> This one, perhaps:
> https://patents.google.com/patent/US3964059A/en
Yes, that's the Typo patent. Notice that it features "method and
apparatus". The bizarre idea of doing it in hardware was a figment of
the patent department's imagination. This was a dance to circumvent
the belief at the time that software could not be patented. Software
was smuggled in by stating that it was one way to realize the
apparatus in the patent disclosure.
The now obsolete belief was fallout from Gottsschalk v Benson, in
which the Supreme Court invalidated another Bell Labs patent, on a
trick to save a few cycles in converting integers between BCD and
binary. The grounds for rejection were roughly that software was math
(a "mental step") and therefore not patentable.
The Benson decision, written by William O. Douglas, makes ludicrous
reading: it argues, though the patent does not claim, that a patent on
this narrow method could be enforced against any program that converts
BCD to binary. Apparently Douglas thought that all black-box programs
for a given purpose were the same, although the patent office did not
so conflate different mechanical or electrical apparatuses that have a
common purpose.
Doug
> I am having a problem clearing a dup inode.
V6 had almost no tools for automagically fixing file system corruption.
To do it, you need to i) understand how the FS works (see:
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V6/usr/man/man5/fs.5
but it's pretty simple); ii) understand what the few tools (dcheck; icheck;
clri) do; iii) dive in.
I recall I used to use 'adb' a lot, to manually patch things when there was a
problem, so you'll want to study up on the 'db' syntax (no 'adb' in vanilla
V6, but for this, they are basically equivalent):
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V6/usr/man/man1/db.1
You'll have to use the non-raw version of the device (the raw version can only
read/write complete blocks), and then judiciously use 'sync' to flush the
updated blocks out to the 'physical' disk. (There are some corner cases where
data is stored elsewhere, such as when one is patching the inode of an open
file, but I'm going to ignore them.)
> # icheck -s /dev/rp0
'icheck -s' only rebuilds the free list; it doesn't help with any other error
(e.g. a block being assigned to two different files).
> 4244 dup; inode=323
Which is probably what is happening here. 'icheck':
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V6/usr/man/man8/icheck.8
is not telling you what _else_ is using that block, because it has already
forgotten that by the time it discovers this second claimant (it only keeps a
bit array of 'used' blocks).
> # icheck -b 323 /dev/rp0
Err, you wanted to say 'icheck -b 4244' to find out who else was using block
4244.
I'm not sure if 'fsck' would fix these; I have a V6 one, if anyone wants it.
The 'easy' way to fix this is i) copy the second file to somewhere else, ii)
delete the original, iii) re-build the free list (because the duplicate block
will now be in both the first file, and the free list), iv) examine both files,
and see which one has the smashed contents.
I'll turn this into a 'Fixing damaged V5/V6 file systems' article on the
CHWiki.
Noel
I think discussion of early Linux is in scope for this list, after all that is 30 years ago. Warren, if that is a mis-assumption please slap my wrist.
Following on from the recent discussion of early workstations and windowing systems, I’m wondering about early windowing on Linux. I only discovered Linux in the later nineties (Red Hat 4.x I think), and by that time Linux already seemed to have settled on Xfree86. At that time svgalib was still around but already abandoned.
By 1993 even student class PC hardware already outperformed the workstations of the early/mid eighties, memory was much more abundant and pixels were no longer bits but bytes (making drawing easier). Also, early Linux was (I think) more local machine oriented, not LAN oriented. Maybe a different system than X would have made sense.
In short, I could imagine a frame buffer device and a compositor for top-level windows (a trail that had been pioneered by Oriel half a decade before), a declarative widget set inspired by the contemporary early browsers and the earlier NeWS, etc. Yet nothing like that happened as far as I know. I vaguely recall an OS from the late 90’s that mixed Linux with a partly in-kernel GUI called “Berlin” or something like that, but I cannot find any trace of that today, so maybe I misremember.
So here are a few things that I am interested in and folks on this list might remember:
- were there any window systems popular on early Linux other than X?
- was there any discussion of alternatives to X?
- was there any discussion of what kernel support for graphics was appropriate?
> From: KenUnix
> things are missing:
> Undefined:
> _setexit
> _reset
> _seek
> _alloc
> _end
> Yes, I am trying to compile it on Unix v7.
Well, there's your answer. They are all in the V6 library. Here's
the source for setexit/reset:
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V6/usr/source/s5/reset.s
You do realize that if you got it compiled under V7 and ran it, it would
trash the disk, right? (The V6 and V7 filesystems are different; very
similar, but block nubers are 16 bits on V6, ans 32 bits on V7.)
> Is there a makefile?
No. No 'make' in V6. Which is why you find those 'run' shell files:
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V6/usr/source/s4/run
everywhere.
> From: John Cowan
> It was an update/rewrite of the MIT version.
Which one? There were two: "MIT's AI Lab", by CSTACY, Alan Wecsler, and me;
which Rob Austein re-wrote into "Alice's PDP-10". I thought the original was
centered around ITS, but my memory was poor (hey, it has been ~40 years :-),
it seems to sort of be about LISP Machines. Rob's version was about TWENEX
(yech). The original was written in 926, MOON's office; I can't believe he
put up with me hanging out there!
>> Although I like the old story about the person at their oral exam and
>> the Coke bottle in the window.
> Details?
So they're giving someone an oral exam. They can't make up their minds, or
something, and they ask the person to step out for a second. When the person
comes back in, they point to a Coke bottle sitting on a window-sill in the
sunlight, and ask them to examine it. The person notices that it's warm on
one side - the side facing the window. 'Why that side?', they ask. So the
person goes into a long explanation about how the curved glass must have
focused the light, yadda-yadda. WRONG! They turned it around while the
person was out of the room. I think that the person fails their oral. I
have no idea if it's a true story.
Steve Ward told another oral story which I'm pretty sure _is_ true, though.
They ask the candidate to design a state machine (or digital logic, I forget
which) which can tell if a number is divisible by three (I think I have the
details correct, but I'm not absolutely certain). So they describe one - and
then point out that you can feed the number in from either end (most or least
significant end first) - and proves that it will work either way! The
committee was blown away.
Noel
> I'm not sure if 'fsck' would fix these
Turns out it was called 'fcheck' when we had it.
> I have a V6 one
I'd already put it on my Web site, here:
http://ana-3.lcs.mit.edu/~jnc/tech/unix/s1/fcheck.c
if anyone wants it.
> From: "Ron Natalie"
> You had adb?
Yeah, MIT had a lot of stuff that 'fell off the back of a truck' (including
things like the circuit design tools, etc). Well, having an undergrad who was
in the famous Boy Scout troop at Bell helped... :-)
> From: KenUnix <ken.unix.guy(a)gmail.com>
> What I finally did was restore the ".disk" files from a previous backup
You may sit with Arlo Guthrie on the 'Windows user' bench. :-)
> From: "Theodore Ts'o"
> some have argued that if someone doesn't do backups of their research
> data, maybe they don't *deserve* to get their Ph.D. :-)
'Think of it as evolution in action.'
Although I like the old story about the person at their oral exam and
the Coke bottle in the window.
Noel
>> _end
> They are all in the V6 library.
Oops, not _end. In the V6 linker, "_end" is not defined if there are still
undefined symbols at the end of the linking run.
I remember finding this in some obscure place in the V6 documents; it's not
in 'ld(I)'. Anyone remember where it's discussed?
Noel
I've been doing a lot of reading of systems admin books lately including:
Frisch, E. (1991). Essential System Administration (3rd edition is my
fattest book other than Unabridged Shakespeare)
Hunter, B. H., & Hunter, K. B. (1991). UNIX Systems Advanced
Administration and Management Handbook (Opinionated praxis)
Nemeth, E., Synder, G., & Seebass, S. (1989). UNIX System Administration
Handbook (5th edition is another fatty)
Tons of other more recent drivel.
I have been working on my ancient and not so ancient Unix library for a
while now, and it's kind of funny. It seems like once I read a book, be
it new or old, I hardly need it anymore - most of them wind up back at
half-price books. The exceptions are those that I find myself going back
to over and over and over again and wow are those few and far between.
An example of one of the gems is S. R. Bourne's The UNIX System, another
is Kernighan and Pike's The UNIX Programming Environment, and a couple
of newcomers for me are Volumes 3 and 8 of O'Reilly's The Definitive
Guides to the X Window System. I've written in the margins so many times
with these that there are sections where I can't fit any more notes.
That's the kind of sys admin guide I'd like to hear about. So, my
question for y'all is, what did y'all think about sys admin texts as
they were coming out? Were they well received, were they water to a
dying horse, were they paperweights, what? If you are of the camp, "we
don't need no stinking admin guide", or "we did it all by muscle memory
and didn't use books", don't reply. I'm curious about the experience of
those of y'all who actually used them. Were there any early standouts
and why did they stand out?
Anything from 1970 on is fair game.
Later,
Will
P.S. Can you believe that 2000 is fast becoming 'history' worth
preserving? In 1997, we were rewriting our gas pump and credit card
transaction systems, which were written in C, to deal with upcoming Y2K
bugs. Oh, how the worm has turned :).
So now that I'm done futzing with the 4.1 manual for a while, I've decided to look around a few others to try and get a better feel for the continuity of different features as well as documentation practices between branches. On that note, the more I compare, the more continuity I find between PWB 1.0 and UNIX System III. Between that, various emails here, and some info from Clem, I feel fairly confident calling System III and V as well as the 4.1 in between PWB releases, at least as far as version continuity is concerned, so I may start using that nomenclature more here and there. On the flip side, the name UNIX/TS seems to bear less and less relevance outside of whatever efforts it did originate with in the late 70's. I eventually mean to aggregate all the references I've found together to develop a better picture of what that was, but just know that documentation consistency points to PWB 3, 4, and 5 as the true identity of the USG releases in the 80s, not UNIX/TS as I have referenced previously.
So now for an interesting bit of init history I've managed to piece together. The 4.1 manual still indicates the same init system as System III, based on a file called /etc/inittab but with a slightly different format and semantics from what we ultimately see in System V. That init, seen earliest thus far in PWB 3.0, seems to have been developed around that time. I'm struggling to find the email right now but I think someone on the list mentioned having written this one in either '79 or '80. As for the init in System V, it likely entered the PWB line from CB-UNIX based on the CB-UNIX 2.3 manual which can be found here: https://www.tuhs.org/Archive/Distributions/USDL/CB_Unix/cbunix_man5.pdf . I say likely as some recent perusal of the MERT Release 0 manual has now cast some doubt on that. So to start, CB-UNIX 2.3 appears to be somewhat contemporaneous with UNIX 5.0 in that the manual has pages labeled specifically UNIX 5.0. That said, the issue date on the front pages of the manuals is over a year apart, so the 5.0 additions could be just that, added pages after the formal 2.3 issue. Anyway, in common between them is an init system utilizing likewise a file named /etc/inittab, but with a slightly different format and some expanded functionality. The CB-UNIX manpage for this inittab(5) can be found on page 29 of the above document. I had never looked further in that one though, and a couple days ago, I was cataloging all of the pages present in that manual when I came across page 34. This is a page for lines(5) that simply says "No longer used. See inittab(5)." Curious, so perhaps this stream of init once called the file /etc/lines, then renamed it inittab to match PWB? The very next page answers part of that question. Page 35, also lines(5), contains a description of a file very similar to the inittab(5) entry except a line is 5 fields wide, including a "shellcm" field. Unfortunately, the remaining pages of this entry are not in the PDF, presumably this was a mistaken entry. I have another such mistaken entry in a moment. Anywho, what is there of the page indicates the id field actually had an impact on the /dev entry for the terminal line in that it would be named /dev/ln<id>, and goes on to say that if a line monitor other than /etc/getty is used this must be accounted for. So interesting little note there about using something besides getty for line monitoring. Otherwise the page reads pretty similar for what is there, indicating a likely continuity between this /etc/lines-based init and the CB variant of the /etc/inittab system. One interesting note is that /etc/lines supports C-style comments, /etc/inittab instead uses sh conventions. This lines file also indicates there is a run-level 7 which may have become the S run-level. The respawn and wait actions are there, and that's where the page cuts off, so no further evidence here of what was in /etc/lines in 1979 in CB-UNIX 2.1. By 1980 it is replaced with /etc/inittab.
So aside from the lines(5) stuff, this has been pretty well understood that System V init came from or at least strongly resembles CB-UNIX init as far as what is available documentation-wise. Well, as I mentioned above, the MERT Release 0 manual may shed some further light on this matter, albeit without fully illuminating it. So first, some MERT context. This document details the origins of MERT Release 0 pretty succinctly: https://www.tuhs.org/Archive/Documentation/Manuals/MERT_Release_0/Pgs%2037-… . Basically MERT 0 is the first "supported" release by the "Small Systems Planning and Development Department (8234)" at Murray Hill. The manual is based on the USG Program Generic Issue 3 version of the manual which was issued in early 1977. This manual, in turn, is from October 1977. This intro goes on to indicate that this product will eventually be released instead as "UNIX/RT" to accompany the in-progress "UNIX/TS" which is said here to be based on V7 with additions from USG Generic 3 and PWB. The MERT-specific portion of this manual is technically considered the second edition, presumably in that the first was the material maintained and distributed by Lycklama and Bayer. So in any case, the landscape of the time seems to be that V7 is starting to go around to the various streams, with UNIX/TS in the works to present it with USG/PWB stuff and then UNIX/RT being planned as the MERT-counterpart. This isn't quite my focus here, but does provide some UNIX/TS "stuff" that has been explained to varying degrees already. So where this all relates to the init though is this: https://www.tuhs.org/Archive/Documentation/Manuals/MERT_Release_0/Pgs%2001-…'s%20Manual%20for%20MERT.pdf On page 4 of this document is a list of pages that one must replace in a standard USG Program Generic 3 manual to produce a MERT Release 0 manual. In other words, this essentially lists which pages are changed for MERT. Of interest to this discussion is the V File Formats section on page 5. The instructions are to remove a page called "lines" and to add a page called "ttys". If you then go on to read through the manual, in section V, the ttys file suggests an init system akin to the research init system. This is also indicated by replacement of the init page itself with one describing a system closer to that of research than anything else: https://www.tuhs.org/Archive/Documentation/Manuals/MERT_Release_0/Unix%20Pr… . So based on this, it sounds like USG Generic 3 may have had the same /etc/lines init that we see hints of in CB-UNIX. This also then suggests that CB-UNIX 2.3 may have some basis in USG Generic 3 just like MERT. Based on yet another email I'm struggling to find, another user here had offered up some info regarding a USG Generic 2 manual he has from days past. That manual contained an init similar in flavor to the research init as well, indicating that this init system shows up as part of Generic 3.
So now for that other misprint that also bears some relevance. In the UNIX 4.1 manual I recently finished restoring, there was an errant gettydefs(4) page which was only the very last few lines of the manpage (basically the SEE ALSO) section. This file is not part of the pages one needs to discard to create a MERT manual and is not otherwise in the manual, so does not appear to be a part of Generic 3. However, this file does show up in CB-UNIX 2.3, and from there presumably gets sucked into System V, but the misprint suggests such a manpage existed somewhere that would've accidentally wound up in a UNIX 4.1 typesetting run. In any case, it is very well possible this init system may have started popping up in the PWB line before 5.0, but I can't confirm this.
In any case, to consolidate this information, here's a bit of a timeline for the init as I see it:
1975 May - V6 issued. Begins getting adopted as the standard base for various streams
1976 January - USG Generic 2 issued. From what has been discussed, this still has a research-style init based on /etc/rc and /etc/ttys
1977 March - USG Generic 3 issued. This allegedly features the addition of the /etc/lines-based init that eventually becomes System V init
1977 May - PWB 1.0 issued. Forks the documentation style quite a bit, starts trends that continue to System III and beyond, still research-style init
1977 October - MERT 0 issued. This uses Generic 3 as a base but reverts to a research-style init system
1979 January - V7 issued. Still using /etc/rc and /etc/ttys
1979 November - CB-UNIX 2.1 issued. This appears to be using a Generic 3-style /etc/lines init
1980 June - PWB 3.0 issued. This has the first known appearance of /etc/inittab but with a different implementation from USG Generic 3
1981 May - CB-UNIX 2.3 issued. By this point, /etc/lines has morphed into /etc/inittab and /etc/gettydefs has been added
1981 June - PWB 4.1 issued. The manual still features the PWB 3.0-style init but an errant page suggests at least possibly /etc/gettydefs support
1982 June - PWB 5.0 issued. The transformation is complete, PWB now uses Generic 3-descended init with CB-UNIX gettydefs
This all makes me wonder what PWB 2.0 and UNIX/TS (if it ever coalesced) would've used. Precedent would say PWB 2.0 would use research-style init and UNIX/TS would've likely used Generic 3 if the aim was continuity with the USG Generics, but who knows. Anywho, hope that info's helpful to anyone else researching init systems. Of course if you have info that contradicts or enhances any of this I'd love to hear it!
- Matt G.
With all your help I thought I would share a couple
of programs I had a hand in.
more.c is like 'more' for Linux. more abc.txt or cat abc.txt | more or ls
-l | more
pg.c is a 'pager' program. pg abc.txt def.txt
cls. is a clear screen home cursor program using VT100 codes. It works on
the console or telnet or putty.
All can be compiled and placed in /usr/bin
cc -o /usr/bin/cls cls.c
cc -o /usr/bin/pg pg.c
cc -o /usr/bin/more more.c
More to come. Enjoy.
Ken
--
WWL 📚
