IBM 7074 and then some: "Systems we love" conference

On Wed, Jan 25, 2017 at 8:07 PM, Chuck Guzis <cclist at sydex.com> wrote: That's certainly more convincing, but it still seems to be a bit of a mystery. The four authors of IBM's Early Computers were all engineers and engineering managers intimately involved with the development of the computers in that time frame, were researchers at IBM when the book was written, and based much of the book on material from IBM archives. I could imagine them getting a date wrong, but it seems pretty surprising that they would specifically claim that the 7070 was announced far before the 7090 but shipped six months after, if that wasn't true. IBM generally didn't consider a data processing system to have "shipped" until it passed the field acceptance criteria, e.g., assembled on-site and passed diagnostics. Perhaps the 7070 didn't pass acceptance testing until April 1960?