It's another similar to the last two. I've
uploaded a version to youtube until the conference has theirs ready. It's a private
link, but should work for anybody that has it. Now that I've given my talk it's
cool to share more widely.
The link at the end is wrong.
https://github.com/bsdimp/bsdcan2020-demos is the proper
link.
Please let me know what you think.
Watched it & liked it a lot!
I have one nit-pick in the section on early networking: BBN's VAX TCP did not allow
the ‘/dev/net/host’ syntax. That particular semantic comes from UoI’s NCP Unix, where the
8-bit host number was encoded in the minor number of character special file ‘host’ - but
it did not carry through to the BBN code.
Other systems used something similar. The Chaos network code made namei() break when it
recognised the Chaos driver and left the remainder of the path for the driver to fetch
& parse. I’m also being told that Greg Chesson experimented with using the given name
of a Datakit channel device as the connection string for the switch, but that this
approach was abandoned early on.
In my view, exposing the host names through integration in the Unix file name space makes
a lot of conceptual sense, but it unfortunately falls down on the practicalities, with the
host name set being hard to enumerate (it is large, distributed and not stable - even back
then).
A question mark is hard pin-pointing the start of Unix networking to V4 / 1974. Yes, that
is the earliest evidence we currently have. However, Sandy Fraser says that Spider came
into operation in 1972 and it must have connected to something. Maybe that something was a
lab-bench test setup, but it could have been a computer - maybe even one running Unix.
There is another candidate for earliest Unix networking as well. The tech memo’s from
Heinz Lycklama include one on the Glance terminal. That memo includes a section on the
network used, referencing a 1973 report by D.R. Weller, "A High-Speed I/O Loop
Communication System for the DEC PDP-11 Computer”. That computer appears to be an 11/45
running Unix and the loop is not Spider (nor the Pierce loop discussed in 1970/71 BSTJ). I
have an off-list question outstanding to better understand this.