Until now, programming in the low-level Assembler language has been the preserve of a narrow circle of professionals. For the first time, the reader is offered a tutorial that contributes to the formation of fundamental knowledge of the architecture of the Intel Pentium processor and the basics of low-level programming in the Assembler language, which does not require any initial training, except for a certain experience with a personal computer. The publication is intended for specialists in the field of computer science, programmers and users interested in the subject. Written by a professional teacher, the book can be recommended as a teaching aid for university students.