Links

Because the links change every so often, Google search links are sometimes used instead.

Processor Manuals

Official Intel manuals

For long time, Intel offers download of its x86 architecture manuals for free, called Software Developer Manuals. The most important are Instruction Set Reference manuals and Basic Architecture manual.

Google search: Intel Software Developer Manuals

Official AMD manuals

AMD offers download of its x86 architecture manuals for free as well as Intel, called Programmer's Manual. Application Programming manual serves as Intel's Basic Architecture manual. General-Purpose and System Instructions serves as Intel's Instruction Set Reference manuals.

Follow the link and then search for "Programmer's Manual" on the page.

Google search: AMD Architecture Programmer's Manual

Official ARM manuals

ARM manuals are free too. Login (free) is required.

ARM Architecture Reference Manuals

File formats

Official PE/COFF specification

Available in DOCX format.

Google search: Microsoft Portable Executable and Common Object File Format Specification

ELF specification

System V Application Binary Interface

Unofficial resources

Sandpile.org

The world's leading source for pure technical x86 processor information.

http://www.sandpile.org

Friends

PELock Software Protection & Software License Key System