OS/2 Version 2.0, Volume 2: DOS and Windows Environment

This document provides an understanding of the architecture and function of the Multiple Virtual DOS Machines (MVDM) component of OS/2 Version 2.0, which allows concurrent execution of multiple DOS applications, each in its own virtual DOS machine. Further, this document describes the support for Windows applications under OS/2 Version 2.0.

This document contains information on the MVDM architecture and components, including the use of device drivers by DOS applications, and support for expanded and extended memory. Other MVDM-related topics discussed in this document include the DOS Settings feature, which allows the user to determine the way in which a DOS application runs and the resources available to it, and Virtual Machine Boot, which allows the user to load any version of DOS into a virtual DOS machine to support the execution of version-dependent DOS applications.

Support for Windows applications on the OS/2 Version 2.0 platform is another important topic examined in this document. The document includes a discussion of Windows device drivers, inter-process communication between Windows, DOS, and OS/2 applications (including DDE and clipboard capabilities), and compatibility issues as they relate to Windows applications in the OS/2 Version 2.0 environment.

This document is intended for:

• Customer planners and technical support personnel who require an understanding of DOS and Windows implementation in OS/2 Version 2.0.
• IBM and IBM authorized dealer technical support personnel.
• Programmers of DOS and Windows applications who wish to ensure compatibility of their applications with the OS/2 Version 2.0 platform.

The information contained in this document assumes that readers have a general familiarity with the DOS and Windows environments and the applications
which run in these environments.