Transcript A brief history of computers and computing: Part II

The history of computers and
computing: Part II
The computers of the 20th century and the
people behind those machines.
James Tam
Konrad Zuse
Developed a series of mechanical calculating machines (Z1,
Z2, Z3, Z4).
He was the first person to construct a calculator that could
run automatically
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The Bell Complex Number Calculator
The Bell Computer could add, subtract, multiply and divide
complex numbers
Employed simple switches and flash bulbs
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The Bell Complex Number Calculator (continued)
It was the first machine to:
•handle multiple terminals
•be operated remotely
Photos courtesy of Bell Technologies Inc.
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The Bell Complex Number Calculator (continued)
The computer used it’s own form of binary, Binary Coded
Decimal (BCD).
Decimal value
BCD value
0
0011
1
0100
2
0101
3
0110
4
0111
5
1000
6
1001
7
1010
8
1011
9
1100
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The Harvard Mark I
Manufactured by IBM and was donated to Harvard
University.
Extremely accurate
Used by the U.S. navy (bureau of ordinance)
Frequently used as a design model in subsequent machines.
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John Atanasoff, Clifford Berry, and the ABC
(Atanasoff-Berry Computer)
Atanasoff needed a computer to perform specialized
calculations
He got his inspiration for the ABC in a bar.
A photo of Clifford Berry and the ABC, courtesy of Dr. Atanasoff
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The ENIAC
Developed for the U.S. army at the Moore School of
Electrical Engineering (University of Pennsylvania)
Picture from the History of Computing Technology by Michael R. Williams
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The ENIAC (continued)
Used vacuum tubes to store information
All this could store one digit!
It was huge, complex and extremely expensive
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Alan Turing
A British Mathematician
He worked at Bletchley Park as a code-breaker (contributed to the design
of the machinery as well as applying his Mathematical knowledge)
An Enigma encoding machine
Pictures from the History of Computing Technology by Michael R. Williams
James Tam
The EDSAC (Electronic Delay Storage Automatic
Calculator)
The first reliable computer to actually incorporate memory
(The first computer design conceived that incorporated
memory was the EDVAC/Electronic Discrete Variable
Arithmetic Computer but it was completed after the
EDSAC).
Picture from the History of Computing Technology by Michael R. Williams
James Tam
EDSAC (continued)
First demonstrated in 1949 (ran at 500,000 Hz / 0.5 MHz)!
A spin-off of the EDSAC (called LEO / Lyons Electric Office)
was the first computer to be used for commercial data
processing.
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The Stretch
One of the first super computers
The whole “Stretch”
Control panel for the Stretch
Pictures from the History of Computing Technology by Michael R. Williams
James Tam
Summary
Some of the more ground breaking computer systems and personalities of
the 20th century.
•Konrad Zuse and the “Z” series of computers.
•The Bell Complex Number Calculator
•The Harvard Mark I
•Atanasoff, Berry and the ABC
•The ENIAC
•Alan Turing
•The EDSAC
•The Stretch
James Tam