[ih] Nit-picking an origin story
Jack Haverty
jack at 3kitty.org
Sat Aug 16 12:29:23 PDT 2025
Yes - SAGE was an important part of the ARPANET's DNA. Frank Heart ran
the group that proposed and then built the ARPANET. He had previously
worked on SAGE, and no doubt brought that experience into the ARPANET.
My recollection is that BBN did most of the implementation work to get
the ARPANET switching fabric up and running. The larger network
community had to figure out all the myriad other issues involved with
getting wildly diverse computer systems to interact and cooperate, as
documented in the early RFCs.
I'm admittedly biased by my personal history, but I still think computer
networking started with Licklider and his early 1960s vision of a
"galactic network" (or perhaps it was "intergalactic"). Then again, it
may have been started by the Roman military. But they may have been
plagiarizing the Sumerians..... History is hard.
/Jack Haverty
Here's a summary, courtesy of Google's AI, from my search on "sage
lincoln lab frank heart":
---------------------
Frank Heart, a prominent figure in early computer networking, spent
approximately 15 years at MIT's Lincoln Laboratory working on the SAGE
air defense system and other projects. He later joined Bolt, Beranek and
Newman (BBN) and led the team that designed the first routing computer
for the ARPANET, a precursor to the internet. [1
<https://historyofcomputercommunications.info/interviews/Frank-Heart/>,
2 <https://www.computerhistory.org/collections/catalog/102702094>, 3
<https://en.wikipedia.org/wiki/Frank_Heart#:~:text=Frank%20Evans%20Heart%20(May%2015%2C%201929%20%E2%80%93,the%20ARPANET%2C%20the%20predecessor%20to%20the%20Internet.>]
Frank Heart's time at MIT Lincoln Laboratory:
* He initially worked on the Whirlwind computer project at MIT before
it was transferred to Lincoln Laboratory in 1953. [1
<https://historyofcomputercommunications.info/interviews/Frank-Heart/>]
* At Lincoln Lab, he worked on the SAGE (Semi-Automatic Ground
Environment) air defense system, which involved connecting computers
to real-time data sources and radar systems. [1
<https://historyofcomputercommunications.info/interviews/Frank-Heart/>,
2 <https://www.computerhistory.org/collections/catalog/102702094>, 4
<https://www.internethalloffame.org/2018/06/26/remembering-frank-heart-1929-2018/#:~:text=Later%2C%20Whirlwind%20came%20under%20the%20aegis%20of,and%20Newman%2C%20where%20he%20built%20first%20I.M.P.s.>]
* SAGE was a massive project aimed at creating a continental air
defense system using computers to process radar data and coordinate
interception of enemy aircraft. [1
<https://historyofcomputercommunications.info/interviews/Frank-Heart/>,
5
<https://historyofcomputercommunications.info/section/2.17/Real-Time-Computing-The-SAGE-Project-1952-1958/>]
* He collaborated with other notable figures in the field, including
Wes Clark, Larry Roberts, and Ivan Sutherland. [1
<https://historyofcomputercommunications.info/interviews/Frank-Heart/>]
* Heart's work at Lincoln Lab provided him with invaluable experience
in real-time computing and computer communications. [1
<https://historyofcomputercommunications.info/interviews/Frank-Heart/>,
2 <https://www.computerhistory.org/collections/catalog/102702094>]
Transition to Bolt, Beranek and Newman (BBN):
* In 1966, Heart left Lincoln Laboratory to join BBN, where he was
recruited for his expertise in computer applications in healthcare.
[1
<https://historyofcomputercommunications.info/interviews/Frank-Heart/>,
2 <https://www.computerhistory.org/collections/catalog/102702094>]
* However, he soon became involved in the ARPANET project, leading the
team that developed the Interface Message Processor (IMP), the first
routing computer for the network. [2
<https://www.computerhistory.org/collections/catalog/102702094>, 3
<https://en.wikipedia.org/wiki/Frank_Heart#:~:text=Frank%20Evans%20Heart%20(May%2015%2C%201929%20%E2%80%93,the%20ARPANET%2C%20the%20predecessor%20to%20the%20Internet.>,
4
<https://www.internethalloffame.org/2018/06/26/remembering-frank-heart-1929-2018/#:~:text=Later%2C%20Whirlwind%20came%20under%20the%20aegis%20of,and%20Newman%2C%20where%20he%20built%20first%20I.M.P.s.>]
* The IMPs were crucial for connecting different computers and
networks, enabling the early stages of the internet. [3
<https://en.wikipedia.org/wiki/Frank_Heart#:~:text=Frank%20Evans%20Heart%20(May%2015%2C%201929%20%E2%80%93,the%20ARPANET%2C%20the%20predecessor%20to%20the%20Internet.>,
4
<https://www.internethalloffame.org/2018/06/26/remembering-frank-heart-1929-2018/#:~:text=Later%2C%20Whirlwind%20came%20under%20the%20aegis%20of,and%20Newman%2C%20where%20he%20built%20first%20I.M.P.s.>]
* Heart's work at BBN on the ARPANET played a pivotal role in the
development of the internet as we know it today. [3
<https://en.wikipedia.org/wiki/Frank_Heart#:~:text=Frank%20Evans%20Heart%20(May%2015%2C%201929%20%E2%80%93,the%20ARPANET%2C%20the%20predecessor%20to%20the%20Internet.>,
4
<https://www.internethalloffame.org/2018/06/26/remembering-frank-heart-1929-2018/#:~:text=Later%2C%20Whirlwind%20came%20under%20the%20aegis%20of,and%20Newman%2C%20where%20he%20built%20first%20I.M.P.s.>]
/AI responses may include mistakes./
[1] https://historyofcomputercommunications.info/interviews/Frank-Heart/
[2] https://www.computerhistory.org/collections/catalog/102702094
[3] https://en.wikipedia.org/wiki/Frank_Heart
<https://en.wikipedia.org/wiki/Frank_Heart#:~:text=Frank%20Evans%20Heart%20(May%2015%2C%201929%20%E2%80%93,the%20ARPANET%2C%20the%20predecessor%20to%20the%20Internet.>
[4]
https://www.internethalloffame.org/2018/06/26/remembering-frank-heart-1929-2018/
<https://www.internethalloffame.org/2018/06/26/remembering-frank-heart-1929-2018/#:~:text=Later%2C%20Whirlwind%20came%20under%20the%20aegis%20of,and%20Newman%2C%20where%20he%20built%20first%20I.M.P.s.>
[5]
https://historyofcomputercommunications.info/section/2.17/Real-Time-Computing-The-SAGE-Project-1952-1958/
On 8/16/25 11:38, Vint Cerf wrote:
> probably worth recalling SAGE - some have claimed it didn't work but
> it is pretty clear that data was transferred among hosts - but they
> were homogeneous.
>
> v
>
>
> On Sat, Aug 16, 2025 at 2:31 PM Jack Haverty via Internet-history
> <internet-history at elists.isoc.org> wrote:
>
> John's right - it would be more accurate to say that event was
> passing
> the first messages on the ARPANET.
>
> History tends to think of the ARPANET as the first experiment in
> packet
> switching. Opinions differ of course...
>
> But another important innovation was ARPANET's ability to
> interconnect
> different kinds of computers, from different manufacturers, with
> wildly
> different architectures of hardware and software. Prior to 1969,
> there
> were many computers interconnected by telephone circuits. But they
> were generally homogeneous environments, most of which were based
> on IBM
> computers and terminals.
>
> Most people on this list would probably not consider a "multidrop
> line"
> as a "network", but that was a common technique for connecting a
> bunch
> of machines together, using a single "multidrop" circuit daisy
> chained
> through the bunch. IIRC, protocols involved were things like HDLC
> and
> SDLC.
>
> I remember a job I had while a student at MIT circa 1968, which
> involved
> terminals in classrooms talking to mainframes at IBM in New York
> to run
> APL programs for thins like hydraulics analysis. My job was to
> get it
> all up and running and fix any problems when the students attacked.
> Phones (and modems) seemed especially attractive to students even in
> those days. What does this button do...???
>
> Re testing: Yes, BBN tested extensively before shipping boxes out
> to the
> field. Ben Barker was one of the hardware guys working on the IMP in
> 1969, and he was the engineer who travelled with the IMPs to
> California
> to set up those first two nodes. Back in 2012 Ben and I exchanged a
> bunch of emails about the early ARPANET days, as part of research
> for a
> patent battle where the IMP was to be prominent as evidence of
> "prior art".
>
> Here's a snippet of his recollections about "IMP 1" as BBN was
> preparing
> to ship it - from the guy who actually did the work:
>
> > Just before we were to ship IMP 1, we had a problem where the
> machines
> > would crash mysteriously about once per 24 hours. It was a
> weird crash,
> > with the PC pointing at a completely random place, typically in a
> chain of
> > non-executable locations in a data structure, with no way it
> could have
> > gotten there. The location before would have caused a crash,
> there
> were no
> > jumps to it (with or without indexing ior indirection). I
> concluded
> that it
> > had to be a race condition with the heavy use of the DMC
> channel. I went
> > through the Honeywell drawings of the 516 processor and found a
> place
> where
> > the timing looked too tight. I figured a way to patch it in the
> > processor. I rewired it less than 24 hours before scheduled
> ship. It
> > fixed the problem and the machine shipped on schedule. We had a
> heck
> of a
> > time convincing Honeywell that they had this fundamental design
> flaw
> in the
> > central timing chain of their machine, but they eventually were
> convinced
> > and made the change in their future machines.
> >
>
> So there was extensive testing before IMP 1 was shipped, including
> redesign of the hardware when necessary to catch a failure that only
> occurred in testing about once per day.
>
> I didn't join BBN until 1977, but I remember that there was still
> extensive testing of new releases of IMP hardware and software.
> Sometimes tests were run literally for months or more.
>
> Enjoy,
> /Jack Haverty
>
> On 8/16/25 10:16, John Day via Internet-history wrote:
> > The NPL network already existed and had for awhile, a couple of
> years but I will have to go look at sources to be exact.
> >
> > Of course, what this should say is the first messages exchanged
> on the ARPANET.
> >
> > I am sure BBN tested it before they delivered it, but I don’t
> remember now what Hafner says about that.
> >
> > Take care,
> > John
> >
> >> On Aug 16, 2025, at 12:41, Dave Crocker via
> Internet-history<internet-history at elists.isoc.org> wrote:
> >>
> >> My Facebook feed just delivered a tidbit from UCLA that begins:
> >>
> >> "In 1969, UCLA Professor Leonard Kleinrock directed the
> transmission
> >> of the first message between two networked computers..."
> >>
> >> I found myself wondering a bit about that characterization:
> >>
> >> 1. Didn't BBN do some inter-host packet exchanges, when testing the
> >> IMPs, before shipping them to UCLA and SRI? Wouldn't that have
> >> counted as the actual first?
> >> 2. There were other packet research projects, at the time, but
> I don't
> >> remember the details of timing of other 'WAN' and 'LAN' project.
> >> 1969 was early enough that it's entirely possible the others
> were
> >> later, but I'd be interested in hearing the details.
> >>
> >> I suspect the refinement of the UCLA statement would be:
> >>
> >> "In 1969, UCLA Professor Leonard Kleinrock directed the
> transmission
> >> of the first message between two networked computers
> >>
> >> --
> >> Dave Crocker
> >>
> >> Brandenburg InternetWorking
> >> bbiw.net <http://bbiw.net>
> >> bluesky: @dcrocker.bsky.social
> >> mast: @dcrocker at mastodon.social
> >> --
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> >> Internet-history at elists.isoc.org
> >> https://elists.isoc.org/mailman/listinfo/internet-history
> >> -
> >>
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>
> --
> Please send any postal/overnight deliveries to:
> Vint Cerf
> Google, LLC
> 1900 Reston Metro Plaza, 16th Floor
> Reston, VA 20190
> +1 (571) 213 1346
>
>
> until further notice
>
>
>
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