- COFF - www.tuhs.org

three performance modeling books available again

by Charles H Sauer

In the early 1970s, when computing capabilities were tiny, tiny, tiny compared to even a cell phone today, and those resources were typically time-shared across multiple users, queueing network models became a primary tool to analyze and improve system performance. Queueing models had been studied for years before regarding communication systems and other systems, but networks of queues seemed especially apropos for understanding time-sharing systems. Computer Systems Performance Modeling, which Professor K.M. Chandy and I wrote in 1978-9, previously published by Pearson Education, Inc. is now out of print. We are making PDF copies of lightly edited versions available under a Creative Commons license. https://notes.technologists.com/notes/2020/08/25/computer-systems-performan… Ed MacNair and I published two books based on The Research Queueing Package, RESQ: Simulation of Computer Communication Systems and Elements of Practical Performance Modeling. Those books, previously published by Pearson Education, Inc. are now out of print. We are making PDF copies of lightly edited versions available under a Creative Commons license. Though we have written two prior articles about RESQ history, those did not cover subsequent development, so another recap seems appropriate now. https://notes.technologists.com/notes/2020/08/25/remembering-resq/ (Mainstream Videoconferencing: A Developer’s Guide to Distance Multimedia, which Joe Duran and I wrote from 1994-96, became available again in 2008: https://notes.technologists.com/notes/2008/02/14/mainstream-videoconferenci…) -- voice: +1.512.784.7526 e-mail: sauer(a)technologists.com fax: +1.512.346.5240 web: https://technologists.com/sauer/ Facebook/Google/Skype/Twitter: CharlesHSauer -- voice: +1.512.784.7526 e-mail: sauer(a)technologists.com fax: +1.512.346.5240 Web: https://technologists.com/sauer/ Facebook/Google/Skype/Twitter: CharlesHSauer

4 years, 3 months

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Re: [COFF] [TUHS] Monitoring by loudspeaker (was: BTL pranks)

by Michael Kjörling

(This should probably be on COFF because I don't think this has much to do with UNIX.) On 11 Jul 2020 22:22 -0400, from doug(a)cs.dartmouth.edu (Doug McIlroy): > a loudspeaker hooked to the low-order bit of the accumulator played > gentle white noise in the background. The noise would turn into a > shriek when the computer got into a tight loop, How did that work? I can see how tying the low-order bit of the accumulator to a loudspeaker would generate white noise as the computer is doing work; but I fail to see how doing so would even somewhat reliably generate a shrieking sound when the computer is in a tight loop. Please, enlighten me. :-) -- Michael Kjörling • https://michael.kjorling.se • michael(a)kjorling.se “Remember when, on the Internet, nobody cared that you were a dog?”

4 years, 4 months

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Translating Schopenhauer (was: Style command source available?)

by Greg 'groggy' Lehey

On Friday, 21 August 2020 at 17:23:11 +0200, Steffen Nurpmeso wrote: > > It was Schopenhauer who definetely said > > Neminem laede, imo omnes, quantum potes, juva! How about that, I even understood that. But for the fun of it I put it through Google Translate, and the result is worth showing: Truth injures no one, nay more, all, as much as you are able to: strengthen the faint! Of course, if you drop the !, it changes to: Truth injures no one, nay more, all, as much as you can, help the How I love syntax-independent translation! Greg -- Sent from my desktop computer. Finger grog(a)lemis.com for PGP public key. See complete headers for address and phone numbers. This message is digitally signed. If your Microsoft mail program reports problems, please read http://lemis.com/broken-MUA

4 years, 4 months

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Re: [COFF] [TUHS] Memory management in Dennis Ritchie's C Compiler

by Lars Brinkhoff

Noel Chiappa writes: > > From: Larry > > It's possible the concept existed in some other OS but I'm not > > aware of it. > > It's pretty old. Both TENEX and ITS had the ability to map file pages > into a process' address space. I have a date for when this feature was announced for ITS. The previous .CBLK UUO could not access files. RMS 09/30/73 10:13:28 JOBS! BE FIRST IN YOUR TREE TO INSERT A DISK FILE PAGE! SEE .INFO.;CORBLK ORDER FOR DETAILS. (This is now redirected to COFF.) In related news: A rather complete full dump of the MIT-AI PDP-10 from 1971 has been found. It includes full source code and documentation for the system, including ITS version 671, DDT, TECO, MIDAS, (MAC)LISP, CHESS (MacHack), MUDDLE, LOGO, MACSYMA, etc.

4 years, 4 months

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Re: [COFF] [TUHS] Memory management in Dennis Ritchie's C Compiler

by Tony Finch

--> COFF Paul Winalski <paul.winalski(a)gmail.com> wrote: mmap() / $CRETVA > The VMS image activator (runtime loader in Unix-speak) used these > primitives to load program images into virtual memory. More than one > process can map the same region of a file. This is how sharing of > read-only program segments such as .text is implemented. > > I think Burroughs OSes had this concept even before VMS. Did MULTICS work the same way? The Manchester / Ferranti Atlas had virtual memory in 1962 but I don't know how much they used it for multiprogramming (and by implication shared text segments) - it didn't do timesharing until later, but AIUI virtual memory helped it to have an exceptionally good job throughput for the time. Perhaps their motivation was more to do with having a good shared implementation of overlays and paged IO. https://en.wikipedia.org/wiki/Single-level_store Tony. -- f.anthony.n.finch <dot(a)dotat.at> http://dotat.at/ reject all prejudice and discrimination based upon race, colour, religion, age, disability, gender, or sexual orientation

4 years, 4 months

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Re: [COFF] [TUHS] A/UX [was Linux is on-topic]

by Tony Finch

moving to COFF ... Thomas Paulsen <thomas.paulsen(a)firemail.de> wrote: > >I'm sure everyone here knows this, but the Cray 1 (I think, the one > that had what looked like a circular bench seat around the bottom) was > designed like that because the clock was at the center and the clock > signal went to all the boards and was right because all the clock lines > to the boards were the same length.< > > you mean that? https://upload.wikimedia.org/wikipedia/commons/f/f7/Cray-1-deutsches-museum… I found the Cray 1M site planning reference manual very interesting - here's a summary with links to the actual documents http://www.howtospotapsychopath.com/2012/06/15/they-called-it-big-iron-for-… Tony. -- f.anthony.n.finch <dot(a)dotat.at> http://dotat.at/ Ardnamurchan Point to Cape Wrath: North or northeast 3 to 5, becoming variable 2 at times. Slight or moderate, becoming smooth or slight between Barra and Canna. Fog patches. Moderate or good, occasionally very poor.

4 years, 4 months

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Re: [COFF] [TUHS] 2bsd tarball -> pdtar, with a side of uuslave

by Nemo

(Sent to COFF as too far afield for a subthread) On 29/07/2020, John Gilmore <gnu(a)toad.com> wrote (in part): [...] > There was another chapter to the "tar wars" after UNIX and after POSIX. First, thank you for the chapter. #6-) > I put the pdtar code into the public domain, so it could be widely used. > This produced a variety of support headaches. [...] This eventually led me to > understand more of the value in using the GNU General Public License. As everyone knows, a lot of Usenet source was released into the public domain. I have been told, time and again, by IP lawyers never to release s/w unencumbered. Without an appropriate encumbrance, the author may be liable for any damage caused by said s/w -- as insane as that sounds. (I was told that there is even case law but I cannot remember what.) So your support woes could have been worse. N.

4 years, 4 months

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Cheby[cs]hev (was: Regular Expressions)

by Greg 'groggy' Lehey

[Moved to COFF] On Monday, 10 August 2020 at 9:53:14 +1000, Dave Horsfall wrote: > Interesting; I was taught it was "Chebychev", which as second ranking > doesn't even come close to "Chebyshev"... > > Possibly a cultural thing; I went to an Australian university (UNSW). I don't think so, more like coincidence. I first came across the name as "Chebyshev" at the CSIRO in Melbourne. But the difference in spelling could be attributed to the person doing the transliteration: "ch" in French corresponds in sound to "sh" in English. Greg -- Sent from my desktop computer. Finger grog(a)lemis.com for PGP public key. See complete headers for address and phone numbers. This message is digitally signed. If your Microsoft mail program reports problems, please read http://lemis.com/broken-MUA

4 years, 4 months

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Re: [COFF] BSD 211 Help forum

by jnc＠mercury.lcs.mit.edu

> From: Will Senn > So, where's a good place to pester folks for help in 211BSD, v6, v7 when > it's less along the historical interest line and more along the help I > can't get this or that working line? > ... > The question may be 211bsd, but the same type of questions often > arise for the research unixes as well. Any suggestions about where to > throw these kinds of vintage unix tech support questions? I'd just say TUHS. Your questions would me more on-topic than 1/3 of the posts. Noel

4 years, 4 months

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BSD 211 Help forum

by Will Senn

So, where's a good place to pester folks for help in 211BSD, v6, v7 when it's less along the historical interest line and more along the help I can't get this or that working line? As an example, I'm having some challenges with the networking in 211, right now. I finally (after on again off again attempts over 2 years) gotten both a vanilla 211BSD p195 system to be accessible via telnet on my local lan and am able to ping out to the internet, if I so choose, and Andru Luvisi's 211BSD p495 doing networking as well. Thanks to Andru's notes and Warner Losh's blog. In both cases, everything just "works"... well most things work :). In the 195 system, I don't seem to be able to get hostname set correctly: Assuming NETWORKING system ... sparks: bad value add net default: gateway 192.168.2.1 Whereas on the 495 system, it sets fine... Assuming NETWORKING system ... add host sparks: gateway localhost add net default: gateway 192.168.2.1 and on the 195 system, name resolution doesn't seem to function, whereas it does on the 495 system. On neither of the systems do I know how to display the routes (no netstat and route doesn't seem to have a display mode). Anyhow, I'm not really asking the question here (feel free to answer it though, if you feel so inclined), but it's the kind of question that I sit on not knowing where to ask it. I know that I often tread the knife's edge between interesting and annoying on some of my questions in TUHS and SIMH because of my lack of knowledge around these systems, but I really enjoy working in them when they work and have found that everything I learn interacting with these ancient systems significantly enhances my skills in the modern realm at least with regards to FreeBSD/Linux and Mac. Whereas, on the other hand, most of what I know about the modern systems doesn't really have an easily accessible analog in ancient unix. Take the question above, to view the route table in freebsd - it's just netstat -r, easypeasy, what the heck it might be in 211bsd is a complete mystery. Grepping the manual turns up nothing that I recognize, which is more often the case than I'd like to admit. The question may be 211bsd, but the same type of questions often arise for the research unixes as well. Any suggestions about where to throw these kinds of vintage unix tech support questions? Regards, Will -- GPG Fingerprint: 68F4 B3BD 1730 555A 4462 7D45 3EAA 5B6D A982 BAAF

4 years, 4 months

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