Transcript The 1600`s - BigBozoid

Mathematical Tables
 Scientists
 Navigators
 Engineers
 Surveyors
 Actuaries
A random selection of 40 volumes of numerical tables contained
3,700 acknowledged errata and ?!?!?!? unacknowledged ones
Dionysius Lardner (1834)
1800’s
Further development of
mechanical calculating
machines
Thomas de Colmar
 stepped drum gears
 reverse the operating function
in the result registers (up to 16
digits), allowing reliable, stable
calculation over extended
periods of time without gear realignment
1785-1870
arithmometer
1820 -1830
1500 models sold
 banks
 insurance companies
 similar businesses
Thomas promotes arithmometer
Piano Arithmometer
Gift for Tsar Nicolas I
Maurel & Jayet
1840’s
 Took basic design of Thomas and greatly
improved it
 Results as high as 8 digits
 Transmission too
delicate
The Arithmaurel
Odhmer
1845-1903
Swedish engineer
Baldwin
1838 to 1925
American engineer
fluted drums replaced by a "variable-toothed
gear" design: a disk with radial pegs that can be
made to protrude or retract from it.
Pin-wheel mechanical calculators
The typewriter
Introduction of the keyboard
The first adding machine
with keyboard
It was feasible because of
a carry mechanism fast
enough to act while the
keys return from being
pressed
Worldwide success
Dorr E. Felt (1862-1930)
Comptometer
Chicago 1884
The disadvantages of
these machines
 Operation required direct manipulation by
the operator
 Multiplication performed as successive
additions
 Keyboard improved speed but…
 Well trained operator still necessary
Charles Babbage
1791 - 1871
 English mathematician
Born in Teignmoth, Devonshire, UK
 analytical philosopher
 proto-computer scientist
The Difference Engine
o
N
1
Designed to produce mathematical tables
Construction funded by British government
and Babbage himself
Never completed
Babbage lost interest in this device
when he realized that its design was
flawed
He started working on
Difference Engine No 2
The Difference Engine No 2
design completed 1830
built 1991
The Analytical
Engine
Babbage formulated ideas for it between 1834-1837
The Analytical Engine
Store - 1000 50-digits numbers
Mill – (CPU) added, subtracted,
multiplied or divided, and
returned a result to the store
Punched cards – several
readers for programs and data

Printer for output making
hardcopy data available to the
user
Why did Babbage not invent
the computer?
 Machine tools not adequate in his day
 Mathematics and logic not sufficiently
developed
 Mechanical memory store just too
slow and too limited to hold a useful
program
Augusta Ada Byron
Countess of Lovelace
 Daughter of Lord Byron
famous romantic poet
 Her mother did not want
her to grow up to be a
poet….
 Competent mathematician
 Member of London’s high
society
Ada 1815 - 1852
 Met Babbage when she was 17
 Public relations for Babbage
 Translated an article by Luigi
Menebrea on the A.E. and added
extensive notes
 Some give her credit for writing
the first computer program
Herman Hollerith
Electronic tabulation of statistical data
 New Yorker of German origin
 Trained as a mining engineer
 Ph.D at MIT
1860-1929
 Developed a mechanism for reading holes in the
cards using spring-mounted needles
Needles passed through the holes to make
electrical connections to trigger a counter to record
one more of each value
1890 census completed in
record time
• Built tabulators on a contract for the US government
• Many other governments wanted tabulators too
• Started Tabulating Machine Company in 1986
• Merged with 2 others in 1911
• Changed name to IBM in 1924