TUHS February 2020

tuhs@tuhs.org

77 participants
39 discussions

Re: [TUHS] Distributed systems, was: On the origins of Linux - "an academic question"

by Andrew Warkentin

On 1/17/20, Brantley Coile <brantley(a)coraid.com> wrote: > what he said. > >> On Jan 17, 2020, at 6:20 PM, Rob Pike <robpike(a)gmail.com> wrote: >> >> Plan 9 is not a "single-system-image cluster". >> >> -rob >> > > I guess SSI isn't the right term for Plan 9 clustering since not everything is shared, although I would still say it has some aspects of SSI. I was talking about systems that try to make a cluster look like a single machine in some way even if they don't share everything (I'm not sure if there's a better term for such systems besides the rather vague "distributed" which could mean anything from full SSI to systems that allow transparent access to services/devices on other machines without trying to make a cluster look like a single system).

5 years, 1 month

Idea: a regular video chat

by Warren Toomey

[x-posting to COFF] Idea: anybody interested in a regular video chat? I was thinking of one that progresses(*) through three different timezones (Asia/Aus/NZ, then the Americas, then Europe/Africa) so that everybody should be able to get to two of the three timezones. (* like a progressive dinner) 30-60 minutes each one, general old computing. Perhaps a guest speaker now and then with a short presentation. Perhaps a theme now and then. Perhaps just chew the fat, shoot the breeze as well. Platform: Zoom or I'd be happy to set up a private Jitsi instance. Something else? How often: perhaps weekly or fortnightly through the three timezones, so it would cycle back every three or six weeks. Comments, suggestions?! Cheers, Warren

5 years, 1 month

Re: [TUHS] UNIBUS issues (Was: Spacewar at Bell Labs)

by jnc＠mercury.lcs.mit.edu

> From: Dave Horsfall <dave(a)horsfall.org> > [ Getting into COFF territory, I think ] I'm sending this reply to TUHS since the message I'm replying to has some errors, and I'd like for the corrections to be in the record close by. > On Thu, 30 Jan 2020, Clem Cole wrote: >> They way they tried to control it was to license the bus interface chips >> (made privately by Western Digital for them IIRC but were not available >> on the open market). Although DEC did have some custom chips for QBUS interfacing, they didn't always use them (below). And for the UNIBUS, the chips were always, AFAIK, open market (and the earliest ones may have predated the UNIBUS). E.g. the M105 Address Selector, a single-width FLIP CHIP, used in the earliest PDP-11's when devices such as the RK11-C, RP11 and TM11 were made out of a mass of small FLIP CHIPS, used SP380A's for its bus receivers and 8881's for transmitters. On the QBUS, the KDF11-A and KDJ11-A CPU cards used AMD 2908's as bus transceivers, even though DEC had its own custom chips. The KDF11-A also used DS8640's and DS8641's (transmitters and receivers), and also an 8881! (The UNIBUS and QBUS were effectively identical at the analog level, which is why a chip that historical was still in use.) >> If I recall it was the analog characteristics that were tricky with >> something like the BUS acquisition for DMA and Memory timing, but I >> admit I've forgotten the details. One _possibility_ for what he was talking about was that it took DEC a while to get a race/metastability issue with daisy-chained bus grant lines under control. (The issue is explained in some detail here: https://gunkies.org/wiki/Bus_Arbitration_on_the_Unibus_and_QBUS and linked pages.) This can been seen in the myriad of etch revisions for the M782 and related 'bus grant' FLIP CHIPs: https://gunkies.org/wiki/M782_Interrupt_Control By comparison, the M105 only had 3 through it's whole life! It wasn't until the M7821 etch D revision, which came out in 1977, almost a decade after the first PDP-11's appeared, that they seemed to have absorbed that the only 'solution' to the race/metastability issue involved adding delays. In all fairness, the entire field didn't really appreciate the metastability issue until the LINC guys at WUSTL did a big investigation of it, and then started a big campaign to educate everyone about it - it wasn't DEC being particularly clueless. > Hey, if the DEC marketoids didn't want 3rd-party UNIBUS implementations > then why was it published? Well, exactly - but it's useful to remember the differening situation for DEC from 1970 (first PDP-11's) and later. In 1970 DEC was mostly selling to scientists/engineers, who wanted to hook up to some lab equipment they'd built, and OEM's, who often wanted to use a mini to control some value-added gear of their own devising. An open bus was really necessary for those markets. Which is why the 1970 PDP-11/20 manual goes into a lot of detail on how to interface to the PDP-11's UNIBUS. Later, of course, they were in a different business model. Noel

5 years, 1 month

Re: [TUHS] Screen editors

by Jose R. Valverde

Talking of editors... Once I learned Wordstar in old CP/M (before that it was mostly line editing), and then soon, other editors that supported the Wordstar key combinations, I got hooked on those. Joe is, to date, one of my favorites. On ancient UNIX, my editor of choice was 's' from Software Tools, its main advantage being that it didn't require curses. Then we got VMS and 'eve' and that took over for a while (though I never took advantage of all its power), mostly until I ported 's' and 'joe'. Then came X, and when nedit was released, I was hooked on it. It has been for decades almost the only one that could do block selection 'a la' RAND editor. I have been struggling to continue using it despite it lack of support for UTF, trying various projects spun off nedit, until I recently discovered xnedit, which is an update available on GitHub and is again all I need, with support for UTF8, some minor UI improvements and support for modern fonts. Now, I still use 's' for ancient Unix emulators, 'joe' for the command line and 'xnedit' for X. j -- Scientific Computing Service Solving all your computer needs for Scientific Research. http://bioportal.cnb.csic.es

5 years, 1 month

Presotto paper

by Paul Ruizendaal

On the Nokia / Bell labs site I came across this publication: https://www.bell-labs.com/our-research/publications/234131/ <https://www.bell-labs.com/our-research/publications/234131/> Presotto D.: TCP/IP and Datakit - Two Views of Networking I’m not having much luck with finding out more about it. Does anybody recall this paper and where/when it might have been published?

5 years, 1 month

Atari System V media and books?

by Chris Hanson

I’ve seen the archives of Atari System V Release 4 for the TT030, and the scanned user and developer manuals. Has anything else been preserved, e.g. the installation tapes and any other manuals? Is there even a full accounting of what was in the box and what shipped afterwards (patches etc.)? -- Chris

5 years, 1 month

Re: [TUHS] System Call History

by Doug McIlroy

> Does anybody have or know of a list of system calls that describes > when and what version of UNIX (and descendents) they were added? Hardly a week goes by in which I don't refer to the attached condensed listing of all the man pages in v1-v9, taken from my "Research Unix Reader". It casts a much narrower net than Diomedes Spinelli's repository. but it takes no clicking to look thing up--just a quick grep. Doug

5 years, 1 month

System Call History

by Jon Steinhart

Does anybody have or know of a list of system calls that describes when and what version of UNIX (and descendents) they were added? Thanks, Jon

5 years, 1 month

Re: [TUHS] Spacewar at Bell Labs [ really paper tape readers and tangentially related things ]

by Dave Horsfall

[ Getting into COFF territory, I think ] On Thu, 30 Jan 2020, Clem Cole wrote: > BTW: Dave story is fun, but I think a tad apocryphal. He's right that > DEC marketing was not happy about people using it, but it was well > spec'ed if you had CPU schematics. They way they tried to control it > was to license the bus interface chips (made privately by Western > Digital for them IIRC but were not available on the open market). IIRC > if you did not use DEC's chips, you could have issues if you >>similar<< > function chips from National Semi. I remember Ken O'Munhundro giving a > talk at a USENIX (while he was CEO of Able) talking about 'be careful > with foreign UNIBUS implementations.' If I recall it was the analog > characteristics that were tricky with something like the BUS acquisition > for DMA and Memory timing, but I admit I've forgotten the details. Ah; the chips could explain it. I can't remember where I heard the story, but it was likely in ";login:" or some place. Hey, if the DEC marketoids didn't want 3rd-party UNIBUS implementations then why was it published? > I think you are confusing VAX's SBI with UNIBUS. With the Vax, unlike > PDP-11, the systems did not come with complete schematics for all > boards. So to design for the SBI you had to reverse engineer the CPU > and Memory boards. DEC having successfully won the CalData suit, went > after Systems Industries who was the first to build SBI controllers. > DEC lost, but the truth was that because they had work had been reverse > engineering, SI was close but not 100% right and they had a number of > issues when the boards first hit the street, particularly with UNIX > which did a better job of overlapped I/O than VMS did. At UCB we had a > logic analyzer in one of the 780s at all times, and the phone number of > the SI engineers. We eventually helped them put out a couple ECO's > that make the original boards work in practice much better. No; it was definitely UNIBUS (I wasn't aware of the SBI at the time). As for overlapped seeks, when they were implemented in Unix it broke the RK-11 controller, and DEC pointed the finger at Unix (of course) since their own gear worked. To cut a long story short, they were forced to use some fancy diagnostic (DECEX?) which hammered everything at the same time, and the problem showed up. Turned out that their simpler diagnostics did not test for overlapped seeks, because they knew that it didn't work; out same the FE to modify the controller... > BTW: My friend Dave Cane lead the BI at DEC after finishing up the > VAX/750 project (he had designed the SBI for 780 before that). In > fact, the BI was >>supposed<< to be 'open' like Multibus and VME and all > chips were supposed to be from the merchant market. But at the last > minute, DEC marketing refused and locked down the specs/stopped shipping > schematics with the new systems destined to use BI. Dave was so pissed, > he left DEC to found Masscomp and design the MC500 (using the > Multibus). Yet another reason why DEC went under, I guess... -- Dave

5 years, 1 month

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TUHS February 2020