In order to succeed at low-level program problem diagnosis, one must have several skills. None of these is particularly difficult, but many are foreign to today's programmers.
At first, it will appear that each problem is solved with a different technique. Study of the methods used to solve problems yields the fact that the several skills are used as appropriate, virtually as subroutines, and without thought, by experienced analysts.
The intent of this material is to provide the basic knowlege and to illustrate each of the skills separately, to aid understanding. Trying to solve problems without the basic skills can be extremely frustrating, at best.
The fundamentals include knowlege of hardware operation, software conventions, and basic use of tools to display the data sought. Once the fundamentals are understood, it is time to begin using them to solve problems, because one can then concentrate on building the problem solving skill.
Application traps are perhaps the easiest problems to approach, so they are explained after the basic skills. Similarly, traps in privileged code are only incrementally more difficult.
Once some experience in solving traps has been gained, it is reasonable to extend one's skills by exploring reasons for waits and loops, collectively known as hangs, or to learn the additional functions provided by Symmetric Multi-Processor (SMP) systems, as well as the challenges in properly serializing them when needed.