Facing up to Faults

After the war, Turing re-appeared on the public scene, so to speak, and was instrumental in initiating the work at the National Physical Laboratory (NPL) on electronic computers. This provides me another point of contact with him, since - aside from a brief flirtation with the IBM 650, a boringly easy computer to program - my initial years as a programmer were spent trying to cope with the English Electric DEUCE computer. This computer was a direct descendant of the machine that Turing designed at NPL in the early years after the war. Thanks to Turing’s design, DEUCE was typically much faster in operation than its rivals, albeit almost entirely at the expense of its programmers. Such was the innocence of youth that I and my colleagues actually enjoyed its intricacies, and the problem of finding ways of automating, at least partially, the programming task. Indeed, we felt that contemporary American computer developments, by IBM and others, such as the provision of what seemed to us to be huge memories, and of floating point arithmetic hardware, were in effect cheating. Certainly they were depriving compiler writers such as ourselves of interesting and (we thought) worthwhile challenges.