What do Windows 3.1, Lotus 1-2-3, Borland C++, AutoCAD, and FoxPro all have in common? All make use of special operating systems called DOS extenders to transcend the memory limitations of DOS. DOS can address only one megabyte of memory; DOS extenders "extend" the memory limitations so programs can use up to 4,096 megabytes of memory. DOS and Windows Protected Mode is the definitive guide to writing applications that take full advantage of the most popular DOS extenders such as Phar Lap and Intel. It is meticulously detailed with practical source code. The book is divided into three sections that give the critical details on extender technology: *Section one is an introduction to the world of DOS extenders, including discussion of what an extender is, why you'd use one, and which ones are available. *Section two contains many programming examples and focuses on the technical aspects of DOS extenders, including protected-mode pointers, interrupt handling, DPMI calls, and virtual memory.* Section three analyzes fully-functional extender programs including a disk duplication program, a graphics program, and a server that enables DOS and Windows programs to communicate with each other. 0201632187B04062001