1. History of the Digital Computer through 1951

2. George Boole ( )
English mathematician and logician, son of a cobbler
First Professor of Mathematics at Queens College in Cork
Author of The Laws of Thought
Invented Boolean Algebra

3. Claude Shannon ( )
Learned about Boole’s work as an undergraduate at U. Michigan
1937 Masters thesis “A Symbolic Analysis of Relay and Switching Circuits”
Wrote seminal “A Mathematical Theory of Communication”
First published use of the term “bit” (for binary digit)

4. Appreciating Claude Shannon (0-4:58)

5. Vannevar Bush and the Differential Analyzer
The Differential Analyzer was an analog machine to solve differential equations
Completed in 1931 by Vannevar Bush and Harold Hazen
Mostly mechanical, part electrical
Claude Shannon hired in 1936 to run the analyzer

6. Computer Pioneers Video 2:15 – 4:12

7. Alan Turing ( )
1937 Wrote “On Computable Numbers” to solve Hilbert’s Entsheidungsproblem – describing the Turing Machine
1939 Developed the “Bombe” at Bletchley Park to decode Enigma messages
Postulated “Turing Test” for artificial intelligence

8. Turing Machines
Never meant to be built. Designed to solve theoretical problems.
A Turing machine has an embedded state table (a program) to read and manipulate symbols on a tape of arbitrary length
Universal Turing Machine: "It is possible to invent a single machine which can be used to compute any computable sequence. If this machine U is supplied with a tape on the beginning of which is written the S.D ["standard description" of an action table] of some computing machine M, then U will compute the same sequence as M."

9. The Bombe – electromechanical Enigma solver

10. Turing Machine video 0:0 to 4:18

11. George Stibitz (1904-1995) Worked at Bell Labs
Built a relay-based binary calculator in his kitchen in 1937
Subsequently built increasingly complex models at Bell Labs.
Completed a programmable, general-purpose relay computer in 1946
Invented the term “digital”

12. Konrad Zuse (1910-1995) Frustrated by aircraft calculations.
Built world’s first programmable (via tape) fully operational computer.
Earliest versions were built in his parent’s house with no funding.
Eventually got some support from an aircraft company. Was turned down by the Nazi government.

13. Rebuild of Zuse’s Z3 Computer

14. John V. Atanasoff (1903-1995) Taught at Iowa State University
Thought of key principles of a computer on a long drive
With Clifford Berry (graduate student assistant), built a 600 vacuum tubes machine to solve simultaneous linear equations
Drafted for a Naval Ordinance Lab assignment in 1942, before completing the machine
Federal judge declared him the inventor of the electronic digital computer

15. Reconstructed Atanasoff-Berry Computer (0-5:30)

16. Howard Aiken (1900-1973) Son of abusive, alcoholic father
While working on his physics PhD at Harvard, had tedious calculations for numeric approximation of differential equations.
Was inspired by Charles Babbage.
With IBM, built Mark 1 relay computer at Harvard. Had Navy funding, completed in
Later built Mark II, III, IV. Mark IV was all electronic.

17. IBM Harvard Mark 1 or Automatic Sequence Controlled Calculator

18. Tommy Flowers (1905-1998) and Colossus
1926 joined the telecom branch of the General Post Office
1935 began exploring use of electronics for telephone exchanges
Proposed for Bletchley work by Alan Turing
Chief designer (with mathematician Max Newman) of Mark 1 (1,500 tubes) and Mark 2 (2,400 tubes) Colossus to solve Lorentz code quickly
Had to overcome opposition to use of vacuum tubes (instead of relays).

19. Colossus Project :20-5:00

20. “Flowers later described a crucial meeting between Dwight D
“Flowers later described a crucial meeting between Dwight D. Eisenhower and his staff on 5 June, during which a courier entered and handed Eisenhower a note summarizing a Colossus decrypt. This confirmed that Hitler wanted no additional troops moved to Normandy, as he was still convinced that the preparations for the Normandy Landings were a diversionary feint. Handing back the decrypt, Eisenhower announced to his staff, "We go tomorrow." Earlier, a report from Field Marshal Rommel on the western defences was decoded by Colossus and revealed that one of the sites chosen as the drop site for an US parachute division was the base for a German tank division. The site was changed.”

21. Colossus Rebuild

22. ENIAC – J.Presper Eckert (1919-1995) and John Mauchly (1907-1980)

23. John Mauchly Physics instructor, Ursinus College
Worked on problems of weather prediction
Attended a wartime course on electronics at Moore School
Attended AAS meeting December 1940 and met John V. Atanasoff of Iowa State Univ.
Visited Atanasoff in Iowa, June 1941
Wrote proposal “The Use of High Speed Vacuum Tube Devices for Calculating” August 1942 at the U. Of Pennsylvania (ignored!)
Thomas Bergin, Computing Museum, American University

24. J. Presper Eckert
Met John Mauchly while a graduate student supervising laboratory work for a war-time electronics class 1941
Did wartime research on radar and delay line memories for radar devices
Chief Engineer on ENIAC; contract signed when he was 24 years old
“...we called worst-worst design...” (to design components so that they could operate out of tolerance or specification)
prior testing and burning in of tubes
modular construction for ease of maintenance - individual units which slid in and out
Thomas Bergin, Computing Museum, American University

25. Herman Goldstine (1913-2004) U. of Chicago Ph.D.
Assistant Professor of Mathematics before war
Assigned to BRL (Ballistic Research Laboratory), as a 2nd Lieutenant because he had a course in ballistics
Oversaw U Penn efforts to calculate firing tables using manual methods
Heard about Mauchly’s interest in computation
Arranged a meeting for April 1943 to discuss a possible contract with the Army
Thomas Bergin, Computing Museum, American University

26. ENIAC – Electronic Numeric Integrator And Computer
Built at Moore School, U. of Penn
Mauchly architect, Eckert chief engineer
Funded by US Army to calculate ballistic firing tables
Mauchly’s proposal in 1942 was ignored until Herman Goldstine saw it in March 1943 and realized its significance
Work started in late 1943, not completed in time for WW II
Employed for computation for H-bomb design
Most ambitious and fastest computer constructed up to then: 18,000 vacuum tubes, 70,000 resistors, 10,000 capacitors. Weighed 30 tons.
Programmable, with difficulty, by patch cables and switches. No ability to make logic decisions based on numeric results.

27. Audacity of the ENIAC project
When engineers build structures such as bridges and tall buildings, size improves cautiously!
– Build a 4 story building; next do a 6 story one
Largest electronic device at the time (a classified radar) contained 300 to 400 vacuum tubes.
ENIAC was to contain 18,000 vacuum tubes
Project criticized by just about all: size,reliability, etc. [fear of the unknown]
Thomas Bergin, Computing Museum, American University

28. Picture of the ENIAC

29. Programming the ENIAC
“Programming ENIAC was a one-way ticket to the madhouse. You did not sit down at a computer terminal and type in the instructions; instead, you set thousands of switches and plugged in hundreds of cables (like the cables on old telephone operator consoles) by hand, one at a time. In general, it took about two days to set up ENIAC to carry out a program.” “Since ENIAC was intended to calculate firing tables, no one foresaw the need for a convenient programming process; having set up the machine to compute one firing table, you only had to change a few switches and cables to process another table. ” Bit by Bit

30. Controversy
American Association for the Advancement of Science, Philadelphia, PA Dec.26, 1940
John Mauchly gives a lecture on calculation for weather predictions; Atanasoff is in audience.
Mauchly and Atanasoff talk after the lecture;
Atanasoff says he is building a calculating device; correspondence ensues.
Mauchly drives to Ames, Iowa in June 1941 to see the partially constructed ABC
June 26, 1947 Eckert and Mauchly apply for patent on the ENIAC which “embodies our invention....”
Thomas J. Bergin, Computing History Museum, American University

31. Programming the ENIAC

32. The ENIAC programmers
Frances Bilas
Jean Jennings
Ruth Lichterman
Kay McNulty
Betty Snyder
Marlyn Wescoff
Later, Adele Goldstine and Klara von Neumann
1945 Moore School ad:
Wanted: Women With Degrees in Mathematics…Women are being offered scientific and engineering jobs where formerly men were preferred. Now is the time to consider your job in science and engineering…You will find that the slogan there as elsewhere is WOMEN WANTED!

33. Admiral Grace Murray Hopper (1906-1992)
PhD in mathematics from Yale
Assoc. professor of math at Vasser
Joined Naval Reserve in 1943, assigned to the Navy computation project at Harvard under Howard Aiken.
Co-authored 3 papers on the Mark I.
Joined Eckert-Mauchly Computer Corp
Created world’s first compiler (for the Univac), and Flow-matic programming language, forerunner of COBOL.
Technical consultant to the COBOL effort.
Developed validation software for COBOL.

34. Grace Murray Hopper video

35. John von Neumann Born in Hungary, immigrated to US
Mathematician, physicist (quantum mechanics), applied mathematician
Appointed to Institute for Advanced Studies (IAS) at Princeton in 1933
Worked on Manhattan Project
Joined the ENIAC project in late after chance meeting with Herman Goldstine

36. EDVAC Electronic Discrete Variable Automatic Computer
Designed and constructed at Moore School as successor to ENIAC
Binary stored program computer
Project started even before ENIAC completion
Completion hampered by loss of key people.
The design document had more influence than the actual machine
Key designers included Eckert, Mauchly, John von Neumann
6000 vacuum tubes, mercury delay-line memory
Delivered to Army Ballistics Research Lab 1949, though not working reliably before 1951

37. Stored-program controversy
Eckert and Mauchly had conceived of the stored program long before von Neumann joined the effort.
However, Eckert and Mauchly had not gotten around to outlining a design for a stored program computer when von Neumann appeared.
Von Neumann crafted a proposed set of instruction codes and a logical design for EDVAC, the successor to the ENIAC. He recommended using binary arithmetic.
Von Neumann’s report was meant to be a draft that would later have the credits entered, but Herman Goldstine circulated it widely.

39. “Von Neumann” architecture

40. Moore School Lectures
“Theory and Techniques for Design of Electronic Digital Computers”
8 week course given at the Moore School in the summer of 1946
Disseminated the ideas developed for the EDVAC
Lectures given by Eckert, Mauchly, Goldstine, von Neumann, and others
28 invited students plus a few others, many from US government and military, some from academia
Most students from US, some from UK
Sponsored by Army Ordinance Dept. and Office of Naval Research

41. Alan Turing and the ACE
“The first scientist on Womersley’s [I. J. R. Womersley, an official of the National Physical Laboratory] staff was, fittingly enough, Turing. Charged with the task of developing the machine, Turing studied von Neumann’s paper and then wrote one of his own, a comprehensive plan for a large computer called ACE, or Automatic Computing Engine. (The “engine” in the name was a bow to Babbage.) ACE was an ambitious machine, with a memory of 204,800 bits and an operating speed of a million pulses a second – ten times faster than ENIAC.”

42. Alan Turing and ACE (cont.)
“Turing devoted a lot of attention to ACE’s programming, drawing up a roster of programs, composed in a partially numerical, partially alphabetical code, which were the first bona fide programs. But ACE became a victim of bureaucratic indecision and miscomprehension, and a drastically scaled down version, the Pilot ACE, was constructed instead. This machine was completed in May 1950, but by that time Turing, fed up by the timidity and indecision of the National Physical Laboratory, had escaped to Manchester University, where a more efficient computer project was underway.” Bit-by-Bit

43. ACE video

44. Manchester “Baby” Computer (SSEM)
Developed by a team at University of Manchester (UK), led by Tom Kilburn, with Frederick Williams and Geoff Tootill.
Used Williams cathode-ray tubes (invented by Fred Williams) for memory.
Intended as proof-of-concept for the new memory.
World’s first stored-program computer (June 1948).
Way station to the Manchester Mark 1 (1949).
Alan Turing wrote one of the first programs for the SSEM.

45. Manchester “Baby”

46. Manchester Baby video 0 – 2:50

47. EDSAC Electronic Delay Storage Automatic Calculator
Inspired by John von Neumann’s Report on the EDVAC
Constructed at University of Cambridge in England
Team led by Maurice Wilkes
In use from 1949 to 1958
Had a primitive assembler (software) in 1949, possibly the world’s first.
Supported by J. Lyons and Co., and gave rise to the LEO, the world’s first computer put into commercial use

48. EDSAC

49. Eckert-Mauchly Corp.
Eckert and Mauchly left U. Penn to start a company when told they could not patent their work while at U. Penn.
Eckert-Mauchly Corp. had an ambitious development project, but ran out of funds.
Purchased by Remington-Rand, later Sperry-Rand.
Developed UNIVAC computers. First delivery, 1951.
“Most companies, particularly IBM, didn’t take these machines seriously until Eckert and Mauchly had proved that there was indeed a sizable market for computers even at several hundred thousand dollars apiece.”
Sperry lost fight over its broad patent
EDVAC report had constituted prior publication
Judge ruled that it was derived from Atanasoff’s work

50. Univac I

51. Univac I operator’s console

52. Univac gains fame
Dorothy Fuldheim: Tell me, Walter, what are you going to do to report this very historic election?
Walter Cronkite: Well, this year [1952] we’ve got the same basic formula that we had before, which is, of course, straight reporting of how the returns are coming in. However, we do have a little gimmickry this year which I think is most interesting, and may turn out to be something more than gimmickry. We’re using an electronic brain which a division of Remington Rand has in Philadelphia.
Fuldheim: What does it do?
Cronkite: It’s going to predict the outcome of the election, hour by hour, based on returns at the same time periods on the election nights in and Scientists, whom we used to call long hairs, have been working on correlating the facts for the past two or three months…. Actually, we’re not depending too much on this machine. It may be just a sideshow… and then again it may turn out to be of great value to some people.

53. IAS computer Project of Institute for Advanced Study, Princeton
Under direction of John von Neumann
Julian Bigelow was chief engineer. Herman Goldstine and others were on the project.
Limited operation in summer of 1951, full operation in 1952.
“Plans for the IAS machine were widely distributed to any schools, businesses, or companies interested in computing machines, resulting in the construction of seventeen derivative computers referred to as "IAS machines," although they were not software compatible in the modern sense.”

54. Von Neumann with IAS machine

55. Short-sightedness
In retrospect, the proliferation of computers is easy to explain, although in the late 1940s most people – including many scientists who should have known better – were highly skeptical of the need for such machines. For example, in 1947, Aiken, a stubborn man who was then in the midst of building an electronic calculator without stored- program capability and who missed the technological boat in many other crucial ways, told two officials of the National Bureau of Standards (NBS), which was backing Eckert and Mauchly’s commercial efforts: “There will never be enough problems, enough work for more than one or two of these computers…. You two fellows ought to go back and change your program entirely, stop this… foolishness with Eckert and Mauchly.” Fortunately, the NBS ignored him.
Bit by Bit

56. Name
Inventor(s)
Country
Year completed
Technology
Binary or decimal
How controlled (programmed)?
Turing complete?
Notes
BTL 1
George Stibitz, Samuel Williams US
1939
electro-mechanical
binary
not programmable no
built at Bell Labs, first computing machine used remotely
Atanasoff-Berry Computer
John Atanasoff, Clifford Berry
, not completed
electronic
designed to solve simultaneous linear equations Z3
Konrad Zuse
Germany
1941
punched tape
yes
Destroyed in Allied bombing in 1944
Collosus
Tommy Flowers UK
1943
patch cables and switches
special purpose for breaking German codes
Harvard Mark I
Howard Aiken
1944
decimal
punched paper tape
Programmed by Grace Hopper Z4
1945
Became only the 2nd computer to be sold commercially
ENIAC
J. Presper Eckert, John Mauchly
1946
17,000 tubes. Used to calculate artillery firing tables, H-bomb design
Manchester "Baby"
Frederick Williams, Tom Kilburn, Jeff Tootill
1948
stored program
Possibly world's first true electronic stored-program computer. Used Williams-Kilburne storage tube to hold 2048 bits.
EDSAC
Maurice Wilkes
1949
based on EDVAC draft paper
Manchester Mark I
Frederick Williams, Tom Kilburn
EDVAC
Eckert, Mauchly, Von Neumann, others
limited use
Pilot ACE
Alan Turing, James Wilkinson, Harry Huskey
1950
Alan Turing was architect of "ACE" in A scaled-down version called "Pilot ACE" was built. First computer with floating point arithmetic.
MESM
Sergei Lebedev
USSR
6,000 vacuum tubes
IAS machine
John von Neumann, Julian Bigelow
1951 limited operation, 1952 full
Early parallel machine, gave rise to many others, including IBM 701
Ferranti Mark 1
Frederick Williams, Tom Kilburne
1951
World's first commercial stored-program computer. Based on Manchester Mark I.
UNIVAC 1
Eckert and Mauchly
First one delivered to Census Bureau
LEO (Lyons Electronic Office)
John Pinkerton, Derek Hemy
First computer for commercial applications. Based on EDSAC. Built for internal use by Lyons Co., later made into a product for sale.
IBM 701
Jerrier Haddad, Nathaniel Rochester
1953
Based on IAS machine. 18 sold, to aircraft companies, government agencies, universities, GE, GM

57. The problems of the early computers
Relays were slow
Vacuum tubes were big, used a lot of power, and were unreliable
Memory was very costly and thus very limited
Vacuum tubes
Cathode-ray tubes
Mercury delay lines