[ih] Fwd: As Flag Day approaches at CMU
Guy Almes
galmes at tamu.edu
Sat Sep 6 08:13:34 PDT 2025
Hi Clem,
My experience with CMU's 360/67 was running batch jobs using its
wonderful Algol-W compiler. Excellent for teaching programming with.
C.mmp was an experimental multiprocessor designed by Bill Wulf and a
number of CS students and staff in the very early 1970s. As hardware,
it was an elegant multiprocessor with up to 16 separate PDP-11s, each
with its own local memory and peripherals, all sharing a massive (2
MBytes!) shared (mostly) core primary store. As software, it ran a
capability-based operating system called Hydra. The vast majority of
the programming I did in research related to my thesis project dealt
with C.mmp. A wonderful experimental system with enough flaws that it
was not going to be the next big thing.
But C.mmp was connected to the ARPAnet through one of the ports on
CMU's IMP. This was almost entirely used to support logging into C.mmp
from the department's PDP-10s. Also, since the wonderful Bliss-11
compiler we used actually ran on the PDP-10s, we'd compile our programs
there and then move them over the ARPAnet to C.mmp for execution.
So, at least in this case, the ARPAnet was, in effect, our LAN for
moving files and logging in to various systems within the CMU CS
department, including this highly experimental system.
A medium-good explanation can be found at
<https://en.wikipedia.org/wiki/C.mmp>
There are probably a number of ARPAnet sites where the ARPAnet served
this LAN role in the pre-Ethernet days.
-- Guy
On 9/6/25 8:46 AM, Clem Cole via Internet-history wrote:
> The early maps show the CMU IBM 360/67 running TSS, but I was a programmer
> in that shop. I don't think we ever had an NCP that worked with TSS. It
> certainly was not on the ARPANET when I was a programmer. However, I note
> that later maps, the fourth port on the CMU IMP starts to show it as
> C.mmp. Guy Almes might remember if that was ever active.
>
> Clem
>
> On Sat, Sep 6, 2025 at 7:22 AM Steve Crocker via Internet-history <
> internet-history at elists.isoc.org> wrote:
>
>> IIRC, UCSB , Arpanet node #3, had an IBM 360/75 running OS/MVT. Prior to
>> being connected to the Arpanet they had a long-suffering attempt to add
>> interprocess communication to operating system so two partitions could
>> communicate with each other. As I understand it, they never got it
>> working. However, when they connected the machine to the IMP, two
>> partitions could communicate with each other by treating them as processes
>> communicating over the Arpanet.
>>
>> Steve
>>
>> Sent by a Verified
>>
>> sender
>>
>>
>> On Sat, Sep 6, 2025 at 4:34 AM Olivier MJ Crépin-Leblond via
>> Internet-history <internet-history at elists.isoc.org> wrote:
>>
>> > Fascinating.
>> > I notice there's not mention of IBM VM/CMS which was the mainstay of
>> > EARN/BITNET.
>> >
>> > Is it because there were no such computers on the Arpanet?
>> > Kindest regards,
>> >
>> > Olivier
>> >
>> >
>> > On 06/09/2025 04:33, Barbara Denny via Internet-history wrote:
>> > > Oops. Somehow a . got inserted in the url.
>> > > This one should work.
>> > > https://urldefense.com/v3/__https://self-issued.info/Smiley/
> Arpanet_Protocol_Thread.html__;!!KwNVnqRv!
> CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-
> dNCOj5OdQHl1_fkgq7XBGIa8quLvQ$ <https://urldefense.com/v3/__https://self-issued.info/Smiley/Arpanet_Protocol_Thread.html__;!!KwNVnqRv!CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-dNCOj5OdQHl1_fkgq7XBGIa8quLvQ$>
>> > > barbara
>> > > On Friday, September 5, 2025 at 08:10:41 PM PDT, Greg Skinner via
>> > Internet-history<internet-history at elists.isoc.org> wrote:
>> > >
>> > > forwarded for Barbara
>> > >
>> > >> ----- Forwarded Message -----
>> > >> From: Barbara Denny<b_a_denny at yahoo.com>
>> > >> To: Internet-history<internet-history at elists.isoc.org>
>> > >> Sent: Friday, September 5, 2025 at 07:49:12 PM PDT
>> > >> Subject: As Flag Day approaches at CMU
>> > >>
>> > >> Some of you might be interested in this link.
>> > >>
>> > >> https://urldefense.com/v3/__https://self-issued.info/S.miley/
> Arpanet_Protocol_Thread.html__;!!KwNVnqRv!
> CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-
> dNCOj5OdQHl1_fkgq7XBGJUHbeQvw$ <https://urldefense.com/v3/__https://self-issued.info/S.miley/Arpanet_Protocol_Thread.html__;!!KwNVnqRv!CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-dNCOj5OdQHl1_fkgq7XBGJUHbeQvw$>
>> > >>
>> > >> It covers cmu messages as flag day approaches. They were recovered
>> > when Jeff Baird was trying to find Scott Fahlman's smiley :-) bboard
>> post.
>> > >>
>> > >> The messages include when the ARPAnet temporarily shut off NCP twice
>> > before flag day. Vint, was one of those times you ????? I think I
>> remember
>> > you mentioned doing this but I wouldn't be surprised if I am wrong.
>> > >>
>> > >> barbara
>> >
>> > --
>> > Internet-history mailing list
>> > Internet-history at elists.isoc.org
>> > https://urldefense.com/v3/__https://elists.isoc.org/mailman/listinfo/
> internet-history__;!!KwNVnqRv!
> CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-
> dNCOj5OdQHl1_fkgq7XBGKpsVb63A$ <https://urldefense.com/v3/__https://elists.isoc.org/mailman/listinfo/internet-history__;!!KwNVnqRv!CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-dNCOj5OdQHl1_fkgq7XBGKpsVb63A$>
>> > -
>> > Unsubscribe:
>> >
>> https://urldefense.com/v3/__https://app.smartsheet.com/b/
> form/9b6ef0621638436ab0a9b23cb0668b0b?
> The*20list*20to*20be*20unsubscribed*20from=Internet-history__;JSUlJSU!!
> KwNVnqRv!
> CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-
> dNCOj5OdQHl1_fkgq7XBGLbOnOieg$ <https://urldefense.com/v3/__https://app.smartsheet.com/b/form/9b6ef0621638436ab0a9b23cb0668b0b?The*20list*20to*20be*20unsubscribed*20from=Internet-history__;JSUlJSU!!KwNVnqRv!CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-dNCOj5OdQHl1_fkgq7XBGLbOnOieg$>
>> >
>> --
>> Internet-history mailing list
>> Internet-history at elists.isoc.org
>> https://urldefense.com/v3/__https://elists.isoc.org/mailman/listinfo/
> internet-history__;!!KwNVnqRv!
> CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-
> dNCOj5OdQHl1_fkgq7XBGKpsVb63A$ <https://urldefense.com/v3/__https://elists.isoc.org/mailman/listinfo/internet-history__;!!KwNVnqRv!CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-dNCOj5OdQHl1_fkgq7XBGKpsVb63A$>
>> -
>> Unsubscribe:
>> https://urldefense.com/v3/__https://app.smartsheet.com/b/
> form/9b6ef0621638436ab0a9b23cb0668b0b?
> The*20list*20to*20be*20unsubscribed*20from=Internet-history__;JSUlJSU!!
> KwNVnqRv!
> CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-
> dNCOj5OdQHl1_fkgq7XBGLbOnOieg$ <https://urldefense.com/v3/__https://app.smartsheet.com/b/form/9b6ef0621638436ab0a9b23cb0668b0b?The*20list*20to*20be*20unsubscribed*20from=Internet-history__;JSUlJSU!!KwNVnqRv!CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-dNCOj5OdQHl1_fkgq7XBGLbOnOieg$>
>>
> --
> Internet-history mailing list
> Internet-history at elists.isoc.org
> https://urldefense.com/v3/__https://elists.isoc.org/mailman/listinfo/
> internet-history__;!!KwNVnqRv!
> CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-
> dNCOj5OdQHl1_fkgq7XBGKpsVb63A$ <https://urldefense.com/v3/__https://elists.isoc.org/mailman/listinfo/internet-history__;!!KwNVnqRv!CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-dNCOj5OdQHl1_fkgq7XBGKpsVb63A$>
> -
> Unsubscribe:https://urldefense.com/v3/__https://app.smartsheet.com/b/
> form/9b6ef0621638436ab0a9b23cb0668b0b?
> The*20list*20to*20be*20unsubscribed*20from=Internet-history__;JSUlJSU!!
> KwNVnqRv!
> CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-
> dNCOj5OdQHl1_fkgq7XBGLbOnOieg$ <https://urldefense.com/v3/__https://app.smartsheet.com/b/form/9b6ef0621638436ab0a9b23cb0668b0b?The*20list*20to*20be*20unsubscribed*20from=Internet-history__;JSUlJSU!!KwNVnqRv!CwuvUVeri51FGqp0FEJ_k7BVZip4r2gnntIIxgbXrlSDBy2g5L9yc4_IAhbj_znc-dNCOj5OdQHl1_fkgq7XBGLbOnOieg$>
>
More information about the Internet-history
mailing list