Title: J. Lyons accounting office 1900
1J. Lyons accounting office1900
2Analytical Calculation
- Reduce a problem to a 2nd and then a 3rd
- Application of rules and procedures
- Problem is solved by the machine itself
3Analytical Calculator
- Governed by a flexible programming system
- Equipped with a modifiable control unit
- no human intervention
4Electromagnetic relay
Joseph Henry1797 - 1878
5The electronic revolution
- Edison effect (1883) electric current passes
from hot to cold electrode in a vacuumelectrons
are expelled from the hot wire
Thomas A. Edison1847 - 1931
6Flemings valve
- Positively charged metal plate in the tube.
- Free electrons expelled by the heated filament
all precipitate onto the plate generating
electric current
diode 1904
7Triode
- inserted a third electrode into the tube, between
the plate and the filament - Amplified the incoming current
1907
8Flip-flop device dual triode
- Bistable electronic device
- Incoming current flips both triodes into an
opposite state
9Electro-mechanical calculation
- Based on electro-magnetic relays
10George StibitzBell Laboratories
- Model K literally built in his kitchen 1937
- a binary half-adder from phone relays, possibly
the first binary calculator - Remote job entry
- Floating point arithmetic
11Zuse German Pioneer
Patent applied for 1936
12Claude Shannon
- described the similarity between symbolic logic
and switching circuits - In 1936, he coined theterm bit from binary
digit, the smallest particle of computer
information
13Harvard - IBM Mark 1 US navy ballistics
- Completed in 1941
- 16 m long, 2.6 m high, 0.6 m deep
- 5 tons
- 850 km of wire
- 1.75 x 105 connections
Howard Aiken
1900 -1973
- Although inspired by Babbage, it had no
conditional branching
14Automatic Sequence Controlled Calculator
Harvard Mark I
15John Vincent Atanasoff1903-1995first
general-purpose electronic digital computer
J. Atanasoff and C. Berry
16The ABC Machineproblems involving systems of
simultaneous linear equationsnever finished !
- Binary digits to represent all numbers and data
- Performed all calculations using electronics
rather than wheels, ratchets, or mechanical
switches - computation and memory separated
17The ABC Machine
- 320 kg
- 1.6 km of wire
- 280 dual-triode vacuum tubes
- 31 thyratrons
- about the size of a desk.
18Colossus designed byThomas Harold FlowersAlan
TuringM.H.A. Newman
1905-1998
- assisted the code-breaking efforts at Bletchley
Park - first digital (partially) programmable,
electronic computer - Completed in 1943
19Bletchley Park
- British decoded 75,000 of the 80,000messages
they intercepted
World War II
20Colossus
- Capable of performing binary logic calculation
- Capable of conditional branching
- Capable of automatically printing
- Capable of storing programalready written for
the purpose of executing pre-selected functions
21Electrical Numerical Integrator and Calculator
- ballistic tables
- weather prediction
- atomic-energy calculations
- cosmic-ray studies
- thermal ignition
- random-number studies
- wind-tunnel design
Eniac
22ENIAC another monster machine
- 72 m2
- U-shape 6 m wide by 12 m long
- 18,000 vacuum tubes
- 200 kilowatts of power in operation
- 10,000 condensers
- 6,000 switches
- 1,500 relays
23None of these machines was a true computer
- All closely resembled Babbages Analytical engine
- Program executed independently of results
- Process could not change in function of the
results
24Alan Mathison Turing1912-1954
a machine which can be made to do the work of
any special-purpose machine, to carry out any
piece of computing, if a tape bearing suitable
"instructions" is inserted into it
25War hero, athlete, mathematician, computer
scientist
- I believe that, at the end of the century,
the use of words and general educated opinion
will have altered so much that one will be able
to speak of machines thinking without expecting
to be contradicted. A. Turing
26The Turning Test