# MCS® 51 Microcontroller Family User's Manual
The MCS® 51 Microcontroller Family User's Manual is an excellent tutorial for beginners and a valuable reference manual for experienced developers. It contains: A general description of the Intel MCS-51 architecture The complete MCS-51 core instruction set reference Specifications of some popular 8051 derivatives A must for all 8051 newbies!!! It is available for free from Intel Corporation in Adobe Acrobat format. (15 MB) Note: You will need the latest Acrobat Reader from Adobe Systems Inc.! (9 MB)