IA-32 Intel Architecture Software Developer's Manual

The IA-32 Intel Architecture Software Developer's Manual consists of four volumes. The links provided below will drive you to the respective volumes.             
                

     [1]. Volume1 -- Basic Architecture                           ( Vol1.pdf )
                
    [2] . Volume2A -- Instruction Set Reference A-M    ( Vol2A.pdf )

    [3] . Volume2B --
Instruction Set Reference N-Z     ( Vol2B.pdf )

    [4] . Volume3 -- System Programming Guide          ( Vol3.pdf )



All the above manuals can be found at  http://www.intel.com/design/pentium4/manuals/.