This guide addresses key programming topics, including character devices, mass storage, memory management and process management. The reference section details each MS-DOS function call and interrupt and the BIOS interrupts. New and expanded material in this edition includes, system functions for all current versions of MS-DOS, ROM BIOS information for fixed disk, EGA, VGA, PC/AT and PS/2, version 4.0 of the Lotus/Intel/Microsoft expanded memory specification, writing "well-behaved" versus "hardware-dependent" applications, and compatibility considerations for OS/2.