7@cs.colorado.edu> <3B186A79.C7620091@bell-labs.com> <9f9qiu$k5d$1@bob.news.rcn.net> X-Trace: UmFuZG9tSVYU2atAlK327EKu6T4TQYc5TG/yLAxJd0MHXxr1QoByaG70lOYL6LzF X-Complaints-To: abuse@rcn.com NNTP-Posting-Date: 3 Jun 2001 08:42:55 GMT User-Agent: tin/1.4.4-20000803 ("Vet for the Insane") (UNIX) (FreeBSD/4.2-STABLE (i386)) Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!news.maxwell.syr.edu!feed2.news.rcn.net!feed1.news.rcn.net!rcn!not-for-mail Xref: chonsp.franklin.ch alt.folklore.computers:82775 Jay R. Ashworth wrote: : *Right* in the middle of the appendectomy, David Scheidt turned : to Hawkeye and me and said: :> Dennis Ritchie wrote: :> : MERT was a research system (yes, microkernelish). It might have been :> : made available to some extent under a Unix-like license. It evolved :> : into DMERT (D for Duplex), the OS used for the 3B20D processor that :> : ran/runs 5ESS telephone central offices. I suspect that DMERT is :> : still involved in switching the bulk of CO lines in the US today, :> : although the trend in recent years has been to distribute processing :> : outboard of the central processors. :> :> All of the Lucent documentation on the 5ESS 3B20 (and 3B21, which is what :> newer 5E's have) : Note that that's, rather specifically, the 3B20*D*; there was a single : processor version to, AIUI. Largest one I ever got next to was a 3b5. Right. The 3B20D/3B21D are the duplex versions, while the the 3B20S/3B21S are simplex. As I understand it, the S models are the same as the D versions, minus the duplex bits. The 3B20/21 have some very nice fault detection hardware. On a fault, the standby side can be brought on line instantly (in the middle of an instruction. I think the instruction is restarted. There has to be someone here who knows more about these things than I do!). The S versions have the same detection hardware, but since they don't have a spare processor waiting for a failure, they just shut down. I'm pretty sure you can build a 5ESS using a 3B2?S as the AM[1], which you wouldn't do if you were trying to meet the reliabilty standards of a comerecial switch (on the order of 10 hours downtime in a couple decades), but for a lab/test environment would be cheaper. [1] AM is the "Administrative Module". It doesn't do actual call processing, but does administrative functions like Operations, Administration and Maintance (OA&M), and provides the interface for Operation Support Systems (OSS, which are what I've been involved with, things like billing and provisioning). The 5E, and most modern switches, are distributed processing systems. The 5ESS looks something like this (I'm horrible at ASCII art, sorry. ) links | | | DLN to OSS| | | link to and | | | CNI and IN TTYs | | | ------------- __________ ______ | | | | ------- | SM | | AM |-----| CM | ------ | (3B20D) | | | (up to 192 SMs) | | | | ----- |-----------| |________| --------| SM | ---... Lines/trunks ------ There's a whole bunch of simplification going on here, in the form of missing subsystems -- The AM has the normal sort of disk and tape systems attached, and terminals and remote systems are hung off an I/O processor. The CM is the "Communications Module". It handles inter-component communications. It's got several different busses that handle this. There's a time-multiplexed bus for voice and data paths between SMs, as well as several message busses. What's here depends greatly on what version of the switch it is, and the software levels. The SMs are "Switch Modules". They do most of the call processing. They can be configured to terminate subscriber lines, inter-switch trunks, or wireless cell sites. There could be up to 192 SMs attached to a switch, each terminating several thousand lines or trunks. The current SM, the SM-2000, is limited to only (24? 32? I forget) per switch. They are of much higher capacity than previous versions, capable of terminating 30,000 lines each. SMs are built around Motorola 680x0 micro-processors; I think the SM-2000 uses a 68060. -- dscheidt@tumbolia.com Bipedalism is only a fad.