[ih] A small story of IMP #1 and the UCLA Computer Club

[Craig Partridge]

By the time I joined BBN, the story was that the person shooting the
Pluribus had been forced to write programs for it.  It had a BBN-wide
reputation for not being programmer-friendly (which is saying something, as
BBN periodically generated computing platforms which were painful to
program -- such as the C70 with 10-bit bytes).

Craig

On Mon, Jun 1, 2026 at 12:41 PM Jack Haverty via Internet-history <
internet-history at elists.isoc.org> wrote:

> Another IMP story...
>
> The "Pluribus" computer was a BBN creation that included highly
> redundant hardware, with multiple everythings.   The idea was that no
> matter what failed, the system would keep running while repairs were
> made.  Of course a Pluribus could be used as an IMP, which was popular
> in some government installations.  One day at BBN, I heard this story.
> Wasn't there myself, but I can believe it.
>
> A Pluribus IMP was being decommissioned at some government site.  They
> happened to have a variety of military stuff around.   So someone
> decided to see if the Pluribus IMP was as reliable as it was touted to be.
>
> The IMP was set up, still running.   Someone got a rifle (M-16?) and
> started shooting at the IMP.  Really.  Sadly I don't recall the number,
> but the IMP survived an amazing number of direct hits at point blank
> range, and still kept passing traffic.
>
> Where did those folks in the Computer Club go after leaving UCLA...?
> Any of them in ROTC?
>
> /Jack
>
> On 6/1/26 11:22, Karl Auerbach via Internet-history wrote:
> > This is a trivial, and quite irreverent, bit of Internet history....
> >
> > I, like several others, were members of the UCLA computer club during
> > the late 1960's.  The club's office was in Boelter Hall - not far from
> > the room that held IMP #1 (and the Sigma computer - along with its
> > "Sigma EXecutive" documentation, aka "SEX Manuals".  My project's
> > computer, an IBM 7094 - with a true memory leak [the core memory was
> > oil cooled, and that oil leaked] - was in the next room over and we
> > could hear the squeals from the AM radio caused by the RF noise from
> > the IMP and the Sigma.)
> >
> > Anyway, folks in the Computer Club - especially Mark Kampe - kinda
> > like to pull pranks.  For instance, we would drop things from the top
> > of Boelter Hall (9 floors up) to see what would happen.  The landing
> > zone was the collection of crunched and bent automobiles resulting
> > from the early crash-tests of my group, the Institute of Traffic and
> > Traffic Engineering.  We dropped everything from frozen superballs to
> > a lead container used to hold/transport radioactive materials [it was
> > empty].  There was also a feisty ice-cream vending machine in the
> > hallway that once-too-often failed to deliver the paid-for frozen
> > treat - so someone in the club unplugged the machine for a few hours,
> > everything inside melted, and then plugged it back in, re-frezzing the
> > leaking drippy mess.  That was not nice, but it was - here's a
> > terrible pun - that vending machine received its just desserts.
> >
> > Anyway, back to Internet History...
> >
> > IMP #1 had the rough appearance of an armor plated refrigerator, with
> > lifting lugs on the top.  The machine was "ruggedized".
> >
> > That word, ruggedized, was like honey to ants - it seriously caught
> > our attention.  So we (I think Mark K. in particular) asked "Is it
> > rugged enough to survive a drop from the top of Boelter Hall?".
> >
> > So our imaginations lit up with images of us grabbing IMP #1, hauling
> > it up to the roof and dropping it into the crashed cars nine floors
> > below.
> >
> > Obviously, prudence and sanity - and perhaps even some, probably
> > reluctant, respect for law - prevailed.  We never did get beyond the
> > "what if we did this" stage.
> >
> > (But a couple of years later some of us migrated from UCLA to SDC in
> > Santa Monica.  At SDC we had an extremely awful HP 2000 minicomputer
> > that, if I remember properly, did actually suffer such a fate as it
> > was dropped it from the roof of the Q7A building - three stories tall
> > - onto the parking lot - a fate that all of us applauded. [It was
> > truly a terrible machine with an even worse operating system.]  Some
> > of use, years later, moved onto the Interop show nets were we sometime
> > had to practice the delicate art of percussive maintenance.)
> >
> >         --karl--
> >
>
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