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

Karl Auerbach karl at iwl.com
Mon Jun 1 12:18:10 PDT 2026


On 6/1/26 11:41 AM, Jack Haverty via Internet-history wrote:

>
> Where did those folks in the Computer Club go after leaving UCLA...?  
> Any of them in ROTC? 

Well, I suspect that some of us ended up getting drafted into the 
military.  (I almost was.)

Many of us ended up at Rand or SDC - only a few miles west of UCLA.

Regarding the story of the Plurebus ... at SDC I was part of the 
research group for operating system and network security.  We deeply 
explored capability architectures.  Such architectures are good not only 
for security but also for isolating and limiting the impact of both 
hardware failures and software errors.  One of our Plessy machines - a 
machine intended for use in a telco switching environment - was 
architected to have no more than ten minutes of downtime over a forty 
year span - including down time due to software errors.  (I got to 
design the hardware for a capability machine to run Peter Neumann's 
PSOS  - Provably Secure Operating System - we had to make significant 
architectural changes PSOS to create a machine that actually would work, 
most particularly changing from capabilities with infinite lifetimes to 
capabilities that were finite and could be garbage collected - Peter and 
I carried on that debate for decades afterwords.  I think he may have 
conceded in CHERI architecture.)

For a while I was working at RSRE - Royal Signals and Radar 
Establishment - in Great Malvern, UK.  (Sometimes when I had to do 
something in the Slough or Maidenhead facilities I got to work a little 
bit with Donald Davies.)

RSRE was an RAF facility - surprisingly, with a copy of Picasso's 
"Guernica" on the wall of the officer's mess hall.  I, being utterly 
naive about military ranks and procedures, did not realize that the 
typical rank of the people with whom I was working - all had masters or 
phd's - was colonel.  And I did not realize that colonel was a fairly 
serious rank that could bend rules.

So one afternoon - after our daily game of croquette after lunch - one 
of the RAF colonels said "You say that this machine is robust and will 
continue to run.  Hmmm, let me think upon this." He then pulled a hand 
grenade out of his kit and mimed pulling the pin and tossing it into the 
machine.  We conceded that that kind of thing was most likely beyond the 
survival abilities of the machine.

         --karl--




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