The Life and Contributions of Konrad Zuse
Konrad Zuse was
a German engineer and A pioneer of modern Computing.
His work on the Z3 (1944), the first tape stored program controlled computer,
is considered to be the first automatic digital computer as later it was found
that it predated the Harvard Mark I
(1944) by 3 years.Although Zuse
has a degree in civil engineering, he was years ahead of his time. He developed
the Z1 in his parents living room without outside
knowledge of the developments in computer technology. Konrad Zuse
first started to consider the logical and technical principles of computers as
far back as 1934 when he still was a student. He also created the world's first
programming language, which he called the Plankalkul.
This site is designed to enlighten people on Konrad Zuses contributions to the
field of computing and on on Konrad
Zuse the Man
I. Early Life
One of the paintings that Zuse Sold to fund his studies (1926) © Horst Zuse
II. Concepts of Computing and the Z1
|
In 1934, Zuse had an idea for a machine to
eliminate the need for tedious calculations by hand which were in abundance for
his profession as a civil engineer. He posed a question of what such a
machine would do: What mathematical problems should a computing machine solve? His answer was the following definition of computing: To build new specifications from given specifications by a
prescription. In the year 1943 he extended the definition to: Computing is the deviation of result specifications to any
specifications by a prescription. From these definitions, Konrad
Zuse defined the logical architecture of his Z1,
Z2, Z3, and Z4 computers. He wanted his computer to be fully programmable.
Also he wanted to utilize the binary number system which was not truly
implemented on computers world wide until years later. Not only should the
numbers be represented in a binary form, but the whole logic of the machine
should work using a binary switching mechanism. He planned a high performance
binary floating point unit in the semi-logarithmic representation, which
would allow him to calculate very small and very big numbers with sufficient
precision. He implemented a high performance adder with a one-step
carry-ahead and precise arithmetic exceptions handling. He developed a memory
in which each cell could be addressed by the punch tape and could store
arbitrary data. Finally, he constructed a control unit that controlled the
whole machine, and implemented input and output devices from the binary to
the decimal number system and vice versa. |
From 1936 to 1938, Zuse
constructed the Z1. The Z1 was a remarkable machine. The Z1 did not use relays,
but instead consisted completely of thin metal sheets, which he and his friends
produced using a jigsaw. The only one electrical unit was an electrical engine,
which was used to provide a clock frequency of one Hertz. The Z1 was programmed
via a punch tape and a punch tape reader. There was a clear separation between
the punch tape reader, the control unit (which supervised the whole machine and
the execution of the instructions), the arithmetic unit (with registers R1 and
R2), the memory, and the input/output devices. In 1986, Konrad
Zuse decided to rebuild the Z1 ,
because the architecture of the Z1 was almost identical to that of his Z3
computer (discussed below), which was unfortunately destroyed in the Second
World War. Most of the components are self-explanatory. The memory, which
consisted of 64 words, each containing 22 bits, was formed from three blocks.
The first block contained 64 words for the exponents and signs (8 bits for each
word). The other two blocks each contained 32 words for the mantissa (14 bits
for each word). The selection unit interpreted the address for the memory by
the control unit. The arithmetic unit was an adder, and all of the operations
were reduced to additions or subtractions (adding and subtracting are very
similar operations). The registers R1 and R2 Registers were two words, each
containing 22 bits. The two circles on the left-hand side (on the clock
generator block) are cranks for executing
A high level block diagram of the Z1
The rebuilt Z1 seen from a
"birds-eye" view.
© Horst Zuse
(Source:
III. Z2 and
Z3 Computers
World War II
made it impossible and undesirable for Zuse and
contemporary German computer scientists to work with similar scientists in the
Unsatisfied with the reliability of the
binary switching metal sheets used in the Z1, Konrad Zuse next constructed the Z2 computer. The Z2 used the same
type of mechanical memory as the Z1, but he used 800 old relays from phone
companies to construct the arithmetic and control units. The Z2’s arithmetic
unit consisted of a 16-bit fixed-point engine, because he wanted to test the
reliability of relays for arithmetic calculations. Unfortunately, photos and
plans of the Z2 were destroyed by allied air raids during the war. However, the
Z2 served its purpose, because it convinced my father that relays were indeed
reliable, and he subsequently built his Z3 computer completely out of relays
(600 for the arithmetic unit and 1,800 for the memory and control units).
Konrad Zuse
with the rebuilt Z3 in 1961. The memory is on the left. The arithmetic
unit with the stepwise relays are on the right, and the console with
punch tape
reader is on the front left.
©Horst Zuse
Helped
by friends and with some small support from the government, Konrad
Zuse constructed his Z3 machine from 1939 to 1941 in
the Methfesselstrabe 7 in Berlin-Kreuzberg.
He wanted to use the Z3 to demonstrate that it was possible to build a
reliable, freely programmable computer based on a binary floating point number
and switching system, which could be used for very complicated arithmetic
calculations. For reliability reasons he used relays for the entire machine.
During
his life, Konrad Zuse
painted some hundred oil paintings. He held about three dozen exhibitions, and
he also sold the paintings. After 1964 one of Zuse’s
passions was painting. Zuse mostly painted in oil, but
sometimes he painted with chalks. Very often he painted skyscrapers, cities,
and bridges, visions of cities and abstract structures.
V. Awards and Accomplishments
In
1956, Konrad Zuse received
the Dr.-Ing. e.h.
for his achievements in the area of computing from the Technical University of
Berlin. In 1965, he was given the Werner von Siemens Award in
Konrad Zuse is responsible for many of
the fundamentals used today in computer science. Some of those contributions include :
·
The
use of the binary number system for numbers and the circuits.
·
The
use of floating point numbers, along with the algorithms for the translation
between binary and decimal and vice versa.
·
An
algorithm for the non-restoring calculation of the square-root. With this
algorithm, the square-root can be calculated with n steps, if n is the number
of digits. This technique was not known in the
·
The
carry-look ahead circuit for the addition operation
·
Look-Ahead:
The program is read two instructions in advance, and it is tested to see
whether memory instructions can be performed ahead of time.
·
Pseudo-memory:
In case the look-ahead mechanism finds that a number that is to be restored is
needed again within the next two instructions, the number is placed in a
register of mechanical contacts where it is available with no access time. For
this purpose, the memory has two registers of reading contacts
·
Special
values (Sonderwerte): If a result exceeds the
capacity of the arithmetic unit, it is designed as Sonderwert.
This principle guarantees that the machine always calculates correctly.
·
The
most unusual feature was undoubtedly the mechanical binary cells that made up
the memory. The memory has 64 words with 32 bits (Z1 and Z4). These devices
were completely different from mechanisms in contemporary cash registers or
desk-top calculators. The elements could be used not only for storage, but also
for calculation, for example for address coding. A relay memory would have
required about 2500 relays, which would have more than doubled the size and the
weight of the Z4 computer.
·
The
Plankalkül as the world's first complete high-level
language in 1945/46 (final edition).
VI. References
The Life
and Work of Konrad Zuse
– By Prof. Horst Zuse (K. Zuse's
son); an extensive and well written historical account
Konrad Zuse – Wikipedia, the Free Encylcopedia
Evan Seaman
Dec 20, 2005
Stony Brook University
CSE 301 – History of Computing
Fall Semester