Class today began with a short feedback session, in which we filled out short notes stating something we thought was going well in the class, and something that we thought could be improved.
From there we jumped stright into sharing interesting quotes and passages from the reading, “Johnny Builds Bombs and Johnny Builds Brains”. Topics of favorite quotes were very diverse: how von Neumann managed to win vast amounts of financial support from the government, likely due to his charisma and well-placed connections (rather unlike our old friend Babbage); the somewhat lucky rise of Mauchly and Eckert, and their fortuitous partnership with Goldstine, who had grown increasingly frustrated with army policies; von Neumann’s diverse and rather charmed existence, with his intellectually star-studded parties and major contributions to the fields of game theory, quantum physics, operational research (and later life itself and the construction of automata, to be called von Neumann machines); and finally the mess about who came up with which ideas first during this period of extremely rapid innovation.
This last topic started the discussion over rights and patents during this period. This started with the innovation of the stored program (and the infamous First Draft which lead many to give the credit solely, and perhaps unjustly, to von Neumann, who likely put only his name on the manuscript because it was only the draft version), as well as the arguments between von Neumann and co.’s ENIAC machine and Atanasoff and Berry’s ABC. The disagreement stemmed from a short visit by Mauchly to Atanasoff, where the exchange of ideas eventually leading to construction of the ENIAC may or may not have taken place While that disagreement was “solved” by Minnesota courts in 1973 (in favor of the ABC), discussion is still ongoing and unclear about who was responsible for which ideas during this time of extremely rapid innovation.
Discussion then flowed into an attempt to organize the figures and machines that took part in the computer revolution. What we came up with as a class was sort of a mish-mash of connected events and tangled ideas; however, this disarray was actually reflective of the time, in which many people were sharing ideas with others, as well as coming to similar conclusions through independent work. Dr. Wagstaff has graciously organized this information by hardware technology and chronologically:
1. Mechanical computers: Differential Analyzer (1931)
2. Electromechanical computers: Z3 (1941), Harvard Mark 1 (1944)
3. Electronic computers:
– ABC (1942, first vacuum tube logic, 300 tubes, binary representation, not programmable)
– Colossus (1944, 1500 tubes, limited programming with cables)
– ENIAC (1946, 18,000 tubes, decimal representation, programmed with cables)
– EDSAC (1949, Cambridge, 3000 tubes, binary, first stored program, using mercury delay line memory)
– Manchester Mark 1 (1949, first stored program, using cathode ray tube memory)
– ACE (1950, 1450 vacuum tubes, mercury delay line memory, 1 MHz)
– EDVAC (1951, 6,000 tubes, mercury delay lines)
– UNIVAC (1951, 5,200 tubes, mercury delay lines, first commercially available computer in US)
A bit more detail can also be found on this Wikipedia page, which includes a fully chronological table of events from the 1940’s. There were also several theoretical constructs included in this discussion, including self-replicating von Neumann machines, universal Turing machines, and how one could turn a Turing machine into a von Neumann machine by adapting the Turing machine’s output with a robotic construction device.
As for the figures, we discussed how the various groups formed and influenced one another. This ends up being somewhat of a web, so I shall arbitrarily choose Turing as our starting point. Turing made his initial contributions while at Princeton studying under Church, a mathematical logician. It was here that he initially came into contact with von Neumann, a student of Hilbert’s, though the contact didn’t foster much in the way of later partnerships; Turing returned to England to aid with code breaking during the war, and later drew up the plans for ACE. ACE was eventually built after Turing left the NPL (at the time the fastest computer in the world at 1 MHz), while Turing oversaw the construction of the Manchester Mark I. On the other side of the pond, von Neumann joined with Goldstine, Mauchly and Eckert in efforts that eventually lead to construction of the ENIAC (and this group’s interactions with those that constructed the ABC have been mentioned earlier), which later blossomed into the EDVAC. Other somewhat more independent mentions were Aiken, who was responsible for the Harvard Mark I, and the group at MIT who constructed the Differential Analyzer.
And, finally, any discussion mentioning von Neumann machines would be incomplete without the thoughts of philosopher Randall Munroe.