So, this chapter is a "Newbie Introduction to Computer Architecture" -- our students coming into this course have had computer programming courses and a digital logic course, but they do not know much about computer architecture. They do not know about instructions, machine code, memory, fetch/execute cycle etc. This chapter shows them how to build a very simple "computer' that has memory, fetches/executes instructions etc. This way, they are familiar with these concepts before the next chapter that introduces the PIC24 instructions/architecture.
If a reader is already familiar with these concepts, then this chapter can be skipped. For our students, it serves as a useful bridge from the digital logic course to this course. This shows them how to use their digital logic skills to build this simple 'computer'.