TUHS January 2019

tuhs@tuhs.org

67 participants
52 discussions

by Paul Ruizendaal

Clem, Ron, Thanks for the explanations! Some comments below. >> 1. First of all: I understand that early Unix version numbers and dates >> mostly refer to the manual editions, and that core users had more >> frequent snapshots of a constantly evolving code base. > > Eh? They primarily refer to the distributions (Research V6, V7, PWB, the > various BSD tapes). > I'm not sure what "core users" are referring to. Most of us had many > versions as we hacked and merged the stock releasesx. I was too brief. I was referring just to the pre-V7 versions, and I had the implicit assumption that alarm() originated at the labs. My understanding was that the labels 5th, 6th and 7th edition had little meaning inside the labs, as there just was a continuously developing code base. Maybe this is a mis-understanding. > "alarm was introduced as part of Unix/TS" "PWB [..] had both sleep() and alarm() as system calls" Thanks for those pointers! I'm not sure I fully grasp the lineage of Unix/TS and PWB, but the TUHS wiki has a page about it: https://wiki.tuhs.org/doku.php?id=misc:snippets:mert1 From that, and from the TUHS Unix Tree web page I get that PWB1.0 from mid 1977 was probably the root source of alarm() for people outside AT&T. As PWB apparently got started much before that, it is possible that alarm() goes back much further as well. > A bigger networking issue was select() (or the like). It used to be an > interesting kludge of running two processes inorder to do simoultaneous > read/write before that. Yes: the NCP Unix team (Grossman/Holmgren/Bunch) also mentioned that as the big issue/annoyance that they ran into in 1975. As discussed in this list before, 3 years elapsed before Jack Haverty came up with await() for V6. I was told that there was a lot of discussion in the 4.1x/4.2 BSD steering group in 1981/2 whether this functionality should be stateful (like await) or stateless (like select). Looking at the implementations for both, I can see why stateless carried the day. > Right and select(2) was created by Sam and wnj during the 4.2 development. I've forgotten which sub-version (it was in 4.1c, but it might have been in b or a before that). There was a lot of arguing at the time about it's need; the multiple process solution was considered more 'Unix-like.' That is an interesting point, and it got me wondering about another related feature that could have been in Unix in the 1975-1980 time frame, being both useful and practical even on a 11/40 class machine, but for some reason wasn't: It would not seem terribly complex to add non-blocking i/o capability to V6. It could have been implemented as a TTY flag and it is not a big conceptual leap from EINTR to EAGAIN. Adding a 'capacity' field to the sgtty interface would not have been a big leap either. This would have allowed user processes to scan a number of tty lines e.g. once a second in a loop and do processing as needed. In NCP Unix this would not have been hard to extend to network pipes. The NCP Unix / Arpanet crowd certainly had a need for it, it would have been very useful for Spider/Datakit connections and probably for uucp as well. And from there it is not a million miles to replace the timed user loop with something like select(). Yet non-blocking I/O and select() only appear in 1982. Maybe in the 1975-1980 time frame this was not felt to be 'how Unix does it'?

5 years, 3 months

AT&T / Teletype DMD 5620 Emulator

by Seth J. Morabito

Hello folks, I realized I should mention this here on TUHS, since it is likely of interest to at least some of you! I recently wrote a DMD 5620 emulator, currently available on Linux and Macintosh, with Windows support coming soon. Here's a brief demo of the Mac version: https://www.youtube.com/watch?v=tcSWqBmAMeY I wrote it because DMD 5620s are becoming incredibly rare, and showing them off in person is quite difficult nowadays. This emulator is using ROM version 2.0 (8;7;5) dumped from my personal 5620. If anyone out there has a DMD 5620 with an older ROM, I would be incredibly grateful if you could dump the ROMs. I'd like to find versions of 1.x (8;7;3 or earlier); so far I've had no luck. The main reason I'm interested in older ROMs, besides pure preservation reasons, is that the 'mux' and 'muxterm' system on Research UNIX V8/V9 is hard-coded for the 1.1 ROMs. It doesn't work with the emulator without significant tweaking of the source. It DOES work perfectly well with the DMD Core Utilities package for the AT&T 3B2, however. All the best! -Seth -- Seth Morabito Poulsbo, WA, USA web(a)loomcom.com

5 years, 3 months

Re: [TUHS] Happy birthday, C.A.R. Hoare!

by Paul McJones

In the June 1966 CACM [1], Wirth and Hoare published "A contribution to the development of ALGOL”, which describes a language very similar to Algol W. In Wirth’s Turing Award lecture (published in the Feb 1985 CACM [2]) "From programming language design to computer construction”, he noted: “The Working Group assumed the task of proposing a successor and soon split into two camps. On one side were the ambitious who wanted to erect another milestone in language design, and, on the other, those who felt that time was pressing and that an adequately extended ALGOL 60 would be a productive endeavor. I belonged to this second party and submitted a proposal that lost the election. Thereafter, the proposal was improved with contributions from Tony Hoare (a member of the same group) and implemented on Stanford University's first IBM 360. The language later became known as ALGOL W and was used in several universities for teaching purposes.” In particular, Hoare’s work on “Record Handling” (see [3]) had a strong impact on Algol W and Wirth’s later languages. [1] http://doi.acm.org/10.1145/365696.3657022 [2] http://doi.acm.org/10.1145/2786.2789 [3] http://www.softwarepreservation.org/projects/ALGOL/standards/. > On Jan 10, 2019, at 7:06 PM, clemc(a)ccc.com wrote: > > From: Clem cole <clemc(a)ccc.com <mailto:clemc@ccc.com>> > To: Dave Horsfall <dave(a)horsfall.org <mailto:dave@horsfall.org>> > Cc: The Eunuchs Hysterical Society <tuhs(a)tuhs.org <mailto:tuhs@tuhs.org>> > > Dave. The w in Algolw was Wirth. He was at Stanford at the time. It was written in PL/360 btw. The sources are googlable. FWIW Pascal was done a couple of years later with lessons learned from Algolw and reaction to Algol68. > > Sent from my PDP-7 Running UNIX V0 expect things to be almost but not quite. > >> On Jan 10, 2019, at 6:52 PM, Dave Horsfall <dave(a)horsfall.org <mailto:dave@horsfall.org>> wrote: >> >> [Not sure whether this is more appropriate for COFF instead, so it's here; advice (apart from STFU) gratefully accepted.) >> >> Sir Charles Antony Richard Hoare FRS FREng was born on this day in 1934; a computer pioneer (one of the greats) he gave us things like the quicksort algorithm (which became qsort() in Unix) and ALGOLW (a neat language). >> >> -- Dave >

5 years, 3 months

Happy birthday, C.A.R. Hoare!

by Dave Horsfall

[Not sure whether this is more appropriate for COFF instead, so it's here; advice (apart from STFU) gratefully accepted.) Sir Charles Antony Richard Hoare FRS FREng was born on this day in 1934; a computer pioneer (one of the greats) he gave us things like the quicksort algorithm (which became qsort() in Unix) and ALGOLW (a neat language). -- Dave

5 years, 3 months

Origin of the name 'strategy'

by Warner Losh

So what's the origin of the name 'strategy' for the I/O routine in Unix that drivers provide? Everything I've found in the early papers just says that's what the routine is called. Is there a story behind why it was chosen? My own theory is that it's in the sense of 'coping strategy' when the driver needs to service more I/O for the upper layers, but that's just a WAG. Warner

5 years, 3 months

Re: [TUHS] Origin of the name 'strategy'

by Dave Horsfall

On Tue, 8 Jan 2019, Warner Losh wrote: > The name seems obvious because I've seen it for the last 30 years. But > I've not seen it used elsewhere, nor have I seen it documented except in > relationship to Unix. It could have been called blkio or bufio or bio or > even just work or morework and still been as meaningful. VMS uses the > FDT table to process the IRPs sent down. RT-11 has a series of entry > points that have boring names. Other systems have a start routine > (though more often that is a common routine used by both the queue me > and isr functions). There is a wide diversity here... I must admit that this is an interesting thread, just as long as it wasn't called XXoptimize() unless you wanted a backlash from British English speakers :-) In hindsight I suppose that XXstrategy() is obvious, but back then, as you ask? Dunno, but Ken might (if he's reading this thread). One of my favo[u]rites is sched(); some pronounce it as "shed" and others as "sked". Another American/British thing, I think... Wasn't it Mark Twain who said "Two nations divided by a common language"? I no longer have my Lions books on me, sadly enough (lost in a house move) but there certainly were some peculiar names in the kernel... ObGripe: Could anyone replying to the digest version please take the trouble to update the Subject: line accordingly? I've now put the original back as a courtesy to others, but I shouldn't have to; it's as bad as top-posting. -- Dave

5 years, 3 months

Re: [TUHS] TUHS Digest, Vol 38, Issue 10

by Steve Simon

re disk stagey i understood that this implemented the elevator algorithm, and possible rotational latency compensation. re non-gcc compilers there was a time in the early 2000s when some people tried release plan9’s (ken’s) c compiler for use in BSD bsd, sadly (for plan9) this didn't happen. pcc was reanimated instead.

5 years, 3 months

National Inventors Hall of Fame honors creators of Unix

by Warren Toomey

https://www.engadget.com/2019/01/08/national-inventors-hall-of-fame-class-o… The National Inventors Hall of Fame (NIHF) joined Engadget on stage today at CES to announce its 2019 class of inductees. [ including ] ... Dennis Ritchie (Posthumous) and Ken Thompson: UNIX Operating System ------------------------------------------------------------------- Thompson and Ritchie's creation of the UNIX operating system and the C programming language were pivotal developments in the progress of computer science. Today, 50 years after its beginnings, UNIX and UNIX-like systems continue to run machinery from supercomputers to smartphones. The UNIX operating system remains the basis of much of the world's computing infrastructure, and C language -- written to simplify the development of UNIX -- is one of the most widely used languages today. Cheers, Warren

5 years, 3 months

QED archive now available

by Arnold Robbins

Hi All. Back in October I started a discussion about QED sources. A number of people were kind enough to send me tarballs and zip files as well as pointers to other archives. I have finally cobbled it all together and made it available on GitHub: https://github.com/arnoldrobbins/qed-archive I have tried to acknowledge everyone who contributed. Thanks again to all who did send me stuff and email me. Enjoy, Arnold

5 years, 3 months

off topic - capatob - saratov2 computer Russsian pdp8? HELP

by Dr Iain Maoileoin

Off topic, but looking for help and wisdom. If you visit https://www.scotnet.co.uk/iain/ <https://www.scotnet.co.uk/iain/>saratov you will see some photos of work that I have started on the front panel of a Capatob2. I plan to get the switches and lights running on a blinkenbone board with a PDP8 emulation behind it. (I already have an PDP11/70 front-panel running on the same infrastructure) I have been struggling for over a year to get much info about this saratov computer (circuit diagrams etc). So I have started the reverse engineering on the panel. Does anybody know anything about this computer? online or offline it would be much appreciated. Iain

5 years, 3 months

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TUHS January 2019