John Vincent Atanasoff, a professor of Physics
at Iowa State University conceived the first digital all-electronic
computing device during his researches to solve linear equations,
which comprises simultaneously an electronic circuit including a
scanning mechanical memory using capacitors. Originally the memory
of the computing device consists of a set of drums provided with
electrical contacts displayed as
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Fig 355 - The ABC computer. Replica of the
first computing device invented by Dr. Astanasoff, displayin
the rack provided with valves responsible by the machine operation.
Courtesy: Iowa State University - USA |
Fig. 355A - The computing device side view.
Courtesy: Iowa State University - USA |
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Fig. 355B - Dr. Astnasoff’s associate,
Cliff Berry operating the first all-electronic computing
device.
Courtesy: Iowa State University - USA
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Fig. 355C - Exploit view of the first
all-electronic device developed by the physicist John
Vincent Atanasoff working at Iowa State University –
USA.
Courtesy: Iowa State University - USA |
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small brass pins, which were connected with paper capacitors whose
loading operation was monitored and adjusted by an electrical circuit.
The arithmetic and logic functions were fully electronic operated
by using 255 double triode valves. Fig 355
In the beginning of WWII the electromechanical computers availables
were the ones such as the ASCC – Automatic Sequence Controlled
Calculator – developed by IBM in the USA. They were not so
fast to solve the complex ballistic calculus required by the new
weapons used in the air warefare.
In this way considering the computing device developed by Atanasoff
was an all-electronic concept, no longer depending of the former
flip flop circuit it can be considered as the forerunner machine
to use the thermionic valve in the inceptive computing science.
Thus in June 5, 1943, the American government signed a contract
with the University of Pennsylvania to develop the ENIAC project,
or Electronic Numerical Integrator and Computer. Three years later,
the era of digital computer was ushered in with the dedication of
ENIAC. Accounts of the day are reminders of how awesome the new
computer was. It uses circa 18.000 thermionics valves and its U-shaped
framework weighted 30 tons, occupying a 250-m2 room, and consumes
around 150 kW of power.
Operating with a basic clocl rate of 100 kHz, it oculd perform additons
in 0,2 us, while multiplication took
about 2.8 us respectively.
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Fig. 355.d – Dr. John Vincent Atanasoff
inventor of the first all-electronic computing device originally
developed for processing complex linear equations.
Courtesy: Iowa State University - USA
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Instead of binary notation, ENIAC used decimal notation and could
handle up to 10 decimal digits with decade counters functioning as
accumulators, which stored the numbers in the machine.
ENIAC’s first practical chore was to perform calculation problems
for the famous and top-secret Manhatan project, responsible to develop
the first atomic bomb in 1945.
But in spite of its advanced technology, the ENIAC had drawbacks.
Since a patch board of wiring controlled it, the changing of a program
was a cumbersome too slow operation.
In this way in order to improve the processing speed it would be
mandatory it could store the program electronically in the same
way the machine stored the data. Fig. 356
In the early days of the computer engineering,
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Fig 357 – Close up of the valve 7AK7.
This medial transconductance sharp-cutoff pentode provided with
two control grids to be used with locktal socket was the first
valve developed for digital application. It was designed in
the research laboratories of Sylvania Company in the USA, circa
1948, to meet the requirements of the computing system as know
as “Whirlwind Project”.
Ludwell Sibley collection, KB2EVN, USA. |
memory controlled the architecture design in such way the only electronic
memory element available for data being processed was the expensive
technique known as the flip-flop valve circuit.
By a continously improvement in the computing sciences, in 1946,
the University of Pennsilvania”Moore School of Electrical
Engineering, started the development for a new type of computer
as known as “EDVAC” – Electronic Discrete Variable
Computer -. It used a new data storage system technology now available
as the mercury delay line, as a result of radar research associated
with the war.
In the reality de designer noted that if the signals propagated or
delayed, through the mercury were amplified and recirculated, the
information could be held in the line indefinitely and could be accessed
each time it came around.
Furthermore Europe was already involved in electronic digital calculator.
In 1943, pressed by the war effort the Bristish developed the “Colossus”,
a 1.500-valve cryptanalysis machine. The specialized “Colossus”
was the British beachhead moving to coordinating its developments
by establishing the National Mathematical Laboratory in 1945 where
it were developed The “Williams Tube” considered as the
first all-electronic memory as well as the new computing sytem –
EDSAC – Electronic Delay Storage Automatic Computer –
In the later forties it was launched in the market the first valve
operational DC amplifier. This high-gain, low drift circuit ushered
in the era of the fully electronic analog computer.
Therefore in spite of the great innovation in the thermionic science
as the time being the available valves were originally devoted for
radio receivers manufacturing only, and in this way they did not
match the performance required to operate in the logical circuit
of the first computers.
New researches led companies like Sylvania in the USA to develop
the first family of pentode valves specifically to behave as an
element of digital logic, as for instance the type 7AK7. Fig 357
As aforementioned from 1940 to 1950 it was a period of feverish activity
in computer research and development, which certainly contributed
so much to the improvements in the new generation of computers. Fig.
358
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Fig. 356 – The computing device as known
as ENIAC. |
Fig 358 – The computing system developed
by General Electric Company circa 1950. Unlike some other types
of computers, the OMIBAC –Ordinal Memory Inspecting Binary
Automatic Calculator – uses the binary system of counting.
It is a simplified system, which employs two digits only, 1
and 0, rather than the more familiar 10- characters of the decimal
one.
Radio Electronics. |
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