Rob Pike:
For my taste, the various Unix file system switches that I've seen are too
firmly tied to the idea of blocks and disks and all that, making them less
flexible than they should have been. That's why the Plan 9 version is about
names and byte streams, to make it as general as possible.
=====
The only file-system switch I know well is that in the later
Research systems. It has nothing to do with disks or blocks.
It is about names and inodes: turn name to struct inode, read
arbitrary chunk of data, write arbitrary chunk of data, create
file, unlink file, abominable ill-defined system call that just
wouldn't die erm I mean ioctl, and so on.
It was certainly a cheap hack (as its author cheerfully admitted)
but it really was about I/O operations, not about simulating
disks. That's why it so easily supported /proc (the one that
was just about processes, not the misnamed Linux one that
is really about all things in the kernel so you don't need
/dev/kmem).
I don't know a lot about later VFSes like those in SunOS or
Linux or the BSDs. Blockiness might well have crept in in
support of memory-mapped I/O or in collaboration with the
buffer-cache implementation. The Research version was never
used directly to support different on-disk file system formats
(we did a different pjw cheap hack for the one case that
mattered in the kernel, and used the idea later developed
more by FUSE for other cases because speed didn't matter).
Norman Wilson
Toronto ON
> From: Michael Siegel
> there's no need to write out "less" every time. You can just alias that
> to "pg" without causing any harm and save two letters, which is an
> improvement for a task that is performed manually rather often.
It always surpised me that there wasn't more of this - abbreviating the names
of the most-used commands, to minimize typing - or more specifically,
run-length encoding them based on how frequently they were used, with the
most-used ones given the shortest names.
The MIT-DSSR PWB1 system had a pager called just 'p' (source here:
http://ana-3.lcs.mit.edu/~jnc/tech/unix/s2/p.c
if anyone wants to see it; the man page is dated Apr/77); and 'ls' was tweaked
to recognize the command name 'l' as an alias for 'ls -ls'.
Of course, aliases didn't exist in the shell back then, which was why the
command had to be coded to recognize the short form, and act differently.
(And /bin/l was linked to /bin/ls.)
'l' and 'p' are _still_ aliased in my shell,to this day!
> I hope it's okay that I chose to reply just to the list address and take
> all the other addresses out.
'That's not a bug, that's a feature!'
I always delete other addresses when replying to a list, unless I think someone
might not be subscribed to that list.
Noel
Hello All.
I have reconstituted Jon Bentley's DFORMAT preprocessor (troff and awk
source) and made it available on GitHub. See
https://github.com/arnoldrobbins/dformat.
This is an awk program that reads a description of data layouts, such
as registers or network packets, and generates PIC descriptions.
A Makefile generates PDF from the dformat.ms file using GNU troff.
Jon Bentley was helpful in the final stages, including contributing
his original files.
Enjoy!
Arnold Robbins
So in BSD family tree, there's a 2.9BSD-Seismo and a 2.9.1BSD listed.
Yet I can't seem to find them in the TUHS archive.
There is a 2.9-Patch directory dated 1985 the same as the date that's found
in the family tree. Is that the Seismo version?
And Kirk's archive has a 2.9pucc directory, which appears appears to be
from Purdue dated1987. How does this relate?
Thanks for any help you can provide
Warner
With some further reading and research (and the kind help of Heinz Lycklama and Jon Steinart) I’ve found that my understanding of early loop networks at Bell Labs confused several different systems. As far as I can currently tell there were at least 4 different loop networks developed around 1970 at Murray Hill.
1. The first one is the “Newhall Loop” (paper published in 1969). This loop used twisted pair cabling, ran at about 3Mhz and used variable sized messages. It seems to have used some sort of token to coordinate between hosts. This might have been the network that Ken Thompson recalled as having been in operation when he arrived at the labs in 1966.
2. The second one appears to have been the “Pierce Loop”, as described in 3 BSTJ papers submitted in 1970/71. This one was coax based, used T1 compatible frames and was used to connect H516 computers with various bits of equipment. It seems to have had a very short life span. Part of my confusion was that the term Pierce Loop also appears to have been used in a generic sense to denote loop networks with fixed-sized frames.
3. The third one is the “Weller Loop” (paper published in 1971). This loop used coax cabling, ran at 3.3Mhz and used fixed 35 bit frames/cells. Each cell carried one address byte and two data bytes. One participant on the loop was the controller and effectively polled the other stations. In its 1971 form it appears to have been for the H516’s only and was referred to as a “Serial I/O bus”. This is what Jon Steinhart was talking about.
The Weller loop was later redesigned (memo written in 1973) to interface with PDP-11’s as well. Heinz Lycklama used this loop in 1974 to connect several systems running (rump) Unix - see his paper about peripheral Unix here:
https://www.tuhs.org/Archive/Documentation/TechReports/Heinz_Tech_Memos/TM-… <https://www.tuhs.org/Archive/Documentation/TechReports/Heinz_Tech_Memos/TM-…>
This Serial I/O bus remained in use for several years at least.
4. The fourth and best known one is the “Spider Loop” (memo published in 1974, but operational from 1972). Twisted pair cabling, using T1 compatible frames. In use until about 1978. Main uses appear to have been the ‘nfs’ file store and the ‘npr’ remote printing service.
My conclusion from all that is that in 1974 Unix had access to two networks, Spider and the Serial I/O bus. For both, first experiments would have been in 1973. It is hard to be sure which one came first. If I had to venture a guess today, I’d say that Spider connected to Unix several months before the Weller loop (even though the 1st generation Weller loop preceded Spider). Maybe the conclusion is that both happened more or less in parallel: Weller was also one of the designers of the Spider hardware.
Hello!
I normally download items from the Society FTP site rather than from
the archival area on the website. And my clients kept getting bounced,
claiming that I should stop trying to connect frequently. Oddly enough
that was not the case a while ago. Was the archive recently updated
regarding hosting software?
On Windows it was FileZilla, and spun down to one rather than eight or
ten. And on the WSL SLES12 SP3 arrangement it was ncftp. Now
downloading the reports to go along with the one Paul made available
from the location is not important for today, I can wait until
tomorrow or the next day.
-----
Gregg C Levine gregg.drwho8(a)gmail.com
"This signature fought the Time Wars, time and again."
Rob Pike:
Yeah, p is all we need. I think it originated with td at UofT. I might have
brought it with me to Bell Labs, or recreated it. Probably the former.
====
The former, I think. The source code in V10 is very similar
to that you left behind at Caltech (where I first encountered
p). Most differences have to do with using opendir and readdir
rather than reading raw directories in the SPname code.
A further clue is that, even in V10, p.c begins
/*%cc p.c pad.o spname.o
*/
The tool that looked for such lines to tell it how to compile
things (I forget its name; was it comp?) doesn't seem to have
survived in the archival backup I have from Caltech HEP, but
I'm quite sure it came from U of T as well.
Norman Wilson
Toronto ON
> less(1) was actually an improvement
Hmm. Less is my favorite whipping boy for featuritis.
% less --help |wc
242 1331 12202
I am very happy with p.
Doug
The C in v7 is, canonically, the language described in K&R, right?
I must be doing something dumb.
I am getting Webb Miller’s “s” editor built there, and I am down to one function.
/* chop_arg - chop a function's argument to a maximum length */
static chop_arg(fcn, arg, maxlen)
int (*fcn)();
int maxlen;
char *arg;
{
char save;
save = arg[maxlen];
arg[maxlen] = '\0';
fcn(arg);
arg[maxlen] = save;
}
This doesn’t like the function pointer.
$ cc -c choparg.c
choparg.c:11: Call of non-function
So, uh, what is the obvious thing I am missing? How am I supposed to be passing function pointers in the C compiler that comes with v7?
Adam
