In July 1951, Strachey had a chance to visit Manchester and discuss his checkers program with Turing in person. Suitably impressed, Turing suggested that, as a first step, he write a program that would enable the Ferranti Mark I to simulate itself. A simulator would allow programmers to see, step by step, how the computer would execute a program. Such a ‘trace’ program would highlight places where the program caused bottlenecks or ran inefficiently. At a time when both computer memory and processor cycles cost a fortune, this was an important aspect of programming.
The origins of CThat’s kinda mind blowing.