Hello everyone, I've had a chance to read carefully through chapters 2 and 3 on Isaacson, on the invention of the computer and the origin of programming. One striking thing is how detailed much of this narrative is, and how many obscure Annals papers he cites. So it is clear that he has done a lot of reading and digging into secondary sources. For a mass market book it's unusual even have endnotes, and certainly (to make sure that nobody confuses to two recent discussion threads) I see no reason for concern over plagiarism. He is interested in some very traditional, very detailed questions on the history of early electronic computing. In particular in assigning credit between the various inventors of early machines. Although he cites a lot of our work he presents his own interpretations of who did what, what was the true "first computer," etc. So there are many pages on ENIAC, the ABC, the "First Draft" and those other traditional topics. The book is more nuanced in some areas than the things he says in interviews, and much of it is clearly written and strikes me as accurate. It's precisely because he has spent so much time with our work, and presented his book with the apparatus of scholarly research, that I am startled to see that he got so many things wrong. I counted 32 things in those two chapters that struck me as errors or misleading assertions, from the claim that ENIAC was never used to calculate tables to the idea that its initial program run from December 1945 onwards (which he dates to October) disproved Teller's design for a hydrogen bomb. Most of those are minor things. Here's the big one. In returning to these old questions of invention and credit, Isaacson naturally has to address one of the thorniest questions of all: how did thinking on computer design evolve between January 1944, at which point Eckert and Mauchly were already speculating about post-ENIAC computer designs and storage mechanisms, and April 1945 when Goldstine's received from von Neumann the "First Draft of a Report on the EDVAC." We know that von Neumann started to work with the ENIAC team in August 1944, and that the "First Draft" was the first statement of the key ideas behind modern computers. The extent to which von Neumann created those ideas versus stealing the existing work of the ENAIC team has been much debated. The problem historians face is that the participants spent the next few decades on opposing sides of a long and bitter lawsuit, making oral histories and memoirs more than usually problematic. Primary sources are very thin for that whole period - a few letters, the sketchy minutes of four meetings in early 1945, von Neumann's travel plans, and some technical disclosures by Eckert and Mauchly of ideas on memory technologies and a disk or drum calculator. A careful look at the meeting minutes tells one mostly about what had not been settled on (like the dog that didn't bark). They don't mention instruction sets, record disagreement on some basic architectural options, and are focused mostly on memory technology. This, at the least, keeps the door open for one to conclude that von Neumann designed the proposed EDVAC instruction on his own while away from the Moore School and that he had an important solo role in compressing a range of options under consideration during the Moore School meetings into a coherent architecture of radical simplicity. Isaacson described the Spring 1945 meetings between von Neumann and the ENIAC team in far more detail than any previous account. He does mention the minutes, which is impressive as they are rather obscure. However, his main source on what was discussed and how they were conducted is the recently published memoir of Jean Bartik. Isaacson uses some lengthy quotes from her to show that von Neumann led detailed discussion of a proposed instruction set but welcomed the input of others, including Bartik who made a technical point that he ultimately accepted. That fits Isaacson's interests in rescuing "forgotten" women and to celebrating the collaborative nature of innovation. The problem: Bartik was not at those meetings. She had just begun training as a human computer but was not yet part of the ENIAC team. Her quotations describe an entirely set of meetings, held in Princeton three years later with an almost entirely different group of people. Those meetings were to define an instruction set for ENAIC once it was converted to the EDVAC-mode of programming I like to call the "modern code paradigm." It's clear from her narrative that these meetings are taking place in 1947 so this is a very odd mistake to make. That's the biggest and strangest error I noticed, and I expect it will jump out at any reader with a reasonable knowledge of the history of 1940s computing. I also formed the distinct impression that Isaacson, despite spending quite a few pages on the "stored program concept" and the first stored program computer, does not really understand it (pardonable) or have his book read carefully by anyone who did (less pardonable). The traditional reading of "stored program" is that an externally programmed machine like the Harvard Mark I fetches and executes instructions one at a time from a paper tape or other external medium. A stored program computer like EDSAC or EDVAC loads the whole program into memory (i.e. stores it) before beginning execution, which allows jumps etc. within the code sequence. The phrase has been burdened with many other meanings, but that's the core. In a section headed "Stored Programs" Isaacson introduces the stored program idea by writing that "as early as the beginning of 1944, Mauchly and Eckert realized that there was a good way to make computers more easily reprogrammable: store the programs inside the computer's memory rather than load them in every time." In that framework a computer with a hard drive or ROM is "stored program," but a computer like EDSAC where the program is read into memory from paper tape before being run would not be. A separate statement on the Harvard Mark I also suggests that he imagines that computer loaded a program from tape rather than executing a individual instructions from tape: "Even though the paper tape was useful in reprogramming the computer it was necessary to switch tapes manually every time there was a call for a subroutine". Best wishes, Tom