The purpose of this book is to give the reader a better understanding of how computers really work at a lower level than in programming languages like Pascal. The tutorial has extensive coverage of interfacing assembly and C code and so might be of interest to C programmers who want to learn about how C works under the hood. All the examples use the free NASM (Netwide) assembler. The tutorial only covers programming under 32-bit protected mode and requires a 32-bit protected mode compiler..