The best-selling first edition of The Undocumented PC revealed hidden programming features of PC hardware that allowed programmers to solve tricky problems and dramatically speed up the execution time of their programs. Thoroughly revised and updated, this new edition contains even more undocumented and hard-to-find information. The Undocumented PC includes comprehensive coverage of Pentium, Pentium Pro, and MMX functions, AMD`s 5(subscript k)86 processor, 5x86 and 6x86 CPUs from Cyrix, the Windows 95 keyboard functions, and more. You will find each major subsystem of the PC explained in detail, followed by extensive reference sections that show and explain both documented and undocumented BIOS functions. Going into a level of detail available nowhere else, The Undocumented PC covers all the major system architectures and is still the only available reference to input/output ports, undocumented CPU instructions, fixed memory areas, and much more.