1. Who Invented the Computer
Who Invented the Computer? Babbage, Atanasoff, Zuse, Turing or von Neumann?
Raj Reddy
Carnegie Mellon University
Sep 23, 2013
Talk given at Heidelberg Laureates Forum on
Origins of Computing
Good Morning.
In this talk, we will provide a summary of two aspects of the evolution of Computers:
The concepts and technologies that were seminal in automation of computation, and
the people that were principal players in the invention of the modern computer.
Following that, we will address the topic of this talk, “Who invented the computer”?

2. 3 Stages of Information Revolution
Invention of Writing 3000BCE
Hieroglyphs, Kanji Characters
Mesopotamia: Sumerian cuneiform writing on clay tablets
Egypt: writing in hieroglyphic script
Invention of Alphabet for simplified writing and learning, and communication with slaves
Invention of Printing 1450CE
Guttenberg Press
Democratization of knowledge
Invention of Computer 1950CE
Passive knowledge to active knowledge
Invention of writing has been central to the rapid progress of the human race during the past 5000 years. Writing enabled the creation and communication of knowledge from generation to generation. The invention of printing, in the 15th century, led to the widespread access to that knowledge. And the invention of the computer made it possible to transform passive knowledge into active knowledge.

3. Representing Numbers Roman Indo-Arabic Binary I 1 1 V 5 101 X 10 1010L C D M
CXXVIII = =
It took almost 2000 years to go from complex hieroglyphics to a simpler alphabet for writing and it took another 1000 years to invent the positional number system, the concept of ‘zero’ and to formalize the algorithms for arithmetic.

4. Tools for Calculation: Abacus
Representing Numbers in Abacus
Bi-Quinary Representation
(also used in early computers Colossus, IBM650 and Univac)
Abacus was the first attempt to create a tool for calculation. A traditional abacus uses bi-quinary representation of digits. Interestingly, this notation was also used in some of the early electronic computers such as IBM 650 to improve reliability of systems built using unreliable components.

5. Tools for Calculation : Slide Rule
John Napier ( )
Discovered
Logarithms
Simplifying arithmetic computations
Popularized the use of Decimal Point
Slide Rule: Represents Numbers
on a Logarithmic Scale
On a logarithmic scale an equal difference in order of magnitude is represented by
an equal distance
John Napier’s discovery of logarithms in the 16th century led to the invention of analog computation and the creation of a slide rule. It was in use for nearly 400 years until the invention of the electronic calculator.

6. Blaise Pascal (1623-1662) Known for Co-Founder of Probability Theory
Pascal’s Triangle for Binomial Coefficients
Pascaline Mechanical Calculator
Only addition and subtraction
Pascal Programming Language named after him
Now we will look at several attempts leading up to the creation of the digital computer. French Mathematician Blaise Pascal was the first to invent the earliest known digital mechanical calculator. This device called Pascaline could only do addition and subtraction. It was not a commercial success because of cost and reliability issues.

7. Gottfried Wilhelm Leibniz (1646-1714)
Known for
Co-Inventor of Calculus with Newton
Binary Number Systems (Explication de l'Arithmétique Binaire -1703)
Calculus Ratiocinator: Algebra of Logic as a Calculus of Human Reasoning
Formal Logic: Forerunner of Symbolic Logic
Leibniz Pinwheel Calculator
Capable of multiplication and division
Legendary Polymath Gottfried Leibniz contributed many concepts relevant to modern computation including binary arithmetic, algebra of logic, and the design for the pinwheel calculator. The pinwheel design was the primary mechanism used in most mechanical calculators until the last century.

8. George Boole (1815-64) Algebra of Numbers
Semantics of Addition, Subtraction, and Multiplication of Numbers are well understood
Algebra of Sets and Propositions (Boolean Algebra)
Semantics of Addition, Subtraction, and Multiplication in Boolean Algebra are sometimes different
If X=all men and Y=all women
X+Y is all men and women
If X = all people and Y = all children
then X-Y is all Adults
But
X+X=X not 2X
X.X = X not X2
Both Algebras Agree if X=0 or 1
0.X = 0 and 1.X = X
Claude Shannon Demonstrated in 1938
that Algebra of Switching Circuits is
equivalent to Algebra of Propositions
George Boole was the first to realize the need for Algebra of Sets and Propositions much as we have an Algebra for Numbers. In spite of his work and of Leibniz before him and Frege after him, the relevance and importance of symbolic logic was not well understood or appreciated by the designers of early computers. Maurice Wilkes, one of the Turing Award winners in the l960s and a pioneering computer architect in the United Kingdom during the 40s and 50s said, in the 2009 ACM interview, that the work of Turing and the mathematicians before him had little impact on the evolution of computers. Never the less, after Claude Shannon demonstrated the equivalence of the algebra of switching circuits to the algebra of propositions in 1938, mathematical logic provided the theoretical underpinnings for the subsequent evolution of computers.

9. Babbage and Lovelace Inventors of the First Computer and Software
Designer of the Analytic Engine
First Programmable General Purpose Computer
First Use of Punch Cards and Storage Registers
First software program developed by Lady Lovelace
Analytical Engine proposed to use a
A Store (Memory) with digit words
Arithmetic Unit (ALU)
Sequential Control of Instructions (CPU) with Conditional Branching
Punch Card I/O
Software on Punch Cards Replacing Fixed Automation by Programmable Automation
Stored Program Computer? Represents Programs as
Data, but on Punch Cards
Missing Elements of Babbage’s Design
No Binary Arithmetic or Floating Point
No Working Prototype
Babbage’s Analytical Engine was the first programmable general purpose computer, the first to use punch cards in computation, first to use storage registers. This architecture led to the first software program developed by Lady Lovelace. Babbage was the first to realize the need for a general purpose, programmable mechanism. After having built the fixed function Difference Engine earlier, he designed the Analytical Engine, a programmable universal computer including the ability to specify conditional and iterative computations, but did not use binary arithmetic or floating point. Babbage stored programs and data on punch cards which anticipated the concept of the stored program computer.
The following video illustrates the features of the Analytical Engine.
Babbage’s design was never built into a working prototype.

10. Click here to see Babbage and Lovelace video
Babbage and Lovelace First to Design a Programmable General Purpose Computer
Click here to see Babbage and Lovelace video

11. Alan M. Turing (1912-54) Turing I: Universal Turing Machine (1936)
Proposed an Abstract Digital Computing Machine, now called a Universal Turing Machine (1936), formalizing the
Concepts of Algorithm and Computation
Concept of a Programmable Computer
Concept of a Program
and Programming
Concept of a Stored Program Computer
Concept of a Subroutine
Read, Write and Erase on an Infinite Paper Tape
Modern Computers also Read, Write and Erase
albeit with finite memory
Turing made three distinct contributions to the evolution of digital computers, one in 1936, second in 1940 and third in In 1936, Turing proposed the concept of an abstract digital computing machine now called the Universal Turing Machine. It formalized the concepts of algorithm and computation. It introduced the concept of a program and programming, the concept of a programmable general purpose computer, the concept of a subroutine and the concept of a memory with read, write and erase functions. His design anticipated the concept of treating programs as data, which was later called a stored program computer. He assumed that he would have infinite memory. Most modern computers only have finite memory capacity, although a petabyte is almost infinite for most of us.

12. George Stibitz ( ) BTL1 1936
Stibitz is acknowledged as an early pioneer in the digital computer revolution
BTL1 is known for
Complex Multiplication and Division
(x + yi)(u + vi) = (xu – yv) + (xv + yu)i
3 multiplications and 3 additions
Needs a sequence of calculations and
storing intermediate results
Fixed Function – Not programmable
First Computing Device ever used
Remotely over Phone Lines
Boolean Logic for Circuit Design
George Stibitz built one of the early sequence controlled devices capable of complex multiplication and division using electro mechanical relays.

13. Howard Aiken ASCC: Automatic Sequence Controlled Calculator (Harvard Mark I) 1936
Howard Aiken is acknowledged as an early pioneer in the digital computer revolution
Harvard Mark I is known for
One of the Largest Computers 51’x8’x2’
Weighing 10,000 pounds
Electro-Mechanical
Programmable
Sequence of instructions from
24 channel paper tape
No conditional branching
Decimal Arithmetic
72 Storage Counters with 23 digit
signed decimal numbers
Howard Aiken, with the help of IBM, built one of the largest computing devices called the automatic sequence controlled calculator, ASCC. It was programmable and used a 24 channel paper tape and used decimal arithmetic. It weighed 10 tons!

14. John Atanasoff ( ) ABC 1936
John Atanasoff is acknowledged as an early pioneer in the digital computer revolution
Atanasoff-Berry Computer (ABC)
ABC is known for
First Electronic Digital Computer
arithmetic logic functions were fully electronic
logic gates ranged from inverters to two
and three input gates
Binary digits represent all numbers
and data
Fixed Function – Not Programmable
No Stored Program
Regenerative capacitor memory
John Atanasoff is acknowledged as the early pioneer who developed the first electronic digital computer and used binary arithmetic. However the Atanasoff-Berry Computer, the ABC, was not programmable and as a result, was not capable of doing different diverse computational tasks. It was a fixed function, special purpose computer for solving linear equations.
The following video highlights Atanasoff’s contributions.

15. Click here to see Atanasoff’s video
John Atanasoff ( ) First to Develop a Working Electronic Digital Computer with Binary Arithmetic
Click here to see Atanasoff’s video

16. Konrad Zuse ( ) Z3 1936
Konrad Zuse is acknowledged as an early pioneer in the digital computer revolution
Z3 is known for
First working, program-controlled, general-purpose, electro-mechanical relay computer
Sequence of Instructions on Tape
Conditional Branching missing
First to use Binary Representation
First use of Floating Point
Single Address Instructions
Operation, Operand
First Programmable Computer
Konrad Zuse was the first to develop a working, programmable, general purpose computer and used binary floating point arithmetic. The program instructions were stored on a 35mm film tape. The programming structure and the architecture was not fully general purpose in that it did not have conditional branching and iteration functions.
The following video highlights Zuse’s contributions.

17. Click here to see Zuse’s video
Konrad Zuse ( ) First to Develop a Working Programmable General Computer with Binary and Floating-point Arithmetic
Click here to see Zuse’s video

18. Turing II Bombe (1940)
Bombe was an electromechanical device used to decipher German Enigma-machine-encrypted secret messages
Developed by Alan Turing and Gordon Welchman
Produced in 1940 at the UK Government Code and Cypher School
Bombe was
An Electro-mechanical Special Purpose Computer
The First to be used in Symbolic Computation
The First to be used as a Parallel Computer
The bombe was an electromechanical device used by British cryptologists to help decipher German Enigma-machine-encrypted secret messages during World War II. The initial design of the bombe was produced in 1940 at the UK Government Code and Cypher School (GC&CS) at Bletchley Park by Alan Turing and Gordon Welchman.
Bombe was the first system to be used for symbolic computation and first to use multiple machines for parallel computation

19. Tommy Flowers Colossus (1943)
Colossus was the world's first electronic digital computer that was at all programmable
Used for Code Breaking during WWII
Colossus
Used state-of-the-art vacuum tubes
First working implementation of a programmable electronic computer
Atanasoff’s was not programmable
Colossus was the world's first electronic digital computer that was at all programmable. The Colossus computers were used by British codebreakers during World War II to help in the cryptanalysis of the Lorenz cipher. Colossus was designed by engineer Tommy Flowers to solve a problem posed by mathematician Max Newman at the Government Code and Cypher School at Bletchley Park. The prototype, Colossus Mark 1, was shown to be working in December 1943 and was operational at Bletchley Park by 5 February An improved Colossus Mark 2 first worked on 1 June 1944, just in time for the Normandy Landings. Ten Colossus computers were in use by the end of the war.
Being not widely known, it therefore had little direct influence on the development of later computers; EDVAC was the early design which had the most influence on subsequent computer architecture. However, the technology of Colossus, and the knowledge that reliable high-speed electronic digital computing devices were feasible, had a significant influence on the development of early computers in the United Kingdom and probably in the US. A number of people who were associated with the project and knew all about Colossus played significant roles in early computer work in the UK.

20. Eckert and Mauchly ENIAC: Electrical Numerical Integrator and Computer 1945
Eckert and Mauchly provided key leadership in the emergence of Electronic Digital Computer
Responsible for emergence of global digital computer industry along with IBM
Eckert Mauchly Computer Corporation 1948
ENIAC Known for
First Large Scale Electronic Computer
First to become operational
Far Faster than any another existing computer
Programming by Plugboard
Too slow
Full Conditional Branching
Decimal Arithmetic
20 10-digit accumulators
Punch Card I/O
Led to EDVAC Report
Training Ground for Many Successors
Eckert and Mauchly built ENIAC, the first large scale electronic computer. It was programmable by wiring a plug board and used decimal arithmetic and punch card input and output. They were responsible for the emergence of the global digital computer industry and started the Eckert and Mauchly Corporation in 1948 and competed with IBM from the beginning.

21. John von Neumann with Goldstine, Eckert and Mauchly
EDVAC Report (1945): Electronic Discrete Variable Automatic Computer
Based on discussions with Goldstine, Eckert and Mauchly
A Design for a Programmable Electronic Digital Computer
a processing unit: an arithmetic logic unit and processor registers
a control unit: an instruction register and program counter
a memory to store both data and instructions
external mass storage, and
input and output mechanisms
Concept of a Stored Program
Concept of Instructions as Data
Instructions and Data in same Memory
Concept of sequential flow of control
A “program counter” that indicates the current
point that has been reached in execution
of a program
Concept of a variable
“named” storage locations in which a value
may be stored and subsequently referenced
John von Neumann, one of the foremost mathematicians of the 20th century, with contributions to many fields such as self-replicating machines and stochastic computing, set theory and game theory, and quantum mechanics and fluid dynamics. Von Neuman synthesized and formalized earlier ideas into a coherent EDVAC report, based on discussions with Goldstine, Eckert and Mauchly. It proposed a design architecture for a programmable electronic digital computer, the concept of a stored program, the concept of sequential flow control and the use of a program counter to specify the next step, and the concept of a variable, i.e., the use of “named” locations to store and change the results of a computation. The EDVAC design included a processing unit, a control unit, memory to store both data and instructions, external mass storage, and input/output mechanisms.
The following video provides the highlights of von Neuman’s architecture.

22. Click here to see Neumann’s video
John von Neumann ( )
First to propose the architecture for a Stored Program Electronic Digital Computer
Click here to see Neumann’s video

23. Turing III: Automatic Computing Engine (ACE) Report (Dec 1945)
Also a Founder of Artificial Intelligence
Designed Code Breaking Computers during WW II
Created the Design for ACE (1945), proposing
A Stored Program Electronic Computer
With Binary Arithmetic
Using Electronic Logic Circuits
ALU, Memory (and Registers) and I/O
Stored Program
Conditional Branching
Floating Point
Commercialized by Ferranti and
English Electric in 1950s
The third contribution of Turing came in 1945 in the form of a proposal to create an automatic computing engine, the ACE. After WWII, Turing was asked by the National Physical Labs to design an automatic computing engine. He had access to von Neumann’s EDVAC Report published earlier that year. He was already familiar with some of the basic ideas of the EDVAC report such as processor-memory-switch architecture, binary arithmetic and the concept of a stored program. And he rejected other elements of the design which he deemed to be brute force and instead proposed a simpler hardware structure analogous to today’s RISC architectures. In their paper titled “The Other Turing Machine”, Carpenter and Doran show that Turing’s design had many original concepts which were subsequently seen to be seminal to computer architecture. Perhaps these were the result of his extensive experience in designing special purpose code breaking computers during the war.

24. Cambrian Explosion of Computers List of Stored Program Computers 1946-1950
Manchester SSEM (UK)
CRT memory Jun-48 Binary
Modified ENIAC (US)
Read Only Memory Sep-48 Decimal
Cambridge EDSAC (UK)
Mercury delay line memory May-49 Binary
Manchester Mark 1 (UK)
CRT and magnetic drum memory Oct-49 Binary
Pilot ACE (UK)
Mercury delay line memory May-50 Binary
Also CSIRAC, BINAC, UNIVAC, SEAC, Harvard MarkIII
Soon after the EDVAC Report, beginning 1946, we began to see a Cambrian explosion in the evolution of computers, resulting in numerous successful attempts along the lines of von Neumann architecture.
Those of you interested in more detailed descriptions of my brief review may wish to refer to several important books on the subject by Brian Randall, Martin Davis, Jack Copeland and Jane Smiley.

25. Who was the First?
Babbage: FIRST to design a PROGRAMMABLE general purpose computer
Not implemented, No Impact
Atanasoff: FIRST to develop a working ELECTRONIC digital computer with binary arithmetic
Not a programmable general purpose computer
In spite of familiarity with Babbage’s work, did not see programmability as a central issue
Zuse: FIRST to develop a WORKING programmable general computer with binary and floating-point arithmetic
Not Electronic, No conditional execution
Turing I (1936): FIRST to propose the STORED PROGRAM CONCEPT (as part of Universal Turing Machine)
No implementation, No direct impact
Babbage’s Analytical Engine was the first general purpose programmable digital computer. However, there was no working prototype and it had little impact in the subsequent evolution of the modern digital computers.
Atanasoff-Berry Computer was the first electronic digital computer and the first to use binary arithmetic, but it was a fixed function, special purpose computer and was not programmable. Atanasoff was familiar with Babbage’s work, but apparently did not realize the value of a general purpose programmable concept embodied in Babbage’s design.
Zuse’s Z3 was the first working programmable general purpose digital computer and first to use binary and floating point arithmetic, but it was not electronic and it did not permit conditional execution and iteration. Zuse was not familiar with Babbage’s work or any other recent attempts. While a brilliant original thinker in many ways, Zuse apparently did not appreciate the importance of conditional execution and iteration in programs.
Turing was the first to propose, in 1936, the programmable computer and the stored program computer. Perhaps we should say that Turing re-discovered these concepts, since both of these features were anticipated by Babbage. It is not clear that Babbage fully appreciated the import of these aspects of his design. Turing also used binary representation of data.

26. Who was the First?
Turing II (1940): FIRST to be used for Symbolic Computation and Parallel Computation
Special purpose computer for code-braking
Flowers (1944): FIRST working Programmable ELECTRONIC digital computer
Not stored program, but just plug-board programming
von Neumann: FIRST to propose the STORED PROGRAM ELECTRONIC DIGITAL COMPUTER
widely adopted in US, many variations implemented, including EMCC and IBM
Turing III (1945): FIRST to anticipate a RISC ARCHITECTURE for a programmable electronic computer
ACE architecture used in English Electric and Ferranti Computers   
Turing was the first to make extensive use of automatic symbolic computation and parallel computation, in the code braking task. He was anticipated by Jacquard which weaved images stored on punch cards and Hollerith who invented sorting of data on punch cards.
Flowers was the first to use electronic components for a programmable computer.
Von Neumann was the first to propose the architecture for a stored program electronic digital computer. It was widely adopted in the US and around the world. The key components of von Neumann architecture continue to be used even today. Most modern computers have a processing unit and a control unit and memory to store both data and instructions, external mass storage and mechanisms for input and output. Many variations were implemented, including commercial versions by IBM and EMCC.
Turing was the first to propose, in 1945, a simpler hardware structure analogous to today’s RISC architectures for a programmable digital computer. The resulting ACE architecture was used in several early computers built in the United Kingdom and was the basis of successful commercial implementations used in English Electric and Ferranti computers. My own introduction to computing in the late 50s was to a machine based on Turing’s ACE architecture. Interestingly, these machines were still using mercury delay line memory. Core memory and semi-conductor memories had not yet arrived on the scene.

27. Who is the Inventor of Modern Computer?
Pascal, Leibniz, Stibitz, Aiken, Flowers, Eckert and Mauchly?
Babbage?
Atanasoff?
Zuse
Turing?
von Neumann?
Now we come to the question of which of the ten pioneers we talked about gets the most credit?

28. Relative Contributions of Various Pioneers
Name
System
Year
Programmable
Elec-tronic
Bi-nary
FloatPt
Stored
Prog
Prototype
CISC/ RISC
Impact Wide Use
Rank
Pascal
Pascaline
1645 N Y 7
Leibnitz
Pinwheel
1670
Stibitz
BTL
1936
Babbage
Analytc Engine
1840 6
Aiken 5
Atanasoff
ABC
1937
Turing II
Bombe
1942
Turing I
Turing Machine 4
Eckert & Mauchly
ENIAC
1940
Flowers
Colossus
1944 3
Zuse Z3
1941 2
von Neumann
EDVAC
1945 1
Turing III
ACE
To identify the relative contributions of various pioneers of the modern digital computer, I created a matrix with some of the salient features of a computer.
Was it Programmable?
Was it Electronic?
Did it use Binary arithmetic?
Did it use Floating Point?
Did it use store Programs as Data?
Was there a working Prototype?
Did it use simplified instruction Set (RISC)? and
Did it have any impact on Society?
I don’t expect you to be able to read all the fine print but I’ll walk you through the individual contributions and limitations quickly. Here I will use just four of these criteria to narrow the field of claimants to the title.

29. Programmable? Name System Year Programmable Elec-tronic Bi-nary
FloatPt
Stored
Prog
Prototype
CISC/ RISC
Impact Wide Use
Rank
Pascal
Pascaline
1645 N Y 7
Leibnitz
Pinwheel
1670
Stibitz
BTL
1936
Babbage
Analytc Engine
1840 6
Aiken 5
Atanasoff
ABC
1937
Turing II
Bombe
1942
Turing I
Turing Machine 4
Eckert & Mauchly
ENIAC
1940
Flowers
Colossus
1944 3
Zuse Z3
1941 2
von Neumann
EDVAC
1945 1
Turing III
ACE
The first criterion of programmability eliminates Pascal, Leibniz, Stibitz, Atanasoff and Turing II. Systems by Pascal and Leibniz were just calculators, whereas Systems built by Stibitz, Atanasoff and Turing II were capable of automatic execution of a sequence of steps and are examples of non-programmable fixed function computers.

30. Stored Program? Name System Year Programmable Elec-tronic Bi-nary
FloatPt
Stored
Prog
Prototype
CISC/ RISC
Impact Wide Use
Rank
Pascal
Pascaline
1645 N Y 7
Leibnitz
Pinwheel
1670
Stibitz
BTL
1936
Babbage
Analytc Engine
1840 6
Aiken 5
Atanasoff
ABC
1937
Turing II
Bombe
1942
Turing I
Turing Machine 4
Eckert & Mauchly
ENIAC
1940
Flowers
Colossus
1944 3
Zuse Z3
1941 2
von Neumann
EDVAC
1945 1
Turing III
ACE
The second criterion of representing and storing programs as data eliminates Eckert and Mauchly, and Flowers. They used a wired plug board to specify the sequence of operations.
Aiken, Babbage, Turing and Zuse represented programs as data stored on physical media such as paper tape, punch cards or mercury delay line memory. Von Neumann understood the need for rapid access to programs and the centrality of the stored program concept and highlighted it in the EDVAC report.

31. Binary Arithmetic? Name System Year Programmable Elec-tronic Bi-nary
FloatPt
Stored
Prog
Prototype
CISC/ RISC
Impact Wide Use
Rank
Pascal
Pascaline
1645 N Y 7
Leibnitz
Pinwheel
1670
Stibitz
BTL
1936
Babbage
Analytc Engine
1840 6
Aiken 5
Atanasoff
ABC
1937
Turing II
Bombe
1942
Turing I
Turing Machine 4
Eckert & Mauchly
ENIAC
1940
Flowers
Colossus
1944 3
Zuse Z3
1941 2
von Neumann
EDVAC
1945 1
Turing III
ACE
The third criterion of using binary arithmetic eliminates Babbage and Aiken.

32. Working Prototype? Name System Year Programmable Elec-tronic Bi-nary
FloatPt
Stored
Prog
Prototype
CISC/ RISC
Impact Wide Use
Rank
Pascal
Pascaline
1645 N Y 7
Leibnitz
Pinwheel
1670
Stibitz
BTL
1936
Babbage
Analytc Engine
1840 6
Aiken 5
Atanasoff
ABC
1937
Turing II
Bombe
1942
Turing I
Turing Machine 4
Eckert & Mauchly
ENIAC
1940
Flowers
Colossus
1944 3
Zuse Z3
1941 2
von Neumann
EDVAC
1945 1
Turing III
ACE
The fourth criterion of a working prototype eliminates Turing I (1936) proposal. Turing never intended to build a working system.
Of all the early pioneers, only Konrad Zuse had a working prototype that got most of the elements of a computer correct before He was the first to use binary arithmetic and floating point representation in a computer design. This is all the more remarkable since he was working in complete isolation.

33. Impact on Society Commercial Availability
Name
System
Year
Programmable
Elec-tronic
Bi-nary
FloatPt
Stored
Prog
Prototype
CISC/ RISC
Impact Wide Use
Rank
Pascal
Pascaline
1645 N Y 7
Leibnitz
Pinwheel
1670
Stibitz
BTL
1936
Babbage
Analytc Engine
1840 6
Aiken 5
Atanasoff
ABC
1937
Turing II
Bombe
1942
Turing I
Turing Machine 4
Eckert & Mauchly
ENIAC
1940
Flowers
Colossus
1944 3
Zuse Z3
1941 2
von Neumann
EDVAC
1945 1
Turing III
ACE
The final criterion of the impact on society leaves us with von Neumann and Turing as potential claimants for the title Inventors of the Computer.
In spite of being one of the first, Zuse’s designs had no impact on society or on the emergence of the digital computer industry, in part because of the conditions in Germany after WWII.
Von Neumann clearly had many of the key concepts correct. The wide distribution of his EDVAC Report ensured that his design was the primary architecture most computers used for many decades to come.
Many of the ideas in Turing’s ACE Report have been demonstrated to be seminal and central to the current practice of computer design. For example, given his code breaking experience of World War II, he understood the centrality of symbolic computing and the primacy of software over hardware. He specifically made the hardware simple and easy to implement at low cost with a view that software can take care of all the complex operations. This foretold the primacy of RISC architectures which were only taken seriously in recent years, after many decades of the supremacy of the CISC architectures. Today, the ARM processor, a low power RISC architecture, which originated in England, is widely used in Smart Phones and Tablets representing over 90% of all microprocessors used annually. .

34. In Summary
Babbage got most of the elements of a Digital Computer right
No impact
Jane Smiley thinks Atanasoff invented the computer
But it was not a general purpose programmable architecture
had no impact on the future evolution
Martin Davis believes that Turing qualifies for the title given the 1936 seminal paper
but the Universal Turing Machine idea was largely ignored
had little impact on the emergence of the modern computer
Zuse got most of the elements right
based on electromechanical components, and
no conditional execution
von Neumann or Turing?
This is like asking who invented calculus: Newton or Leibniz?
EDVAC and ACE reports defined the future of Computing
So who invented the computer? I believe that given adequate resources and time, any one of the five listed in my title, would have invented the seminal aspects of the modern computer.
Babbage got most of the elements of a Digital Computer right but was 100 years ahead his time and had no impact.
Jane Smiley credits Atanasoff with the invention of the computer, primarily because he was the first to design and build an electronic computer. Unfortunately, Atanasoff’s design was not a general purpose programmable architecture and had no impact on the future evolution of the modern computer.
Martin Davis believes that Turing qualifies for the title given the Turing’s 1936 seminal paper. However, the Universal Turing Machine was merely an abstract digital computer concept and it was never intended to be implemented as a working prototype. Turing’s paper was largely ignored and had little impact on the emergence of the modern computer.
The fact that Zuse’s implementation did not permit conditional and iterative execution, makes it clear that he did not fully appreciate the requirements of programmability at that time. But, given another year of uninterrupted time and resources, he might have discovered the need for conditional execution much as Lady Lovelace did while programming Babbage’s Analytical Engine.
So is it von Neumann or Turing? This is like asking who invented calculus: Newton or Leibniz? EDVAC and ACE reports did define the future of computing.

35. Who Invented the Computer
Who Invented the Computer? Babbage, Atanasoff, Zuse, Turing or von Neumann?
All of them deserve the title
“Man Who Invented the Computer”
It is amazing and inspiring that these pioneers working alone and in isolation with limited resources made as much progress
I believe that each one of them deserve the title “Man Who Invented the Computer”
It is amazing and inspiring that these pioneers working alone and in isolation with limited resources made as much progress as they did. So, in my view all five deserve the title, “The man who invented the computer”

36. Post 1945 The dawn of Computer Age? Progression from
Advances over last 7 decades: incredible and unprecedented in the annals of science and technology
exponential growth in computational power,
exponential growth in memory capacity,
exponential growth in optical bandwidth and
exponential growth in wireless bandwidth.
Progression from
transistors to integrated circuits to vlsi to multicore
mainframes to minis to pcs to mobile systems to warehouse scale computers
Arpanet to Internet to Wifi to 4G to gigabit wireless
Interpreters to compilers to www to apps
We stop this narrative at the end 1945, at the dawn of the Computer age. Advances over the last 7 decades have been incredible and unprecedented in the annals of science and technology. We have had exponential growth in computational power, memory capacity, optical bandwidth and in wireless bandwidth. We have seen progression from transistors to integrated circuits to VLSI to multicore chips; from mainframes to minis to pcs to mobile systems to warehouse scale computers; from Arpanet to Internet to Wi-Fi to 4G to gigabit wireless; and from Interpreters to Compilers to WWW to Apps.

37. Post 1945 (cont)
Most importantly, we have expanded the scale and scope of the uses of computers by developing algorithms for many unconventional tasks such as
cars that drive themselves
any-to-any language translation
spoken language understanding
winning at games such as
poker, robo-soccer, jeopardy
winning and crashing the stock market
Derivatives market
Cause sub-prime financial crisis
These are tales for another day!
Most importantly, we have expanded the scale and scope of the uses of computers by developing algorithms for many unconventional tasks such as autonomous cars, language translation, spoken language understanding and competing in games such as chess, poker, robo-soccer and jeopardy.
Finally, our computers have also succeeded in destabilizing the stock market! Sigh!
These are tales for another day! Thank you.