“The Best Way to Design . . .”

In February 1951, the Ferranti Mark I was delivered to the University of Manchester. This was the commercial “edition” of the Manchester Mark I (see Chapter 8, Section XIII), the product of a collaboration between town and gown, the former being the Manchester firm of Ferranti Limited. It became (by a few months) the world’s first commercially available digital computer (followed in June 1951 by the “Universal Automatic Computer” [UNIVAC], developed by the Eckert-Mauchly Computer Corporation). The Ferranti Mark I was unveiled formally at an inaugural conference held in Manchester, June 9 to 12, 1951. At this conference, Maurice Wilkes delivered a lecture titled “The Best Way to Design an Automatic Calculating Machine.” This conference is probably (perhaps unfairly) more known because of Wilkes’s lecture than for its primary focus, the Ferranti Mark I. For during this lecture, Wilkes announced a new approach to the design of a computer’s control unit called microprogramming, which would be massively consequential in the later evolution of computers. Wilkes’s lecture also marked something else: the search for order, structure, and simplicity in the design of computational artifacts; and an attendant concern for, a preoccupation with, the design process itself in the realm of computational artifacts. We have already seen the first manifestations of this concern with the design process in the Goldstine-von Neumann invention of a flow diagram notation for beginning the act of computer programming (see Chapter 9, Section III), and in David Wheeler’s and Stanley Gill’s discussions of a method for program development (Chapter 10, Section IV). Wilkes’s lecture was notable for “migrating” this concern into the realm of the physical computer itself. We recall that, in May 1949, the Cambridge EDSAC became fully operational (see Chapter 8, Section XIII). The EDSAC was a serial machine in that reading from or writing into memory was done 1 bit at a time (bit serial) ; and, likewise, the arithmetic unit performed its operations in a bit-by-bit fashion. Soon after the EDSAC’s completion, while others in his laboratory were busy refining the programming techniques and exploring its use in scientific applications (see Chapter 9, Sections V–VIII; and Chapter 10), Wilkes became preoccupied with issues of regularity and complexity in computer design and their relation to reliability.