Hopefully by now you are sufficiently impressed with the complexity of a computer, at least the CPU, which is the heart of the computer. I/O devices and buses are another matter entirely, and are full of their own Byzantine layer upon layer of complexity. However, computer hardware designers have striven to reduce the complexity to manageable levels by employing regularity at every turn. Mathematics also helps a great deal. For instance, DFAs are a purely mathematical construct that can be applied to many real-world situations, including design of the control unit.

In chapter 9 we will look at small programs written in CSC-1's assembler language just to get a feel for how real programs are put together from these incredible minuscule and simple-minded instructions.