This is the instructor's manual for "An Assembly Language Introduction to Computer Architecture: Using the Intel Pentium", a course for undergraduates in computer organization, assembly language programming, and computer architecture. It introduces students to the fundamentals of computer architecture from a programmer's perspective by teaching them assembly language, the interface between hardware and software. Designed for students in computer science and engineering who have taken one high-level language programming course, it uses a top-down approach, introducing an abstract (registerless) assembly language first. This approach enables students to build on previous knowledge and allows them to write programs from the beginning of the course. Topics covered include basic computer organization, data representation, data structures, the assembly process, exception handling, and more. Examples are developed using the very popular Intel Pentium architecture; however, the concepts covered are valid with any system.