TUHS

tuhs@tuhs.org

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6557 discussions

by Norman Wilson

Arnold: ISTR that the vaxen did have such things. Or rather, I ran some BSD 780s for several years and I don't remember having to set the date / time every time I did a reboot. They sat in a data center, so I may have never done a cold boot from power on. It was a LONG time ago now, so there's undoubtedly lots that I just plain don't remember. ==== I believe all the VAXes had time-of-year clocks, though the implementation and the method of access varied from model to model. On `Big' VAXes, the clock was considered part of the console front-end, and accessed through the model-specific console scheme. MicroVAXes had no console front-end; I believe the clock was accessed through registers, but it was an off-the-shelf digital-watch chip with some funny format (separate registers for year, month, day, hour, minute, second). So they all had proper battery-backed-up clocks, but of many different types. It wasn't as simple as reading a single counter out of a register, sensible as that might seem. If anyone's really interested I can dig up details for the several models of Big and MicroVAX I dealt with; I still have all the code lying around. Norman Wilson Toronto ON

7 years, 8 months

OT: Konrad Zuse

by Dave Horsfall

We lost Konrad Zuse on this day in 1995; he invented the world's first programmable computer -- the Z3 -- which was unfortunately lost in the Berlin bombing during 1943. -- Dave Horsfall DTM (VK2KFU) "Those who don't understand security will suffer."

7 years, 8 months

Date madness

by jnc＠mercury.lcs.mit.edu

Heh, my V6 machine thinks (via 'date') that today is _Monday_, December 12th. Oddly enough, 'cal 17 2017' on it produces the right thing. Guess the date code is probably missing the '400 year' exception. Noel

7 years, 8 months

shell PS1/PS2 which survive cut-paste

by George Michaelson

I tried a long time ago to set PS1 and PS2 to character sequences which would permit cut-paste to work. I failed, but I didn't try very hard. The choice of "# " and "> " interests me. Because roots prompt of "hash" has a side effect of making a cut-paste over it a comment in most shells. But.. it predates being *able* to cut-paste so it has to be a side-effect, not a design choice. "> " is more dangerous in cut-paste. Which again feels like a side-effect both by anachronistic time effects, and intent: nobody would be that suicidally mad to make cut-paste invoke shell pre-forming the command sequence which neccessarily zeros out the > targets before executing the cmd... -G

7 years, 8 months

Re: [TUHS] Date madness

by jnc＠mercury.lcs.mit.edu

> From: Arnold > One would think that SIMH I'm using Ersatz-11... > into the simulated computer's time of day clock. What Time of Day clock? We're talking PDP-11's here! :-) The very last DEC models of the -11 (/93-94) had a ToY clock; I'm pretty sure none of their others did. And of course V6 long pre-dated the /93-94. Noel

7 years, 8 months

Re: [TUHS] Date madness

by Doug McIlroy

>>> Flipping it to unsigned int was the quickest way out to kick the can until Sun Feb 6 06:28:15 2106. If you have source it’s incredibly trivial to change, and nothing changes size wise. >> >> Easy, but perhaps unwise. The sign bit is a potential escape hatch for >> times, just as it is for characters in UTF-8. > > I'm not sure what you're suggesting - UTF-8 works because it's a variable length encoding - a variable length timestamp might be interesting as an academic exercise, but there's no way for time() to specify how much space is needed, or be informed of how much space is allocated Like UTF-8, a variable-length time would be something normal programs aren't supposed to see--it would be a format for external media (i.e. file systems). Times in inodes would be variable-length. Times returned by stat() and time() would be full length. Only the kernel needs to know the encoding. One may note that inodes already use a variable-length encoding for the list of physical block addresses, so there is nothing radical here. I admit, though, that if the kernel can tell "old" from "new" inodes, then they could have different time encodings rather than one variable-length encoding. Doug

7 years, 8 months

Re: [TUHS] Early Clones / Rewrites for TUHS archives

by jnc＠mercury.lcs.mit.edu

> From: Clem Cole > It would be nice to have section in TUHS of any early clones that could > be collected. The Unix Tree does have a section for "Unix Clones", and it has Coherent, Xinu, Minix and some early Linuxes. Another one that's missing (although in a different category) is Ultrix-32.> Noel

7 years, 8 months

Partition table rationales?

by Random832

Is there any information on the rationales behind the sizes and positions of the hardcoded partitions in the rp/hp drivers in V6? There are odd gaps of unused space between ones that appear to be intended to be used together (I think I have some pieces of the puzzle worked out below, but not all). For the rp driver, only rp[01] uses the whole disk - rp2 and rp3 are 9200 blocks. The hp partitions looked more complicated, but it looks like the manpage is wrong about where partition 2 starts - 84018 vs 48018. Partitions 0123 are 161584 blocks, 4567 are 162400 blocks. 4567 start on 100-cylinder boundaries, but are only a bit over 97 cylinders long - in fact, they are the same length as rp[01]: 203 RP03 cylinders. rp6 and rp7 are not mentioned in the manpage, and are 15600 blocks, making rp[65] and 47 reasonably non-wasteful configurations. Is there something special about 9200 blocks? rp2 and rp3 are that size, and hp1 is that size rounded to the next cylinder. V7 is much simpler: rp0 is the whole disk, 123 is a non-overlapping set with no wasted space. hp[0145], 016, and 017 are non-overlapping sets.

7 years, 8 months

Re: [TUHS] Date madness

by Doug McIlroy

> Flipping it to unsigned int was the quickest way out to kick the can until Sun Feb 6 06:28:15 2106. If you have source it’s incredibly trivial to change, and nothing changes size wise. Easy, but perhaps unwise. The sign bit is a potential escape hatch for times, just as it is for characters in UTF-8. Doug

7 years, 8 months

Difference in purpose of /var/spool vs /var/lib

by Grant Taylor

Can anyone enlighten me on the effective difference in the use of /var/spool vs /var/lib? It's my understanding that spools are for files that are in transit. Effectively like packages moving through a shipping depo or people waiting in line. I.e. they come in, they hang around for a while, and then they leave. I'm of the opinion that files in /var/lib should stick around longer and are not nearly as dynamic (if at all, save for code updates). As sure as I type this, I can't think of a reason library files would go under /var vs a different */lib directory. Does it make any difference if the files are actually executed and / or consumed on the system? I don't consider the POP3 / IMAP / NNTP server to be processing files when people access messages / articles (read: files) via the respective protocols. Back story: I'm considering writing something that will download a file every day and process the last day's / week's / month's file(s) to generate output which is itself stored elsewhere. - I feel like these files should live in the /var/spool/<bla> subdirectory. -- Grant. . . . unix || die

7 years, 8 months

Re: [TUHS] Date madness

by jnc＠mercury.lcs.mit.edu

> From: Tom Ivar Helbekkmo > My /83s have them, but I'm not so sure it's a feature of the CPU board: > there's this thought nagging in the back of my head that the ToY thing > actually sits in the front panel module with the various buttons on it. /83 documentation seems to be very thin on the ground, alas. It's definitely not the CPU; the KDJ11-B CPU (of the /83) manual (EK-KDJ1B-UG-001) makes no mention of it; and in the PDP-11/94E System User and Maintenance Guide (EK-KDJ1E-UG-001), section D.2 "PDP-11/94 and 11/84 Hardware Differences" (the /?3 and /?4 models use the same CPU board, but a different backplane, with QBUS/UNIBUS converter, so this could equally well be titled "PDP-11/93 and 11/83 Hardware Differences") says "Time of Year Clock", indicating the 83/84 don't have one. Several companies made after-market ToD clocks to plug into the QBUS, e.g. here: https://www.ebay.com/itm/371284594072 Is something like that what your /83 has? Noel

7 years, 8 months

Other history lists...

by Grant Taylor

Does anyone know of any other similar history discussion mailing lists / newsgroups to discuss things like Mainframes or (Open)VMS? I have some questions as I try to broaden my horizons, but I don't think they fit in the TUHS context. -- Grant. . . . unix || die

7 years, 8 months

V7 Addendem

by Warner Losh

>From the tuhs web site: "This is a set of addenda to Seventh Edition Unix, possibly put out by the Labs." and "The identity of the person who donated them is unknown." Two questions: Was this put out by the Labs? Second: There was recently a discussion about a tape found at some public location during an early Unix user group meeting. Is this that tape? Warner

7 years, 8 months

Re: [TUHS] Date madness

by jnc＠mercury.lcs.mit.edu

> From: Arnold > So how did you manage to lose a whole year? Time travel? :-) No, I just haven't booted the V6 often in the last year, and when I did, I never bothered to reset the time; so it was still on Nov, 2016. Noel

7 years, 8 months

Re: [TUHS] Date madness

by jnc＠mercury.lcs.mit.edu

> So, I looked at the code, and the bug is not obvious. Because there _was_ no bug!!! :-) It was saying December 12 was a Monday because the _year_ was still set to _2016_, and in 2016, December 12 _was_ a Monday! {Smacks forehead!} Noel

7 years, 8 months

Re: [TUHS] Date madness

by jnc＠mercury.lcs.mit.edu

> Guess the date code is probably missing the '400 year' exception. So, I looked at the code, and the bug is not obvious. (The routine for detecting leap years in V6's ctime.c is so minimalistic it actually works for 2000!) The version I'm currently running had been worked on some, to have a hack fix for the overflow of the number of 8-hour periods since the epoch ("hack" since the 'fixed' version will break in 2029 or so), and I was worried that 'fix' was wrong and caused the week-day problem, but I don't think so. Noel

7 years, 8 months

The French SOL Project

by Clem Cole

In the early 1980s, a bunch of French researchers set out to build a clone of UNIX/V7 in Pascal (using a ukernel IIRC). The project was the SOL project [Gien, 1983]. I believe it eventually begat the Chorus system (which was C++); which UI was going to use for System V/R5 before it all blew up. 1) Does anyone know what happen to SOL? Was it finished, deployed, used for anything? 2.) Did the sources and doc survive (and who owns the IP)? I think those should be in the TUHS archives, as I think this was the first attempt at a rewrite of UNIX in something other than C (or assembler). 3.) On a similar thought, did the Chorus code survive and who owns the IP? Clem [Gien, 1983]*“The SOL Operating System*”, Michel Gien, USENIX Association, 1983, Proceedings of the Summer ’83 USENIX Conference, Toronto, On, Canada, July, 1983, Pages 75-78

7 years, 8 months

Re: [TUHS] Early Clones

by Rudi Blom

actually not an early clone but a late(r), Philips MPX (Multi-processor UNIX) based on SystemV running on Moterola CPUs. Mostly sold in the (Retail) Banking Industry as branch server. The "M" was more related to having various boards running their own UNIX. That would be an Ethernet board and one Networking board for SDLC and X.25. These boards run their own copy of unix to 'offload' the main CPU. I've worked with this UNIX but more a system tester, interface to National Sales Organisations. No idea where the source is, but guess it would be IP of Philips (or DEC, or Compaq, or HP, or HPE) if anyone still remembers that is. For a (very) short while there was also an Intel CPU based version, but dropped in favour of SCO UNIX when DEC bought Philips Computer division. A very little bit in this 1987 article. https://www.cbronline.com/news/better_late_philips_enters_the_uk_unix_marke… Cheers, uncle rubl

7 years, 8 months

Re: [TUHS] Date madness

by jnc＠mercury.lcs.mit.edu

> From: Warner Losh > So at some point you had to hack things in to make 20xx work, no? I had a number of date issues with V6; more here: http://mercury.lcs.mit.edu/~jnc/tech/V6Unix.html#Issues That one was the easiest to fix! (Although this one will probably also be pretty easy, too.) Noel

7 years, 8 months

Re: [TUHS] V7 Addendem [ really lawyers and AT&T consent decree ]

by jnc＠mercury.lcs.mit.edu

> From: Clem Cole > IP and datagrams were very much built on no central control Well, yes and no. One can easily have a centrally controlled datagram network (q.v. the ARPANET) - although it's true that its path-selection algorithms, etc were not centrally controlled - but other aspects of the network were. (Interestingly, after various routing disasters the Internet caused by improper configuration, some aspects of path selection in _parts_ of it are now effectively centrally controlled; but I digress.) The IP Internet was designed with no _overall_ central control, but as a collection of autonomous entities. > In the end, it was MetCalfe's law (which was formulated on observations > about the phone system) that caused IP to win Over any and all comers, including other decentralized datagram networks like CLNP. MetCalfe's law doesn't talk about decentralized, it's just about 'first to field'. > all want to see the net neutrality go away This whole 'net neutrality' campaign drives me completely crazy. If all people wanted was a rule saying 'ISPs can't give third parties _worse_ service, or - more importantly - deny service altogether, unless those parties pay up' (i.e. what would amount to targeted extortion), I'd be _all for_ a rule like that. But the 'net neutrality' aficionados (most of whom, I'm fairly sure, are not aware of/thinking about these details) are all signing up for a much more expansive rule, one that says 'no ISP can offer anyone _better_ service for paying more money' - which is quite different. My problems with this latter form are two-fold. First, what's wrong with that anyway? Do we have a rule saying you can't get better road service if you pay? Absolutely not - restricted toll lanes are becoming more and more common. So there's clearly no societal agreement on this principle. (I suspect this 'net netrality' campaign has as a goal some sort of 'forced equality' thing - unless the people behind it simply don't even understand the difference.) Second, that rule is, with a little extra work on the ISPs' part, ineffective anyway. All they have to do is build _two_ networks, one better provisioned than the other - and priced accordingly. You want better service? Sign up for the second network; you'll pay more, but it's your choice. Noel

7 years, 8 months

Re: [TUHS] V7 Addendem [ really lawyers and AT&T consent decree ]

by jnc＠mercury.lcs.mit.edu

> From: George Michaelson > I didn't mean to disrespect the people who did the models or the > protocol or standards work btw. Oh, I personally have no problem with you saying hard things about this work, as long as it's what you really think. One never finds the truth unless one is willing to look hard, neh? And I'm pretty sure Dave Clark (who was a leading light in IntServ) would be OK with you doing so too (I worked very closely with him for years, to the point where I deputized for him at meetings). I honestly don't remember exactly what my take was on IntServ and RSVP; I'd have to go look. I recollect seeing the case that _if resources were limited_, certain classes of application (I guess we called them 'inelastic') would need reservations to work properly. So I was probably susceptible to the argument that 'if we've got bandwidth to light our <insert flammable objects> with, we don't need resource reservation'. And I remember being not _thrilled_ with RSVP, but I don't recall exactly why. But, as, you said, wrong list. Maybe internet-history: http://mailman.postel.org/mailman/listinfo/internet-history if you did want to delve into it. Noel

7 years, 8 months

Re: [TUHS] MERT?

by jnc＠mercury.lcs.mit.edu

> From: Jon Steinhart > Probably the best person to ask is Heinz Lycklama. I checked my email log for my previous MERT enquiries, and that's the exact same advice I got from Brian Kernighan when I asked him (a couple of years back) if he had any suggestions for tracking it down. I guess I need to finally get a 'round tuit'... unless there's someone else here who knows him well, and wants to give it a go. Noel

7 years, 8 months

Re: [TUHS] V7 Addendem [ really lawyers and AT&T consent decree ]

by jnc＠mercury.lcs.mit.edu

> From: George Michaelson > I don't think this list is the right place to conduct that particular > debate. Not disagreeing; my message was a very short gloss on a very complicated situation, and I wasn't trying to push any particular position, just pointing out that work (whether the right direction, or not, I didn't opine) had been done. > Its true RSVP didn't get traction, but the economics which underpin it > are pretty bad, for the current Internet model of settlement Yes, but would _any_ resource reservation system, even one that _was_ 'perfect', have caught on? Because: > it would not surprise me if there is ... more dropped packets than > strictly speaking the glass expects. This is related to something I didn't mention; if there is a lot more bandwidth (in the loose sense, not the exact original meaning) than demand, then resource reservation mechanisms buy you nothing, and are a lot of complexity. While there were bandwidth shortages in the 90s, later on they pretty much went away. So I think the perception (truth?) that there was a lot of headroom (and thus no need for resource reservation, to do applications like voice) played a really big role in the lack of interest (or so people argued at the time, in saying IntServ wasn't needed). Noel

7 years, 8 months

Re: [TUHS] V7 Addendem [ really lawyers and AT&T consent decree ]

by jnc＠mercury.lcs.mit.edu

> From: Steve Johnson > Recently I've been attempting to Skype on a group call with 5 people in > Europe. I would LOVE to have a guaranteed bandwidth for my call. The Internet engineering community did quite a bit of work on resource guarantees. (Google 'IntServ' and 'RSVP' - the latter is the control protocol.) Unfortunately, there was never much interest in it. People started doing voice with just plain 'best effort' service, and I guess it worked 'well enough' that nobody was interested in IntServ/RSVP. Noel

7 years, 8 months

Re: [TUHS] net neutrality

by jnc＠mercury.lcs.mit.edu

> From: Larry McVoy <lm(a)mcvoy.com> > Did you read the reddit link I sent? No, because I despise Reddit. > Because if you had you wouldn't be asking this. Now that I look at it, most of what I lists is ISP's _blocking_ sites. I _already_ said I wanted to see a rule preventing that. > unregulated businesses will do whatever they can to make more money with > absolutely no concern about the consequences Sure - like content providers. Noel

7 years, 8 months

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TUHS