CS 197Computers in Society

History of Computing

The Wiki

How is everyone doing?Photo time!I'll place these in my shared folder so

you can upload them into the wiki.Teams. Who is on which team???I want each team to have a name, a

logo, and a wiki page by Thursday.

Reading for Thursday

The reading assignment will be just for the news article.

You'll see the it posted in the wiki and on the bulletin board in front of class.

Your are responsible for both the article and background research needed to be able to understand it.

Comprehensive links from the wiki will help you.

I suggest you do the reading with your homework team.

News Presentations

* Always at the start of class* Public is invited* All supporting material is due the

Tuesday before the presentation\* You need to do a lot of reading to be

ready for discussion of your presentation! Everyone has to have read the article but you need to go beyond it.

Presentation Materials* Wiki page including the link to the article, a nice

graphic, a brief summary, links to background material, a set of at least 4 quotes (not just from the article – background material is good), and at least 3 discussion points.

* Poster (Powerpoint) that we can post on the board outside class – reuse the material above. Must have a graphic and all discussion points.

* A printout of the article done nicely (Powerpoint)* Slides for in class (all that’s in the wiki + anything

else you want to add), Powerpoint. This is attached to the wiki page.

I must approve your article before your do all this!

Presentations

I want to get all presentations on the calendar soon. Pick dates for your presentations and wiki them into the calendar.

I need a team to present a news article next week.

Predicting the Future

OK – so Vannevar Bush didn't get everything right but he did see some of the core issues that would come up in the future.

What other sorts of futurism are you aware of? Give some examples!

A Tour of The Computer

* Processing* Memory* Transmission* Interfacing with the real world

It is important to understand how we assess these things! What makes one device better than another?

The Computing Element

John Von Neumann, one of the pioneers of computing, used the word “Organ” to describe these elements. The biological metaphors started from day 1 …

The original computing element was the human brain. But eventually mechanical devices were created to speed up the calculation process.The apex of mechanical computing was Babbage’s “analytical engine”, a device too complex to ever work.This early computing was mathematical – building tables of numbers for navigation and engineering purposes.

Historical Computing Devices

Electronic Computing

The big innovation in computing was the replacement of mechanical computing devices by purely electronic ones.

A gear or relay is too big / slow / unreliable to use in large quantities.

An electronic switch has no moving parts – it operates by pushing electrons around.

The original electronic computers used vacuum tubes – later transistors took over.

Electronic GatesA gate is a device in which one signal

controls another. In a vacuum tube, the grid could block or allow flow from input to output. So this is just like a relay.

Transistors are very similar – just a lot smaller.

SiliconThe “computer revolution”

came about when VLSI technology allowed a single chip to contain LOTS of transistors. A Pentium has about 50 million transistors. That would have been a lot of vacuum tubes. Manufacturing cost is something like $0.000001 per transistor.

Timeline

• 2500BC – 300BC: Abacus• 1617: Napier’s Bones• 1820: First mass-produced mechanical

calculators• 1822: Babbage’s difference engine• 1930: motorized mechanical calculators

able to quickly add, subtract, multiply, divide

• 1940s: digital computers (vacuum tubes)

Timeline

• 1950s: computers are mass produced and become common in the business world

• 1960s: transistors give way to integrated circuits

• 1980s: personal computing arrives• Now: a typical computer can do 5 –

10 million numeric calculations per second (MFLOP)

Assessing Computation

How can we assess a computational technology?

This turns out to be REALLY HARD! Knowing how fast a device can do one task doesn’t tell us a lot about other tasks.

Approaches:• Clock rate (not very accurate)• MFLOP (only helps for numeric calculations)• Specific benchmarksUnits: tasks / second

Information Storage

Storing information is as important as processing it.This all started with written language:

Important ideas:• Precise relationship between spoken and written languages• Ability to make a “perfect copy” of a document• A medium (clay, paper, …) is used to preserve information over time

Organizing Information

Given a large collection of information, how do we find what we need?

• Alphabetical ordering• Dewey Decimal System• Indices

Long before google, people needed to find things in information collections.