A stand-alone text for 8051-based courses on Microcontrollers or Industrial Controls. Using a clear writing style and a “nuts and bolts” approach, this text describes the entire field of embedded controllers — hardware, software, and interfacing — using the Intel 8051 microcontroller as an example. The emphasis throughout is on interfacing the 8051 to real-world devices such as switches, displays, motors, A/D converters, etc. — through both assembly language and C language programming.