History of Computing

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					History of Computing

The original need for
computers and other devices…

--- to serve as counting machines

          The real early years…

   An abacus, developed by the
    Babylonians @300 BC is a
    calculating tool for performing
    arithmetic processes. The
    abacus was in use centuries
    before the adoption of the
    written modern numeral
    system and is still widely used
    by merchants and clerks in
    China, Japan, Africa, India and

More on the abacus…

   A modern abacus consists of rings that
    slide over rods, but original ones used
    pebbles (the word ―calculus‖ comes
    from the Latin word for pebble)

        Other Early Attempts…         (da Vinci)

   Leonado da Vinci (1452-1519)
    made drawings of gear-driven
    calculating machines but
    apparently never built any.
   Da Vinci known as a painter &
    sculptor – but also was an
    architect, engineer, and
   His contributions to mechanical
    calculation remained hidden
    until the rediscovery of two of
    his notebooks in 1967.

     Other Early Attempts…                         (Schickard)

1623 -- Wilhelm Schickard
  designed a machine
  called “the Speeding
  Clock” for calculating
  astronomical tables. It
  could add and subtract
  up to 6-digit numbers.

 (got little publicity – Schickard died soon afterward in the
                         bubonic plague)
         Other Early Attempts…(Pascal)
   1642 -- Blaise Pascal made a
    mechanical calculator called the
    Pascaline – could add and subtract
    to help his father – a tax
    collector (wasn’t very accurate –
    gears couldn’t be made with the
    required precision)
   Until car odometers went digital, they used the
    same mechanism as the Pascaline to increment
                 Have you ever heard of ―Pascal‖?
        Other Early Attempts …                    (Leibniz)

   Baron Gottfried Wilhelm von Leibniz:
       1672 -- Made a 4-function mechanical
        calculator called the ―Stepped Reckoner‖
       Still – reliability of results was an issue…

           What do you think those 4 functions were?
         Other Early Attempts…       (Leibniz)

   Leibniz also introduced
    concept of Base 2
    (binary) number system
    -- In this system, all numbers
    are represented using only
    two symbols – 0 and 1

        Other Early Attempts…                       (Boole)

   1854 -- George Boole published an algebra based
    on this Base 2 system called ―Boolean algebra‖.
   Boolean Algebra:
       Based on Leibniz’s concept of using 0’s and 1’s:
            No-yes,
            False-true,
            Off-on
   Took around 30 years before its potential use in
    electrical logic circuits was realized.
   Was instrumental in the design of digital electronic
    circuitry (still used today for that purpose)
       0 = off and 1 = on
          Practical uses of math in the early 1800’s..
   Anyone needing results of
    complicated calculations relied on
    printed numeric tables
      Engineers, architects,
       astronomers, navigators, etc
   Printed numeric tables were
    generated by mathematicians by
   Tedious and prone to error

   An example: the British Gov’t
    published a 7-vol set of navigation
    tables (which came with another huge volume containing
    corrections (over 1000 numerical errors!!!)
       Other Early Attempts …             (Babbage)

   Charles Babbage (a mathematician & inventor) got
    quite frustrated trying to use these error-
    laden tables and decided to build a machine that
    would eliminate the errors and be more reliable
    when working on complicated calculations

          Other Early Attempts …                     (Babbage)

   His machine was called the ―Difference
       (because it was based on the
        mathematical concept of finite differences
        – an advanced math concept used to work
        thru complicated mathematical
   Babbage’s approach was to use the
    concept of repeated addition to
    replace the multiplication & division
    that had been done by hand.
       Using gearwheels to implement addition –
        much easier to implement than trying to
        also do multiplication & division…
     Other Early Attempts …               (Babbage)

   Babbage contacted members of the British
    Government to fund his project
   The British Government did fund Babbage’s work
    primarily for the overriding concern for the
    safety of sailors at sea (astronomy calculations
    were used for navigation)
   This is regarded as one of the world’s first
    government grants for research and
    technology development!
Other Early Attempts …                        (Babbage)

   Much time & effort was put into the design…

 As for the construction:

        Government changed
        Funding often ran out
        Limitations of Victorian age tools
        Babbage had ―personality differences‖ with many
         of those around him…
   After 10 years, all funding dried up, and it
    was never finished.
        Other Early Attempts…                (Babbage)

   The design called for:
       25,000 parts                      One HUGE
       An estimated weight of 15 tons    machine!
       A height of 8 ft

    (Note that even though it wasn’t implemented,)
    Charles Babbage is credited with inventing the first
    mechanical computer (in 1822)

Another note: His design also included a printer!
        Other Early Attempts …   (Babbage)

   Interesting sidenote:

    (Babbage later designed an
    ―improved‖ Difference
    Engine – which was never
    implemented as well.)

    In 1991, a perfectly
    functioning Difference
    Engine was constructed
    from Babbage’s original
          Babbage (con’t)
   The calculating engines of Charles Babbage
    are among the most celebrated icons in the
    prehistory of computing.
       Babbage’s Difference Engine (1st attempt) was the
        first successful automatic calculator and remains
        one of the finest examples of precision engineering
        of the time.
       Babbage’s Analytical Engine (yet another later
        effort) possesses all the essential logical features
        of the modern general purpose computer.
     Babbage (con’t)

   Babbage is known
    as the father of
    the computer

Interesting Babbage quote…

On two occasions I have been asked, –
 ―… Mr. Babbage, if you put into the
 machine wrong figures, will the right
        answers come out?"

         Other Early Attempts…              (Lovelace)

   Ada Lovelace, a mathematician who
    understood Babbage’s ideas, created a
    program for one of Babbage’s
    (for a machine that had not yet been
   She’s credited with being the first
    computer programmer
   The program she wrote is
    recognized as the world’s first
    computer program
   In 1979, the programming language
    Ada was named in her honor.
      The early attempts..

   How useful were these devices and
    Not very practical back then. Tools
    not available to fully develop them

So, fast-forward to the 1900’s…

      Inventions are typically the
      result of a need…

What was a significant event in the late 1930’s –
 early 1940’s that stimulated computer interest
 and development?????

         Needs of the army during

   Needed a more efficient way to calculate
    ballistic tables used for artillery and bombing

   Doing calculations by hand was too slow (took
    about 15 minutes each)

   (Ballistic table contained details on how various
    factors affect the flight of a projectile such as angle
    of fire, muzzle velocity, time of flight, etc)
          A new electronic computer..

   John Mauchly and J. Presper Eckert proposed
    an electronic (not mechanical) computer that:
       Could do ballistic calculations in 30 seconds
       Would require 18,000 vacuum tubes and require
        simultaneous function of almost all of them

        A new electronic computer
        (con’t) ..

   Reaction to Mauchly and Eckert’s proposal:
       OUTLANDISH!!!
       Mathematicians said: A vacuum tube typically
        fails every 15 minutes and on average, it took
        MORE than 15 minutes to find the bad tube.
        No useful work could EVER be done with this!!
       In spite of misgivings, army funded project in
       Machine called ENIAC (Electronic Numerical
        Integrator and Computer)
        And ENIAC was born…

   Time to complete:
       3 years
   Cost:
       $400,000
   Weight:
       30 tons (..and how many pounds are in a ton?)
   Size:
       30 by 50 ft

       Other uses for ENIAC:

   Weather prediction,
    atomic energy calculations,
    cosmic ray studies

   Replacing a bad tube meant checking around 18,000 tubes
To reprogram required rearranging patch cords (on the left)
and resetting some of the 3000 switches (on the right)
        Other computers of the time..

   1945 – Dr. John von Neumann developed EDVAC
    (Electronic Discrete Variable Automatic
   Introduction of: stored program concept
       Computer instructions are stored in main computer
        memory instead of requiring switches and wires to be
        changed whenever a new program was to be
   Main application of computers:
       Scientific or engineering applications

        Women were involved too..

   Rear Admiral Dr. Grace Hopper
    Was a visionary who realized that

    computers would reach a wider
    audience if they were more user
    friendly. She worked to develop
    an easier programming language
 Invented the compiler – an intermediate program that
translates English language instructions into the
language of the target computer
 Often cited as being the first recording of an actual computer
"bug" — a moth stuck in the computer (but term used previously)
        Then a shift in computer usage
        (toward business applic)
   1947: Mauchly and
    Eckert (from the ENIAC
    team) – designed and
    built computers for
    government and industry.
   UNIVAC 1:
       Used for 1950 govt census
       Also used by GE for payroll
                                      The first commercially available
                                      digital electronic computer

   What is a significant event that happens
    periodically in November that
    computers are used for today?

    1952 presidential election

   Who became president?
   Who was the opponent?

      UNIVAC 1 in the 1952 election

   UNIVAC 1 predicted the results (Dwight
    D. Eisenhower vs Adlai Stevenson after
    only analyzing 5% of the tallied vote.
   CBS (TV) didn’t believe the computer
    and withheld the info until it could be
    confirmed by actual votes

More details about UNIVAC 1

   Size:
       14 feet by 8 feet by 8.5 feet hig
   # of vaccuum tubes required:
       5200
   Weight
       29,000 lbs

           1stGeneration of Computers
           (1940’s –1950’s)
Primary Characterisic of 1G:
 Electronic circuitry consisted of vacuum tubes:

     Purpose:
          Act like an amplifier – could take very weak signals and make it
          Act like a switch – stop and start the flow of electricity instantly
     Disadvantages:
          Generated lots of heat
          Not very reliable
          Required lots of space
          Slow in processing data

 Vaccuum tubes (not yet extinct…)

   Until quite recently, what consumer
items used vaccuum tubes as their most
           common technology?

TVs and Computer Monitors…


What did 3 scientists (Bardeen, Brattain,
 and Shockley) invent in 1947 which led
 to 2nd generation of computers?

          2nd Generation of Computers
          (late 1950’s – mid 1960’s)
Primary Characteristic of 2G:
 Electronic circuitry consisted of
      More reliable and less costly than
       vacuum tubes
      1 transistor replaced the equivalent of 40
       vacuum tubes
      Part of it made from silicon – found in
       beach sand and glass – thus cheap to
      Transistors conducted electricity faster
       and better than vacuum tubes
                                                Vacuum tube vs transistor
      Purpose was the same: amplify
        or switch electronic signals
    The Transistor..
   Gave off virtually no heat compared to
    vacuum tubes

   Computers than become more reliable and

   But still had to be soldered into the circuits by
    hand, so size was still limited (resulted in mid-
    sized devices from radios to computers)

       The Transistor.. (con’t)
   The transistor is the key active component
    in practically all modern electronics.

   The transistor is often cited as being one of
    the greatest achievements in the 20th
    century and some consider it one of the
    most important technological breakthroughs
    in human history.

     Getting better.. But still falling short…
   At this point, computers contained circuits
    that contained hundreds or thousands of
    components such as transistors (amplifies or
    switches signals), diodes (allows current flow in one
    direction only), and capacitors (stores electrical charge)
   These components were hand-soldered
    together with wires.
   Time consuming, unreliable….

      More inventions..
   Jack Kilby & Robert Noyce independently
    invented the integrated circuit (IC) where
    components and connections were edged
    directly onto semi-conductor material

   Chips could then be printed as a unit by
    photolithography and not constructed one
    transistor at a time.

     The IC
   The first integrated circuits contained
    only a few transistors

   Known as ―Small Scale Integration‖

   HUGE impact in the development of

        3rdgeneration of computers
Primary Characteristic of 3G:
 Electronic circuitry consisted of integrated
  circuits (also known as semiconductor chip) --
     Characterized by the ability to pack a huge number
      of transistors on a single wafer of silicon.
     It allowed the entire circuit (transistors, capacitors,
      resistors, wires, etc) to be made out of silicon on a
      single board – taking up much less space
     Integrated circuitry was reliable, compact, and
      cheap to manufacture.
      3rd generation (con’t)
   The concept of integrated
    circuits was intricately tied
    to aerospace projects --
   Space missiles needed
    lightweight digital
   The use of ICs in the space
    program forced IC into
    mass-production (reducing
      Sidenote about transistors &
   Recall that circuits contain many many
   Note that electricity travels about a foot in a
    billionth of a second.
   Thus, the smaller the distance, the greater the
    speed of computers…
   Consequently – the more components that can
    be squeezed on a chip – the faster the computer
    can process…

     Some other computer-related
     events during 3rd generation ..

   1968: 8-inch floppy introduced
   1969: ARPANET network, predecessor
    to internet, is established
   Mainframes – primary computer type in
    existence although mini computers
    were starting to permeate..

        IC Development during that
   Medium Scale Integration (late 1960’s)
       Hundreds of transistors on a given chip

   Large Scale Integration
       Thousands of transistors on a given chip
       Early 1970’s: low 1000’s
       Mid-late 1970’s: 10,000+ transistors
   These improvements allowed more complex
    systems to be produced using smaller circuit
    boards, requiring less assembly work (because of
    fewer separate components)

     Integrated circuits..

    -- a picture of a
    microchip with a
    transparent window
    – showing the
    integrated circuit

       Getting closer, but still some

   Key weakness of the
    chips: they were
    hardwired for specific

   In other words, if you
    wanted a computer to
    do different tasks, it
    needed a chip per task

          Another invention…
   Ted Hoff designed the first microprocessor
       Consisting of a general-purpose logic device at its core
       Could be programmed by instructions stored on the
        semiconductor chip
       This was the first true ―CPU‖ -- which could handle many
   Hoff was an employee of Intel (name ring a bell???)
   This design led to the development of desktop
    computers (and the 4th generation!!)

          4thgeneration of computers
          (1971 – today)
   Characterized by two concepts:
       Invention of the microprocessor – a single chip
        that can do all the processing of a full-scale
       Monolithic integrated circuits (Very Large Scale
        Integration) – millions of transistors on one
        integrated circuit chip
        (Recall that the more components on a single
        chip – the faster the computer!!)


     The Digital Revolution..
   Computers, cell phones, and other
    electronic systems are now inextricable
    parts of the structure of modern
   It has been stated that the digital
    revolution – brought about by the
    microchip – was one of the most
    significant occurrences in the history of
      Some events during           4 th


   1976: Apple Computer Inc was formed
   1977: First popular home computers: Apple
    II, TRS-80, Commodore 64
   1981: IBM PC running MS-DOS is introduced
   1984: Apple introduces the Macintosh and the
    first graphical user interface (with a mouse..)

The original IBM Personal Computer   63
       Other 4th generation events..
   1987: 3.5‖ floppy disk introduced
   1989: WWW is created
   1992: Linux operating system introduced
   1993: Pentium processors introduced
   1994: Yahoo is founded; Bluetooth was invented
   1990’s-2000’s: Windows 95, 98, 2000, XP, etc
   1997: DVD technology introduced
   1998: Google is founded

      Other    4generation events

      (con’t) …
   1998: e-commerce (marketing goods and
    services) becomes popular
   2001: wireless technology becomes common
   2004: Blu-ray invented
   2007: iPhone invented

            ….. and on and on….

Just for fun – Twenty Key Inventions of the last
  25 years… Do you agree? Do you have others?
 Cellphones                       Digital cameras
 Laptop computers                 Doppler radar
 BlackBerries                     Flat-panel TVs
 Debit Cards                      Electronic tools
 Caller ID                        PowerPoint
 DVDs                             Microwavable popcorn
 Lithium rechargeable batteries   High-tech footwear (e.g., Air
 iPods                            Online stock trading
 Pay at the pump                  Big Bertha golf clubs
 Lettuce in a bag                 Disposable contacts