[fortran77]

The original purpose of most computer programmers was to write a program that would solve an immediate technical problem or a business requirement. The programmer was not concerned with the "technical" (though still important) question: What architecture is this CPU going to use? The first time a programmer encountered the question, his reaction was to try to compile a program that would run on the CPU.

I used to think of this process as a sort of reverse engineering exercise. To figure out what a CPU was doing, you needed to understand the architecture of the CPUs used by the people who were designing it. It was as though you were trying to reverse engineer a car engine using a hand-held computer; to understand how the engine worked you needed to understand how the car engine.