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Computer History. CS 110 Fall 2005. Homework. TA Office hours Sunday, Sept 4 th from 3-5 Thornton Hall Stacks Computer Lab. Review of HTML / Homedir. Connect using Homedir
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Computer History CS 110 Fall 2005
Homework • TA Office hours • Sunday, Sept 4th from 3-5 • Thornton Hall Stacks Computer Lab
Review of HTML / Homedir • Connect using Homedir • Explain the parallel between public_html on Homedir (as observed using Windows Explorer) and www.people.virginia.edu (as observed using Internet Explorer) • Visit http://www.people.virginia.edu/~dcb8j • This page is found in my public_html folder • Note the default is to display index.htm • Demonstrate IP/URL parallels • http://128.143.22.98/~dcb8j • To find IP address, use http://www.dnsstuff.com/ • Demonstrate subdirectories • http://www.people.virginia.edu/~dcb8j/Daughter • Note the link to an image (Rotunda) on the web • Demonstrate access to specific web page (not default index.htm) • http://www.people.virginia.edu/~dcb8j/Daughter/keene2.htm • Note the reference to an image stored in a folder other than the folder in which the web page is found (“..” indicates the image is found in the parent folder) http://128.143.22.98/
What is a computer? Babbage’s “Difference Engine” for computing polynomials (1822) http://en.wikipedia.org/wiki/Difference_engine
Mechanical Calculators • 1623 – first mechanical calculators • Add, subtract, multiply, divide • 1800s – computers that are powered by steam and programmed by punch cards • Babbage and Ada Lovelace (Lord Byron’s daughter) • IBM’s roots in 1890 census
Analog Computers • 1900s - use a continuouslyvariable physicalquantity to storevalues • Require “plumbing”to be adapted to new problems The Soviet Water Integrator (1936) http://en.wikipedia.org/wiki/
Digital Computers • 1940s – WW II • Electronic circuits, vacuum tubes, etc. • Mercury tube and TV tube memory • Computer control over telephone lines • Parallel developments in Germany, England, and the US
The British War Effort • Colossus • Crack German encryption codes • Made Normandya success(18,000 messagesper day) • Churchill ordered it to be destroyed“in pieces no larger than a man’s hand” Colossus (1944) http://en.wikipedia.org/wiki/Image:Colossus.jpg
Alan Turing • The creator of Colossus • The father of modern computer science • The inventor of the Turing Test • The discoverer of computability through the Turing Machine • “Outed” as a homosexual in 1952 andforced to undergo hormone therapy • Committed suicide in 1954
The US War Effort • ENIAC • Used for Army ballistics • The first computer known to becompletely generalizable(Turing Complete)
The German War Effort • Zuse • Turing-Complete computer • Switched numeric representation from decimal system to binary • Utilized Von Neumann architecture where program is stored in same place as data • First high-level programming language
Transistors • 1947 – Bell Labs • Electronic switches • On the same order as printing press and the telephone • Present in nearly*all* electronicdevices • Desktop computerswere possible
Integrated Circuits • 1956 –Texas Instruments and Fairchild Semiconductor • Layers of semiconductorspermit complex lattices ofdigital switches • Semiconductors changeconductivity in responseto light (CCDs) or electricity (ICs)
1960 - 1980 • Things moved quickly • Mainframe computer designs were adapted to the new hardware • New uses for computers were discovered (supercomputers) • Simplicity and affordability made computing available for home use
Home Computers • 1974 – Intel 8080 IC • 1975 – Altair is first mass-produced • 1977 – Apple II • 1981 – IBM PC • 1982 – Commodore 64 • Specs: 64,000 bytes of RAM (vs 1 trillion)5,000 Hz (vs 4,000,000 Hz) Commodore 64 (1944)
Home Computers • Critical features • Operating Systems • CP/M Microsoft copied to create MS-DOS • Kill Apps • MacWrite and MacPaint • People started to need computers
Home Computers • Graphical User Interface (GUI) • Apple Lisa (1983) • Apple Macintosh (1984 Superbowl) • Microsoft Windows (1985)
The Future • The number of transistors incorporated in a chip will approximately double every 24 months Gordan Moore’s Law, 1965 ftp://download.intel.com/museum/Moores_Law/Printed_Materials/Moores_Law_Poster_Ltr.pdfs.jpg
The Future • Graphics Cards • Surpassing Moore’s Law • Much faster than CPUs (Why?) • Frequently the most expensive part on a computer (Why?) • What are game consoles?