After college, I served in the antiaircraft troops for two years, advancing to lieutenant. The gun-sight director that I had to operate was an electromechanical analog computer. It interested me considerably, I studied its intricate mechanism in depth, and, accordingly, I could serve as an instructor to my colleagues. This was my first contact with computing.

Stiefel was quite well-informed about the current state of the art, although he had personally never seen a digital computer. I told him what I had observed in Wilkes's department, I outlined the concept of the von Neumann machine (although this name was not in use at that time), and I was pleased to observe that Stiefel showed considerable interest. He explained that he planned to send two assistants to the United States for a year in order to familiarize themselves with computer technology; after their return, they would build a computer for ETH, since commercially available machines for mathematical purposes did not exist and were not in the foreseeable future.

All these specifications of the Z4, as seen in 1949, were very convincing for Stiefel, Rutishauser and Speiser. It must be borne in mind that at this time there were hardly a dozen program-controlled computers in operation, all of them in US. Less than a handful were in use for research in numerical mathematics, the others performed routine calculations. There were no doubts that Z4 could be used for serious mathematical research. ... When the Z4 machine was installed, significant work started almost immediately. Within a few years Zürich rose to be one of the foremost centres in numerical analysis. ... The creative spirit that was ever-present, the continuous expression and evaluation of new ideas, the thoroughly based academic knowledge and the sound scientific judgment were daily realities, I am almost tempted to say: This was the air that we were breathing. I can hardly believe, that Stiefel, when he decided to acquire the Z4, would have dared to hope for success of this degree! The Z4 was also extensively used in education. As early in 1951, we offered to students a course in computer programming with practical exercises on the machine. We believe we were the first on the European continent to do so. This should be taken in consideration by those who often criticize that Swiss Universities were late in recognizing the importance of informatics.

... the author gives a quite complete account of an electronic digital computer, being considered by the computation laboratory at the Technical Institute in Zürich. The machine is to have a magnetic drum memory of 1200 word capacity, each word being 12 decimal digits. The multiplication speed is 30 ms. and the average access time to the memory is 16 ms. The author gives a comprehensive discussion of all relevant mathematical phases of the problem as he poses it. This is to construct a low cost, rapid machine for a modest size computation laboratory. The machine described is to have about 1000 vacuum tubes and 300 relays.

In this series of papers the authors discuss in very considerable detail a number of the important mathematical questions that naturally arise in the design of a digital computer. These topics include possible number systems, the questions of "fixed" vs "floating" point and complementation, the arithmetic processes, the grouping of numbers to achieve higher than normal precisions, conversion between number systems, the structure of finite approximation methods, error analysis, programming and coding as well as the physical organs of a machine. In many of these considerations the authors have compared the various points of view expressed by others in the field to give a comprehensive picture of the situation as understood at the present time.

The advice to talk to my father before contacting me was, indeed, unusual. Evidently, Samuel and my father had agreed to keep their meeting confidential -- I learned about it only many years later through a casual remark by my father, but, of course, I did not resent it in the least. But, one point is worth mentioning: When the offer from IBM came in 1955, I almost simultaneously received an offer for employment from a Swiss company that looked quite interesting. I asked my father what he thought about it. He encouraged me to decide for IBM.

By 1966, the laboratory had well-established itself in the new building. Research management did not anticipate further growth, at least for the coming few years.

In 1966, I decided to make a complete change in my life and to accept the position of Director of Corporate Research of Brown Boveri, a large international corporation based in Switzerland, active mainly in the electric power field. Accordingly, steam turbines and electric generators, rather than computers, became the objects of my daily work.