What is a Computer What is a Computer .ppt

Computer? What’s a computer?
Until the 1930s a “computer” was a
person who did mathematical
calculations.
This changed at least in part due to
World War II --
The US, Great Britain and Germany
all had active research into computer
technology.
Copyright © 2008 by Helene G. Kershner

Man vs. Machine
Albert Einstein said:
Computers are incredibly fast, accurate, and stupid:
Humans are incredibly slow, inaccurate and
brilliant;
Together they are powerful beyond imagination.1
--
Albert Einstein
www.quotiki.com

We have desktop
computers.
Like this system at
www.dell.com

We have laptop computers
Apple
Dell

There are full
computers that
weigh little.
 Sony Vaio
Others are built to be
essentially
indestructible.
 Panasonic
ToughBook


And there are supercomputers.
Cray Inc.
www.cray.com

The one laptop per child non-profit initiative!
“The mission of One Laptop per Child (OLPC) is to empower
the children of developing countries to learn by providing
one connected laptop to every school-age child.”
http://www.laptopgiving.org

 Much of what we own, use and do contains
computers.
 A computer on the “inside” of a device designed to
do something else is an embedded computer.

Cars –
 Antilock break systems
 All wheel drive system
 GPS systems
 Satellite radio
Garmin 750

 There are digital calculators

Computer? What’s a computer
 PDA – Personal Digital Assistant
Palm TX Handheld HP iPAQ Moble Blackberry 8703e
Messenger

 Music Machines
Centon MP3 Player PowerUp MP3 Player Alexa MP3/MP4
Player

 Music Machines -- iPods

Then there are computers in
 Deep Fryers
 Microwave Ovens
 Alarm Clocks
 Cameras
 Augmentative Communication Devices
(Talkers)
 Cash registers
 Gasoline pumps

And then there are cell phones? Or are these
PDAs, cameras, alarm clocks, time pieces and…
computers

Computers, Where did they come from?
Computer = Person
 Devices to assist people with their calculations
Mechanical Age
 5000 BC
Still in use in Asia
 1621
Slide rule – William Oughtred

Mechanical Devices
 1642 -- Blaise Pascal invented the first machine like
adding machine (added and subtracted)
 Used gears or wheels that were moved with a pointed object
 Legend – he built if for his father who was a tax collector and
spent lots of time and effort adding and subtracting

1673 -- Baron Gottried Wilhelm von Leibnitz
redesigned Pascal’s device so it could multiply and
divide.

Mechanical Devices
 1833 – Charles Babbage an eccentric British
mathematician and inventor created a mechanical
machine that would perform many of the functions of
modern computers
 It was never built. The precision required for the
gear systems was beyond the capabilities of the day.
 Using more modern Engineering
techniques his son was able to
create a model an prove that it
would work.

The Industrial Age – mid 1800s through early 1900s
 Agrarian world  Industrialization
 Farms  factories
 Cloth made by hand  textile industries (mechanical loom)
 Animal power  steam  internal combustion engine
 Gas lights  electic lights
 Herman Hollerith’s Tabulating machine
 Contest to calculate the 1900 census
 “Grandparent” company of IBM
 1888 – William Burroughs’ created & patented a paper
tape adding machine
 Burroughs Corp. moved from adding machines to computers in
1961.

Burroughs Adding Machines
Early Burroughs 1925 advertisement 1950 era Burroughs
adding machine adding machine
Photos found on eBay

Next major step: late 1930
What was happening in the world in the late 1930s?
 Great Britian
 COLOSSUS -- 1943
 Single Purpose Computer – code breaker
www.codesandciphers.org.uk/lorenz/colossus.htm

Computers, Great Ideas
 In 1936, mathematician Alan Turing theorized
that a general purpose computer could be built.
 Great Idea – He asked, what is computable? He
then suggested that “a task is computable if one
can specify a sequence of instructions which when
followed will result in the completion of the task.” *
 This was intended strictly as a mathematical idea.
This concept/thought experiment is known as a
Turing machine.
 In 1943, Turing helped the British government
develop COLOSSUS.
*plato.stanford.edu/entries/turing-machine/

Computers, Great Ideas
 In 1944, scientist John Von Neumann added
his talents to the ENIAC team.
 Great Idea -- Developed the concept of
storing a program in the computer’s memory,
rather part of it’s circuitry.
 This is called the stored program concept.
 Each program was a numeric code using binary
digits (0 or 1) (off or on).
 Both the program and the data could now be
stored in memory.
Kershner, Computer Literacy 3rd Ed.

Next major step: late 1930
What was happening in the world in the late 1930s?
Telephone switches vs Vacuum Tubes
Harvard/IBM – Howard Aikens Univ. of Pennsylvania- John Mauchly &
1943 Presper Eckert 1946
www-03.ibm.com/ibm/history/exhibits/markI/markI_intro.html en.wikipedia.org/wiki/ENIAC

History
Computer Generations
Each Generation notes a major change in
technology.
 First Generation (1951 – 1958)
 Vacuum tube technology
 Punched card or magnetic tape
 Machine language
 Magnetic core
 Second Generation (1959 – 1964)
 Great Idea -- Transistor
 Solid-state technology – no moving parts
 Punched card or magnetic tape
 Assembly language or higher level language
 Magnetic core

Vacuum Tubes Transistors

en.wikipedia.org/wiki/Vacuum_tubes Schindler, Kris

History
Computer Generations
 Third Generation (1965 – early 1970s)
 Great Idea -- Integrated circuits (IC) – multiple
transistors on a chip
 Silicon chips
 Large-scale integration
 Punched cards, magnetic tape, magnetic disks
 Magnetic core, some semiconductor memory
 Fourth Generation Computers (early 1970s – present?)
 Very large-scale integration (VLSI)
 Great Idea– Computer on a chip - Microprocessor chip
 Magnetic disks, floppy disks, flash/memory sticks
 Great Idea – High level programming language“ --user
friendly” software
 Semiconductor memory

Computers, Where did they come
from?
Integrated Circuits (IC) Very large-scale integrated
circuits (VLSI)
Schindler, Kris

What is a Computer What is a Computer .ppt

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