Computer History

Computer HistoryComputer History

CS 110CS 110Fall 2005Fall 2005

HomeworkHomework TA Office hours TA Office hours

• Sunday, Sept 4Sunday, Sept 4thth from 3-5 from 3-5• Thornton Hall Stacks Computer LabThornton Hall Stacks Computer Lab

Review of HTML / HomedirReview of HTML / Homedir Connect using HomedirConnect using Homedir Explain the parallel between public_html on Homedir (as observed using Explain the parallel between public_html on Homedir (as observed using

Windows Explorer) and www.people.virginia.edu (as observed using Windows Explorer) and www.people.virginia.edu (as observed using Internet Explorer)Internet Explorer)

Visit http://www.people.virginia.edu/~dcb8jVisit http://www.people.virginia.edu/~dcb8j• This page is found in my public_html folderThis page is found in my public_html folder• Note the default is to display index.htmNote the default is to display index.htm

Demonstrate IP/URL parallelsDemonstrate IP/URL parallels• http://http://128.143.22.98/~dcb8j• To find IP address, use http://www.dnsstuff.com/To find IP address, use http://www.dnsstuff.com/

Demonstrate subdirectoriesDemonstrate subdirectories• http://www.people.virginia.edu/~dcb8j/Daughterhttp://www.people.virginia.edu/~dcb8j/Daughter• Note the link to an image (Rotunda) on the webNote the link to an image (Rotunda) on the web

Demonstrate access to specific web page (not default index.htm) Demonstrate access to specific web page (not default index.htm) • http://www.people.virginia.edu/~dcb8j/Daughter/keene2.htmhttp://www.people.virginia.edu/~dcb8j/Daughter/keene2.htm• Note the reference to an image stored in a folder other than the folder in which 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)the web page is found (“..” indicates the image is found in the parent folder)

http://128.143.22.98/

What is a computer?What is a computer?

Babbage’s “Difference Engine” for computing polynomials (1822)http://en.wikipedia.org/wiki/Difference_engine

Mechanical CalculatorsMechanical Calculators 1623 – first mechanical calculators1623 – first mechanical calculators

• Add, subtract, multiply, divideAdd, subtract, multiply, divide

1800s – computers that are powered 1800s – computers that are powered by steam and programmed by punch by steam and programmed by punch cardscards• Babbage and Ada Lovelace (Lord Babbage and Ada Lovelace (Lord

Byron’s daughter)Byron’s daughter)• IBM’s roots in 1890 censusIBM’s roots in 1890 census

Analog ComputersAnalog Computers 1900s - use a 1900s - use a

continuouslycontinuouslyvariable physicalvariable physicalquantity to storequantity to storevaluesvalues

Require “plumbing”Require “plumbing”to be adapted to to be adapted to new problemsnew problems

The Soviet Water Integrator (1936)

http://en.wikipedia.org/wiki/

Digital ComputersDigital Computers 1940s – WW II1940s – WW II

• Electronic circuits, vacuum tubes, etc.Electronic circuits, vacuum tubes, etc.• Mercury tube and TV tube memoryMercury tube and TV tube memory• Computer control over telephone linesComputer control over telephone lines

Parallel developments in Germany, Parallel developments in Germany, England, and the USEngland, and the US

The British War EffortThe British War Effort ColossusColossus

• Crack German Crack German encryption codesencryption codes

• Made NormandyMade Normandya successa success(18,000 messages(18,000 messagesper day)per day)

• Churchill ordered it to be destroyedChurchill ordered it to be destroyed“in pieces no larger than a man’s hand”“in pieces no larger than a man’s hand”

Colossus (1944)

http://en.wikipedia.org/wiki/Image:Colossus.jpg

Alan TuringAlan Turing

The creator of ColossusThe creator of Colossus The father of modern computer scienceThe father of modern computer science The inventor of the Turing TestThe inventor of the Turing Test The discoverer of computability through The discoverer of computability through

the Turing Machinethe Turing Machine

““Outed” as a homosexual in 1952 andOuted” as a homosexual in 1952 andforced to undergo hormone therapyforced to undergo hormone therapy

Committed suicide in 1954Committed suicide in 1954

The US War EffortThe US War Effort ENIACENIAC

• Used for Army ballisticsUsed for Army ballistics

The first computer known to beThe first computer known to becompletely completely generalizablegeneralizable(Turing Complete)(Turing Complete)

The German War EffortThe German War Effort ZuseZuse

• Turing-Complete computerTuring-Complete computer• Switched numeric representation from Switched numeric representation from

decimal system to binarydecimal system to binary• Utilized Von Neumann architecture Utilized Von Neumann architecture

where program is stored in same place where program is stored in same place as dataas data

• First high-level programming languageFirst high-level programming language

TransistorsTransistors 1947 – Bell Labs1947 – Bell Labs Electronic switchesElectronic switches On the same order as printing press On the same order as printing press

and the telephoneand the telephone Present in nearlyPresent in nearly

*all* electronic*all* electronicdevicesdevices

Desktop computersDesktop computerswere possiblewere possible

Integrated CircuitsIntegrated Circuits 1956 –Texas Instruments and 1956 –Texas Instruments and

Fairchild SemiconductorFairchild Semiconductor Layers of semiconductorsLayers of semiconductors

permit complex lattices ofpermit complex lattices ofdigital switchesdigital switches

Semiconductors changeSemiconductors changeconductivity in responseconductivity in responseto light (CCDs) or to light (CCDs) or electricity (ICs)electricity (ICs)

1960 - 19801960 - 1980 Things moved quicklyThings moved quickly Mainframe computer designs were Mainframe computer designs were

adapted to the new hardwareadapted to the new hardware New uses for computers were New uses for computers were

discovered (supercomputers)discovered (supercomputers) Simplicity and affordability made Simplicity and affordability made

computing available for home usecomputing available for home use

Home ComputersHome Computers 1974 – Intel 8080 IC1974 – Intel 8080 IC 1975 – Altair is first mass-produced1975 – Altair is first mass-produced 1977 – Apple II1977 – Apple II 1981 – IBM PC1981 – IBM PC 1982 – Commodore 641982 – Commodore 64

Specs: 64,000 bytes of RAM Specs: 64,000 bytes of RAM (vs 1 trillion)(vs 1 trillion)5,000 Hz 5,000 Hz (vs 4,000,000 Hz)(vs 4,000,000 Hz)

Commodore 64 (1944)

Home ComputersHome Computers Critical featuresCritical features

• Operating SystemsOperating Systems CP/M CP/M Microsoft copied to create MS-DOS Microsoft copied to create MS-DOS

• Kill AppsKill Apps MacWrite and MacPaintMacWrite and MacPaint

People started to need computersPeople started to need computers

Home ComputersHome Computers Graphical User Interface (GUI)Graphical User Interface (GUI)

• Apple Lisa (1983)Apple Lisa (1983)• Apple Macintosh (1984 Superbowl)Apple Macintosh (1984 Superbowl)• Microsoft Windows (1985)Microsoft Windows (1985)

The FutureThe Future The number of The number of

transistors transistors incorporated in a incorporated in a chip will chip will approximately approximately double every 24 double every 24 monthsmonths

Gordan Moore’s Law, 1965

ftp://download.intel.com/museum/Moores_Law/Printed_Materials/Moores_Law_Poster_Ltr.pdfs.jpg

The FutureThe Future Graphics CardsGraphics Cards

• Surpassing Moore’s LawSurpassing Moore’s Law• Much faster than CPUs (Why?)Much faster than CPUs (Why?)• Frequently the most expensive part on a Frequently the most expensive part on a

computer (Why?)computer (Why?)• What are game consoles?What are game consoles?