Juan Monroy — Week 2, Bits and Bytes

1 Bit
- 1.1 binary digit
- 1.2 fundamental building block of computing
- 1.3 expressed…
  - 1
  - 0
- 1.4 logical values
  - yes/no
  - true/false
  - +/-
  - on/off
2 Byte
- 2.1 basic unit of digital information
  - usually eight bits
- 2.2 basic meaningful computer unit
  - a letter of text
3 Storage
- 3.1 Magnetic Storage
  - magnetic tape
  - magnetic disks
- 3.2 Optical Storage
  - magento-optical drives
  - CD and DVD
4 Computer Processors
- 4.1 Diodes
  - vacuum tubes
  - Thomas Edison 1883
  - John Fleming 1904
  - Lee deForest 1912
- 4.2 Transistors
  - Texas Instruments 1947
  - Minicomputers
    - cabinet sized computers
- 4.3 Microprocessors
  - Intel 1971
  - microcomputers
5 Computers and the Military
- 5.1 electronic computer
  - John Vincent Atanasoff
  - World War II
  - deployed for military use
- 5.2 Colossus
  - British Secret Service
  - Alan Turing
  - crack Nazi codes
- 5.3 ENIAC
  - electronic numerical integrator and calculator
  - processed calculations for the hydrogen bomb
- 5.4 SAGE Air Defense
  - Wide Area Network (WAN)
  - modems
  - warned of coming Russian bombers
- 5.5 Livermore California atomic weapon lab
  - linked computers
  - local area network
6 Advanced Research Projects Agency
- 6.1 branch of Defense department
- 6.2 started in 1958 in response to Sputnik launching
- 6.3 cooperated with research universities
- 6.4 headed by J.C.R. Licklider
7 ARPANET
- 7.1 distributed network
  - computer network
  - decentralized
  - designed to survive nuclear attack
- 7.2 first connection
  - between UCLA and Stanford
  - November 1969
  - message: “login”
  - resulted in both computers crashing
- 7.3 first public demonstration in 1972
  - email communication
  - internetting: a network of networks
8 Technical Standards
- 8.1 “Esperanto for machines”
- 8.2 packet switching
  - Paul Baran
  - fundamental mode of communication for the Internet
- 8.3 TCP/IP
  - Vincent Cerf
- 8.4 Internet names and numbers
  - Jon Postel
- 8.5 electronic mail
  - Ray Tomlinson
9 Alto
- 9.1 Xerox PAC
- 9.2 first personal computer
- 9.3 1973
- 9.4 desktop metaphor
  - mouse
  - GUI
- 9.5 Ethernet
  - high-speed LAN
  - Bob Metcalfe
10 Altair 8800
- 10.1 microcomputer, 1975
- 10.2 mail order
- 10.3 Altair BASIC
  - written by Bill Gates
  - Microsoft’s first product
- 10.4 specs
  - Intel 8080 processor
  - 256 bytes
  - front panel with lights
  - $400 kit. assembled for $500.
- 10.5 Apple II
  - personal computer, 1977
  - Steve Jobs and Wozniak
- 10.6 Macintosh
  - 1984
  - graphic user interface
  - Hypercard
    - linking on keywords or icons
11 Prestel
- 11.1 1979
- 11.2 Great Britain
- 11.3 Videotex
  - TV set displays
  - text only
12 Bulletin Board Systems
- 12.1 exchange email
- 12.2 post opinions
- 12.3 upload and download information
13 Closed Networks
- 13.1 BITNET
  - email for university professors
- 13.2 USENET
  - discussion group system
14 NSFNet
- 14.1 National Science Foundation
- 14.2 1986
- 14.3 merged existing networks
15 Commercial Internet
- 15.1 NSF withdrew funding
- 15.2 opened network to commercial users in 1991
- 15.3 post Cold War
16 World Wide Web
- 16.1 Tim Berners-Lee
- 16.2 1991
- 16.3 hypertext markup language
- 16.4 World Wide Web
  - linked documents
  - transporting text documents across computer networks
17 Mosaic
- 17.1 Mark Anderseen
- 17.2 University of Illinois
- 17.3 first graphical world wide web browser
- 17.4 average computer user could browse the web
- 17.5 basis for Netscape (eventually Firefox)
18 Internet Boom
- 18.1 Netscape had 50 million users
- 18.2 America Online
- 18.3 Amazon.com
  - electronic bookstore
  - Jeff Bezos
- 18.4 eBay
  - online auction
- 18.5 Yahoo
  - Internet directory and portal
- 18.6 Google
  - search engine