DLX is a selective amalgam of several sophisticated load/store architectures; it was developed to serve as a simple example of a pure RISC architecture and is invoked throughout Computer Architecture to demonstrate design principles. With its complete and up-to-date information on the details of DLX, this handbook is a valuable supplement for anyone studying from Computer Architecture, whether self-taught or as part of a class. It will also make an informative addition to the library of any computer systems designer or RISC aficionado. Beginning with the origins and history of DLX, the opening section of the handbook covers the essential topics of registers, data formats, addressing, and interrupt handling. The second section provides a general description of the instruction set architecture, followed by the specifics of DLX instruction types, format notation, and operation notation. Appendices provide a quick reference to the instruction set and the latest available version of documentation for the DLXsim simulator.