Inside The Internet Notes
Lectures
Intro
- Dawn of Electronic Computing
- Pre-Internet COmmunication
- Research networks 60s&70x
- The first "Internet" Mid 80s
- The Web early 90s
- Ubiquity of the internet mid 90s on
WWII
- 10,000 people working at Bletchley Park
- BOMBE: Mechanical computer
- Colossus: Electronic computer
Alan Turing and Bletchley Park
Bletchley park is considered the birthplace of modern computing. The day after war was declared several people (including Turing) showed up as had been arranged before the war. First Skunk Works operation. They brought the smartest people in Britan together with a nearly unlimited budget. Bletchly existed primarily to break the Enigma encryption. This was important to intercepting communications from the Blitz Kreig. Polish Mathematicians starting breaking the code. Bletchley built on their work. The polish computer was Bomba, the britsh was Bombe. Turing built "cribbing" into the Bombe so they could guess some text. Each Bombe simulate 36 enigma machines. There is between 10 and 12 miles of wire in each Bombe. Enigma was only good for short messages up to about 250 characters. The Geheimschreibers - "Secret Writers" were far more complex and could send long messages. The Mark I Colossus was designed to break this computer and went into operation in early 1944. Mark II was delivered before D-Day and was used to confirm that the deception surrounding D-Day worked. The Mark I Colossus used over 8Kw of electricity. Much of the design of Mark I was based of research done for the British Post Office. The machines were left on 24/7 as to not subject the vacuum tubes to thermal shock. The Colossus was rebuilt starting in 1993 by Tony Sale. Turing was not involved in Colossus.
History Through Modems and Terminnals
After the war there was a proliferation of electronic computing. Governments valued their mathematicians, scientists and engineers. Communication was initially done over telephone using teletype. Many early systems used tones sent over phone lines.
Leased Lines: Lines leased from telcos for full time access.
Store and Forward Network: Local computers or terminals would talk to a central computer with a leased line that would forward on to other computers in the network. Networks with more hops were slower but cheaper. As a result there was a movement to bring lots of Universities into the network. This was the early 80s, email took 6 hours to 2 days to cross the country. On of the first big networks of this type was Bitnet.