.....Interface Message Processor ---.
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In late 1969, the small Cambridge, Mass.-based engineering and consulting firm of Bolt Beranek and Newman (BBN) was awarded a $1 million contract to build the ARPA network's first Interface Message Processor, or IMP. The BBN engineers assigned to the task dubbed themselves the IMP Guys. The computer-cum-communications switch was built around a Honeywell minicomputer called the DDP-516. The machine had a core memory, and its total memory was tkK. (Minicomputers, the generation of computer to follow room-sized mainframes, were approximately the size of large refrigerators.)
It took the IMP Guys nine months to finish
programming and debugging the machine. The first
IMPs were ruggedized, military style, suitable
for battle, with steel eye hooks at the top for
lifting them by crane onto the decks of naval
ships. IMP No. 1 was installed at UCLA on Labor
Day weekend in 1969. The second ARPANET node was
to be at Stanford Research Institute (now SRI),
and IMP No. 2 arrived there a month later. The
first communications over the ARPANET took place
a few days after the SRI installation, when the
host computer at UCLA logged onto the host
computer at SRI, using a crude form of remote
login.