[ih] Nit-picking an origin story

[Vint Cerf]

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
> >> bluesky: @dcrocker.bsky.social
> >> mast: @dcrocker at mastodon.social
> >> --
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