22 May
2017
22 May
'17
10:29 p.m.
The Rand API is documented in a couple of papers that have been discussed
here previously. I'll have to do a little googling to find them. The
ChaosNET docs are the best MIT docs.
The API pretty much worked this way... there was one simple kernel hook.
A small mod was done to the old nami routine (what modern UNIX calls
'lookup'), as a path was being parsed, the rest of the path was left in
place made available to other routines.
Thus you could open: /dev/tcp/xxx and the string xxx was available in
call that was implementing tcp and was then able to be passed xxx as a
parameter. Hence, the traditional open/close/read/write was all that was
needed.
Joy codified a new API that was supposed to be more network centric and map
to different network protocols - the thinking being that
open/close/read/write were insufficient semantics for network operations.
Also, the only other issue at the time was that BSD's select(2) did not
exist, and the UNIX I/O were 100% synchronous. So some other mechanism
(also discussed here) needed to be created to avoid blocking in the
application. There were a couple of different schemes with V7's
multiplexor call was created by Chesson for DataKit (which was similar to
was used in the UofI code Arpanet code). Rand, UNET & Chaos had something
else that gave the save async function, who's name I've forgotten at the
moment, but I believe Noel posted the code for same in the last year from
one of the MIT kernels - we had used it at CMU that we had gotten from Rand.
On Mon, May 22, 2017 at 10:51 AM, Steve Simon <steve(a)quintile.net> wrote:
hi Clem,
do you have pointers to any documentation on the rand/MIT network API?
-Steve
On 22 May 2017, at 15:09, Clem Cole <clemc(a)ccc.com> wrote:
On Mon, May 22, 2017 at 5:28 AM, Paul Ruizendaal <pnr(a)planet.nl> wrote:
There are two other routes to TCP/IP on a PDP11
without split I/D:
- 3COM's TCP/IP package (initially an overlay over V7, soon after also
over 2BSD);
It's called UNET
I believe the source to this is lost.
So far that is true, there are a couple of leads including a couple of
unread tapes in my own basement. The original authors and I have been in
touch. Assuming we can find and recover it, there is still an open issue
of copyright.
.....
Note that these last two options have very different API's
Indeed...
and would not be so easy to work with.
Mumble ... it just means post-Joy sockets code does not 'just work.'
UNET uses the Rand interface, which is similar to the interface MIT used
for Chaos and Chesson used for the ARPAnet code at UofI, so there are
programs that talk to it. We had mail, ftp and telnet working just fine.
Back in the day and IIRC we were playing with a port of the MIT SUPDUP
code but I do not remember if that ever worked on the small address
machines.