Does anyone remember the reason that processes blocked in I/O don't catch
signals? When did that become a thing, was that part of the original
design or did that happen in BSD?
I'm asking because I'm banging on FreeBSD and I can wedge it hard, to
the point that it won't recover, by just beating on tons of memory.
--
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Larry McVoy lm at mcvoy.comhttp://www.mcvoy.com/lm
> From: Deborah Scherrer
> the initial research on the arpanet was done at Lawrence Berkeley Lab
I was interested to find out more about this: I looked in Hafner, "Where
Wizards Stay Up Late" (the popular, but well-researched, book on the ARPANET)
but couldn't find 'Lawrence Berkeley' or 'LBL' in the index (although it did
have Lawrence Livermore); there were a couple of 'Californa, University of (at
Berkeley' listings, but none covered this. In Abbate, "Inventing the Internet"
(the first half of which covers the ARPANET), nothing under any of 'Lawrence
Berkeley', 'LBL', 'Berkeley' or 'California'.
In Norberg/O'Neill, "Transforming Computer Technology" (the standard ARPA
history, which has extensive coverage of the ARPANET project), there was one
entry for 'Californa, University (Berkeley)', which might be about the work
you refer to:
"IPTO issued a contract for a 'network' project at the Berkeley campus of
the University of California ... because of the presence at Berkeley of
specialists in programming languages and heuristic programming".
But there's nothing about what was produced. Is there anything you can point
me at that provides more detail? Thanks!
Noel
> From: Dave Horsfall
> The ARPAnet reached four nodes on this day in 1969 (anyone know which?)
SRI, UCSD, UCLA, Utah:
http://www.chiappa.net/~jnc/tech/arpageo.html
All West Coast, plus Utah. Next was BBN; if you look at the IMP numbers, in
HOSTS.TXT, they were assigned in order of installation.
> at least one "history" site reckoned the third node was connected in
> 1977 ... Well, I can believe that perhaps there were only three left by
> then...
No:
http://www.chiappa.net/~jnc/tech/arpalog.html
1977 was not too many years before the peak in size (with the MILNET split
coming in October, 1983). Per:
http://www.chiappa.net/~jnc/tech/arpanet.html
"Prior to the split, in 1983, there were 113 IMPs in the ARPANET; after the
ARPANET/MILNET split, the MILNET consisted of 65 nodes, leaving the ARPANET
with 68 nodes."
Noel
On Wed, Nov 29, 2017 at 08:00:55PM +0100, Steffen Nurpmeso wrote:
> Larry McVoy <lm(a)mcvoy.com> wrote:
> |On Mon, Nov 27, 2017 at 07:06:51PM -0500, Ron Natalie wrote:
> |> 1977 marks my entry into the world of UNIX. I've always stated there was
> |> only one person who truly understood nroff and he was dead.
> |> I mourn the fact that of all the UNIX greats I've met, I missed out on
> |> Ossanna.
>
> |I think one could argue that James Clark has a pretty good handle on
> |roff (having written the GNU version of nroff/troff/tbl/eqn/pic etc).
>
> And Werner Lemberg, who carried the torch for the last almost two
> decades. He brought in some really great improvements, like
> arguments for strings, which allows to write pretty much TeX like
> a.k.a. inline if you want to (as in "this is \*[I talic] text").
Yep. James exited stage left and Werner stepped in. I mean no disrespect
to anyone, I was just saying that James has a really good handle on roff,
he redid it all. I admire him for doing so (even though I curse the fact
that he did it in C++).
All,
Was Unix ever ported to a PDP8, or any other 12 bit environment, for
that matter? If not, why not? My understanding, such as it is, is that
Unix was created on the PDP7 - btw, thank you very much, Ken Thompson,
you definitely changed my world :), which is an 18bit machine, and that
it soon found its first real home on the 16 bit PDP11 series of machines
(an 11/20), and from there, ever upward or at least ever onward. I'm
curious about it for historical reasons, of course, but also because
I've been messing around in the PDP8 emulation world and enjoying the
excursion into simplified ISA and memory architectures.
-will
So tape I can see being more weird, but isn't raw disk just "don't put it
in buffer cache"?
>From what I've been able to gather early tape in Unix was dicey, something
about the driver doing seek. Was there more to it than that?
On Tue, Nov 21, 2017 at 02:33:55AM +0000, Clem Cole wrote:
> It???s not so much that they don???t mix, it???s not quite the same. Some
> coprocessor ideas work really well into the Unix I/O model, others don't.
> Raw disk and tape I/O ala a PDP11 or VAX for instance is not easy on an
> IBM channel controller or a CDC PPU.
>
>
>
>
>
>
>
>
> On Mon, Nov 20, 2017 at 6:45 PM Larry McVoy <lm(a)mcvoy.com> wrote:
>
> > On Mon, Nov 20, 2017 at 06:43:28PM -0500, Ron Natalie wrote:
> > >
> > >
> > > > I get that PDP-11 and VAX used memory mapped I/O but was that somehow
> > > exposed above the device driver layer? If so, I missed that, because I
> > had
> > > no conceptual or technical problem with talking to an I/O
> > >
> > > > channel, it was pretty easy. And I suck at writing drivers.
> > >
> > > There's nothing that restricts a device driver to memory mapped I/O.
> > You
> > > do what ever you have to do to initiate the I/O. Even the x86's
> > originally
> > > used special instructions to start the I/O (in/out). The DENELCOR HEP
> > > supercomputer (we did this port around 1983) we had to bounce I/O
> > requests
> > > off a separate I/O processor different from where the kernel was running.
> > > Similar constucts were used on other machines.
> >
> > Yeah, that's what I thought. But other people were saying that I/O
> > processors and Unix didn't mix. I don't get that, seems like whatever
> > the model is is hidden under the driver, that's the whole point of the
> > driver design is it not?
> >
> --
> Sent from a handheld expect more typos than usual
--
---
Larry McVoy lm at mcvoy.comhttp://www.mcvoy.com/lm
> From: Charles Anthony
> Entry points are usually defined as "foo$bar", where "foo" is the
> segment name, and "bar" an entry point in the segment symbol table. I
> believe that the degerate case of "foo$" is treated as "foo$foo" by the
> shell.
So I'm curious about how this, and additional names, interact. (For those who
aren't familiar with Multics, a segment [file, sort of] can have multiple
names. This is sort of like 'hard links' in Unix, except that in Multics one
name, the "primary name" is very slightly preeminent. See here:
http://web.mit.edu/multics-history/source/Multics/mdds/mdd006.compout
page 2-5, for more, if you're interested.)
So if I have a segment with primary name 'foo', and additional names 'bar' and
'zap', and I say 'zap' to the Multics shell, I assume it does a call to
zap$zap, which finds the segment with the primary name 'foo', and calls the
'zap' entry therein?
> Multics rulez; UNIX droolz
Dude, you clearly have Very Large brass ones to send that to this list! :-)
Noel
Early on, when multics was understood to have
one big, segemented address space, it was expected
that PL/I name qualification ($) would serve to address
segments. I do not know whether that idea was
actually implemented.
Doug
