They actually call it "Hardware." If you look on the left of the thread linked website, you'll see a very nice "Table of contents." In this table of contents, it lists all the topics that the books covers.

HARDWARE

1 Boolean Logic 9

2 Boolean Arithmetic 31

3 Memory 45

4 Machine Language 61

5 Computer Architecture 83

6 Assembler 103

These topics are fundamental to computer science. Boolean algebra is fundamental to computer science. Just because E.E. or C.E. degree courses mention a topic, doesn't mean that topic all of a sudden becomes exclusive to them.

Also, I notice you're using the first edition. May I suggest you look at the second edition, as stated in the title?