Computers in Society

History of Computing

Homework

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Futurism

Can we understand the future of computing?

What sort of predictions have been made?

Looking Back to Look Ahead

Perhaps the best way to look into the future of computing is to look back.

Many predictions have been made – in books, in movies, by academics, by entertainers, by companies. Most of these predictions have been very wrong!

What are some examples of “serious” predictions about the future of computing?

Dubious Quotes"Everything that can be invented has been invented."

— Charles H. Duell, Commissioner, U.S. Office of Patents, 1899. "Computers in the future may weigh no more than 1.5 tons."

— Popular Mechanics, 1949 "I have traveled the length and breadth of this country and talked with the best people,

and I can assure you that data processing is a fad that won't last out the year." — The editor in charge of business books for Prentice Hall, 1957.

"There is no reason anyone would want a computer in their home." — Ken Olson, president of Digital Equipment Corp., 1977.

"640K (of memory) ought to be enough for anybody." — Bill Gates, 1981.

"If the automobile had followed the same development cycle as the computer, a Rolls-Royce would today cost $100, get a million miles per gallon, and explode once a year, killing everyone inside." — Robert X. Cringely, InfoWorld

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. Note that computers are built from a single part!

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