©
Mark Ollig
Feb.
7, 1958, the seeds of the internet took root when the Department of Defense
Directive 5105.15 activated the Advanced Research Projects Agency (ARPA).
Four
months earlier, the Soviet Union launched a missile containing Sputnik 1, the
world’s first artificial satellite to orbit the Earth.
Sputnik
1 caused fear and anxiety among those worried the next Soviet missile orbiting
above the US might release a nuclear warhead instead of a harmless beeping
satellite.
It
was the late 1950s. The Cold War was at its height. The possible destruction of
the US military’s core computer system in a single attack pushed into action
the creation of a brand-new computer communications network.
To
ensure military computers would be accessible in the event of a nuclear attack,
ARPA designed a survivable computer communications network named ARPANET.
This
network used data-packet-switching protocol transmissions over dedicated
long-distance telephone lines for sharing resources from
geographically-separated computers across the country.
ARPANET
would provide redundant connection paths from military computers connected on
its network to the remote teletype data terminals used by military personal.
It
was instrumental in laying the groundwork for the “network of networks,” known
today as the internet.
The
first attempt at a host-to-host message between different model computers using
the ARPANET happened Oct. 29, 1969.
A
Scientific Data Systems (SDS) Sigma-7 32-bit host computer node located in 3420
Boelter Hall at the University of California, Los Angeles (UCLA), was linked
over dedicated telephone line facilities network to a second computer node, an
SDS-940 time-sharing host computer located 350 miles south at the Stanford
Research Institute (SRI) in Menlo Park, CA.
A
small cable from the Sigma-7 computer terminates into an Interface Message
Processor (IMP).
The
IMP uses serial-communication messaging protocols to send/receive data packets
over the ARPANET and into the SDS-940 computer’s IMP.
An
IMP is essentially an internet router used for connecting computing devices
over networks, and for delivering packets of digital data.
The
IMP used in 1969 is the size of a refrigerator.
The
telephone lines served as the physical transport facilities to the second node
in this network, the SRI host computer, which connected to its own IMP.
The
ARPANET transport facilities functioned as the “internet” between the two IMPs.
Charley
Kline, a programmer and student at UCLA, was attempting to send the login
command, “LOG” to the SRI SDS-940 from his teletype terminal connected to the
Sigma-7.
“I
would type a character. It would go into my computer. My software would take
it; wrap around it all the necessary software to send it to the IMP. The IMP
would take it and say, ‘Oh, this is supposed to go up to SRI,’” Kline explained
during a 2009 National Public Radio interview.
Kline
typed the letters “L” and “O” from his teletype terminal. The Sigma-7 computer
transmitted this data to the SRI SDS-940 computer over the ARPANET link
connecting the two machines.
During
this time, Kline was on the telephone with Bill Duvall, another programmer,
operating the SDS-940 computer at the SRI.
Duvall
confirmed to Kline the SDS-940 computer received and recognized his typed
characters “L” and “O.”
However,
a problem occurred when Kline typed in the final letter, “G.”
The
SDS-940 computer did not receive the “G.”
At
SRI, Duvall discovered a memory buffer became full, causing the SDS-940 to stop
working. In other words, it crashed.
And
so, the first official word successfully transmitted over the original internet
was “LO.”
So,
“lo” and behold, we have a problem with the login.
Meanwhile,
Duvall understood the circumstances causing the computer crash and knew how to
correct it from happening again.
He
needed to increase the size of a memory buffer on the SRI SDS-940 computer,
which took about an hour to complete.
Once
Duval completed the memory modifications, he asked Kline to retype the login
command.
Kline
typed “L-O-G” from his terminal at UCLA.
This
time, the three-letter word was successfully recognized as a login command by
the SDS-940 computer at the Stanford Research Institute.
The
SDS-940 automatically filled-in the “I-N” to complete the “L-O-G-I-N” command.
Kline
was now remotely logged into the SDS-940.
He
was able to type computing commands from his remote terminal into the SDS-940
and confirm the results.
The
SDS Sigma-7 terminal in Los Angeles was operating as a teletype terminal
directly connected to the SDS-940 computer in Menlo Park.
This
type of data communication exchange is known as a telnet session.
The
importance of Kline’s and Duvall’s work meant no longer needing a collection of
uniquely programmed and designed teletype/computer terminals only compatible
with specific models of computers requiring dedicated connections.
Now,
a user with one computer terminal can (with proper clearance) connect, log in,
perform commands, and access information from different models of computers
connected on the internet.
Kline’s
logbook shows the first message sent over the newly-born internet took place
Oct. 29, 1969 at 10:30 p.m. His handwritten note is here:
https://bit.ly/2Vh1pYo.
With
new college and university computer nodes added, the expansion of the internet
was well underway.
A
photo of an Interface Message Processor is at https://bit.ly/2WnDovk.
The
ARPANET diagram with the UCLA and SRI computer nodes can be viewed here:
https://bit.ly/2V45E4w.
See
the Department of Defense Directive 5105.15 at https://bit.ly/2pLunRy.
Tuesday
is the recognized 50th birthday of the internet, so celebrate accordingly.
