Personal Computing & the Internet Workshop 2

Outline Personal Computers Software and User Interface Connectivity Altair 8800 Kit Apple II IBM PC Software and User Interface Smalltalk MacIntosh Windows Connectivity Arpanet Email World Wide Web Search Social Networking

Altair 8800 1974 In 1974 the Altair 8800 microcomputer kit was sold for about $400. It could be programmed in Altair Basic. Bill Gates talks about Microsoft and the Altair 8800 (1994 5 mins /\) TSS: Homebrew Computer Club (9 mins/\)

Apple II In 1977 Steve Wozniak introduced the Apple II for about $1,300. Legendary Founders - Steve Jobs & Steve Wozniak, Apple (17 mins /\) Apple II Review (4 mins /\) Steve Jobs: Man in the Machine (2015) (2 hours)

IBM PC 1981 This Day In History: August 12 - IBM Personal Computer Released (1981 1 min /\) Microsoft Founders, Paul Allen and Bill Gates IBM PCJr 1984

Smalltalk 1980 Adele Goldberg presenting Smalltalk-80 from Xerox PARC (3 mins/\) The Smalltalk-80 Programming System (1983 18 mins /\) Alan Kay Part 1 Talks about computer education (following Papert) (9 mins /\)

Macintosh Apple Macintosh (1984) 1979 Steve Jobs visits Xerox PARC Screens had bitmapped graphics User interface was intuitive Desktop metaphor Icons representing documents Folders for file directories Mouse for clicking and dragging Steve Jobs presenting the first Mac in 1984 (5 mins fuzzy) Macintosh 1984 Promotional Video - with Bill Gates! (3 mins /\)

Windows 1985 Microsoft released Windows I (shoddy) Steve Jobs to Bill Gates “You’re ripping us off! I trusted you and now you’re stealing from us!” Gates to Jobs: “Well, Steve, I think there’s more than one way of looking at it. I think it’s more like we both had this rich neighbor named Xerox and I broke into his house to steal the TV set and found out that you had already stolen it.”

Intergalactic computer network 1962 J. C. R. Licklider conceived a global computer network at Bolt, Beranek and Newman Goal: Allow computers to communicate Different locations Different operating systems Different programming languages

Origins of the Internet – The Arpanet ARPA (Advanced Research Projects Agency) supported research at diverse campuses The projects required extensive computer resources The computers systems differed and could not communicate with each other Research was often duplicated Nuclear annihilation threat With communications down countries could not respond in a measured way This favored pre-emptive attack Robust communications would give more time for a deliberate response ARPAnet - the team behind the internet (6 mins /\)

Network topology The balls are nodes (computers) The lines are links (wires) Which topologies have a single point of failure? (node or link) Which topology is most likely to survive an attack?

Packet Switching Goal: Remove need for a dedicated circuit                    Packet Switching Goal: Remove need for a dedicated circuit Messages broken into small packets Packet headers contain addressing + meta information Packets may be routed differently to balance network traffic At destination message is reassembled Missing or damaged packets are resent Developed independently by Paul Baran at the RAND Corporation and Donald Davies in the UK

Standards and Protocols for Network Communication 1983 OSI Reference Model as published International protocol to enable communication How does a packet travel the network? by Susana Rios (3 mins /\) Understanding the OSI Reference Model (10 mins – gets technical /\) High Tech Heroes #32: Paul Baran (28 mins /\)

Why the Web Works Jonathan Zittrain: The Web as random acts of kindness (20 mins)

Email 1971 Ray Tomlinson at BBN developed a way to send electronic mail to a user on another computer. He invented use of “@” to address the target computer. ~1975 Distribution lists created, i.e. SF- Lovers. Raymond Tomlinson, Who Put the @ Sign in Email, Is Dead at 74

The World Wide Web From The Guardian Tim Berners-Lee - Uniform resource Locator (URL) used to address a document on a remote computer. HTML (Hypertext Markup Language) used to describe a page in a web browser including embedded links, URLs to documents. Tim Berners-Lee: The next Web of open, linked data (17 mins /\) Marc Andreessen On The Internet's Early Days – Talks about developing MOSAIC browser at Univ. Of Illinois (4 mins /\)

Search Engines Alta Vista Launched 1995 created by DEC, subsumed into YAHOO and shut down in 2013 Alta Vista ad featuring Garry Kasparov (1 min /\) Terry Winograd Thesis advisor Seymour Papert Spcialty: human-computer interaction HCI At Stanford had students Larry Page & Sergei Brin How Search Engines Work (6 mins /\) Chart showing How Google Works

PageRank Algorithm A web search scores many hits They are arranged in descending order of importance By an algorithm named for Larry Page?? A page’s rank is largely determined by links into it from other pages Links in from major sites such as on-line newspapers count more Links out from a page also count a bit Most users do not look beyond the first page or two of results From Wikipedia. Mathematical PageRanks for a simple network, expressed as percentages. Page C has a higher PageRank than Page E, even though there are fewer links to C; the one link to C comes from an important page and hence is of high value.

Social Networking 2003 MySpace 2004 Facebook The Illustrated Story of Facebook (2 mins /\) Mark Zuckerberg : How to Build the Future (25 mins) Sherry Turkle: Connected, but alone? | TED Talk (20 mins)