Arnold Robbins writes:
>> There was no tac in V7 Unix. It was first posted to USENET, I don't
>> know by who, and picked up by Linux and *BSD.
That brought back memories, and to verify them, I checked the tac.c
source code in the latest GNU coreutils test release. It says
/* Written by Jay Lepreau (lepreau(a)cs.utah.edu)
GNU enhancements by David MacKenzie (djm(a)gnu.ai.mit.edu) */
So my memory was right that my old friend Jay was the author. Sadly,
we lost him in September 2008: see
https://www.legacy.com/obituaries/saltlaketribune/obituary.aspx?page=lifest…
Jay founded the influential Flux group in advanced networking research:
http://www.flux.utah.edu/profile/lepreau
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The Luderer paper on distributed Unix has the following paragraph:
"A new special UNIX interprocess communication mechanism is the fifo, which provides communication between unrelated processes by associating a new special file type with a file name. Since remote fifos are legal, they can be used for interprocessor communication between S-UNIX machines or between an S-UNIX machine and an F-UNIX machine.”
The paper is from late 1981. Maybe I’m especially mud-eyed today, but I cannot see FIFO’s implemented in V7..V8 or 4.1xBSD. When did FIFO’s become a standard Unix feature?
Paul
> These go all the way back to v7 unix, where ls has an option to reverse
the sort order (which could have been done by passing the output to tac).
A cool idea, but tac was not in v7. And tail didn't get the -r
option until v8.
As for rev, I don't know why it was first written, but one
use was to examine suffixes--a kind of thing that several
word lovers in the Unix lab were prone to do.
Apropos of using rev to make rhyming dictionaries, Walker's
Rhyming Dictionary was published decades before Noah
Webster's dictionary appeared and stayed in print
for about 200 years. Notionally the relation between
webster and walker is
rev <webster | sort | rev >walker
Doug
I’m making a little progress with early Datakit & Unix.
It would seem that there were various experimental protocols before URP was arrived upon.
The first protocol appears to have been designed by Chesson in 1979. One Fraser paper says: ""The first Datakit protocols used a packet structure that was aligned with cell boundaries. Chesson designed a file transfer protocol that transported data in variable length packets, each ending with a trailer.” I think this protocol is being described in his paper "Datakit Software Architecture” (vol. 2, pp. 20.2.1-20.2.5 Proceedings of the IEEE Int. Conf. on Communications, June 1979, Boston) - which unfortunately does not seem to be available in the IEEE online library. Maybe it will surface some day.
Next there was a protocol tied to a Datakit terminal interface board that used an 8-slot packet sequence/acknowledge mechanism that carried over into URP. Not much appears to have been published about this.
The most interesting experiment seems to have been a project by Luderer, Che and Marshall to build a Datakit-based distributed Unix in 1980/81. Marshall is credited by Fraser as one of the inventors of the URP protocol. The papers are “A virtual switch as the basis for distributed systems” and “A distributed unix system based on a virtual circuit switch” (available online from the ACM library).
The first has a good overview description of how early Datakit worked (including interface hardware) and describes the Network Kernel or “NK protocol”. It would seem that URP combines the flow & retransmission control from the terminal interface board with the concept of a single simple receiver algorithm from NK. Unfortunately the paper does not describe the design of the NK transmitter algorithm(s). It confirms that everything ran on V7, but it remains unclear how the Datakit channels were exposed to the user (I currently assume as a cluster of character devices, with the major number identifying the switch connection and the minor number identifying the channel - similar to what later would be used in V8).
The second has a description of a modified Unix system, where clients (“S-Unix”) talk to file servers (“F-Unix”), with the file servers mounted into the local file tree of the client. This appears to predate the work of Weinberger for the V8 network file system and its implementation appears different.
Questions:
- Are Luderer, Che and Marshall still around? (especially Bill Marshall might still recall some more details of the genesis of the URP protocol)
- Any recollections about S/F-Unix and how it did or did not influence V8-V10/Plan9?
Hi All.
I have a full set (hardcopy) of the USENIX "Computing Systems" journal.
It's just sitting on my shelf taking up space, and I'd like to give them to
someone who'll give them a good home.
So, first person to reply to me directly, who's willing to pay
shipping from Israel, gets them. (Payment via paypal, or preferably
a US dollar check sent to my US address.)
Thanks!
Arnold
I was just discussing this with someone today, and I realized this
information has fallen out of working memory, and I can't find it on
secondary storage anywhere... ;-)
Does anyone remember the release history and version numbering of Ultrix
for the VAX and MicroVAX (which I believe was referred to at various times
as Ultrix-32 and Ultrix-32M, until some point when the "-32" thing was
dropped, I think?) I was trying to remember what the various released
versions of Ultrix were. The person I was discussing with thinks he
remembers a version 1.4 and 1.6, before Ultrix 2.0. I honestly don't
remember any 1.x version beyond 1.2. Is there a timeline somewhere?
--Pat.
