SAMPLE: VxD Helps MS-DOS Application Query Screen StateLast reviewed: February 15, 1996Article ID: Q67590 |
The information in this article applies to:
SUMMARYThe enhanced mode Microsoft Windows environment does not provide any facility through which an MS-DOS (non-Windows) application can determine whether it is running in a window or full screen. VWFD is a file in the Microsoft Software Library that contains a virtual device (VxD) that provides this information and a sample MS-DOS application that uses the VxD services.
MORE INFORMATIONVWFD is the virtual windowed/full-screen device. When installed on a system running Microsoft Windows in enhanced mode, VWFD allows MS-DOS applications to determine whether they are running full screen or in a window. VWFD supplies the following callback to accomplish this:
call: VWFD_API_Callback entry: BX=VMID of the virtual machine (VM) to test exit: AX=0 if VM is full screenVWFD uses the following virtual machine manager (VMM) services:
You will need Microsoft Macro Assembler version 6.0 or higher, as well as some special tools and include files; see the "VxD Tools" and "VxD Include Files" abstracts to copy these files to your development system. Configure your development environment as described in the "VxD-Lite Mini-DDK" technical article on the Microsoft Developer Network CD. If you have the Windows version 3.1 Device Driver Kit (DDK), you can build its version of VWFD using the DDK-supplied MASM5.EXE (a special version of Macro Assembler version 5.10). Note that the DDK samples require a specific structure for the source and include subdirectories, whereas the corresponding samples in the "VxD-Lite Mini-DDK" utilize the INCLUDE environment variable to give you more flexibility in structuring your development files. To execute VWFD:
Download VWFD.EXE, a self-extracting file, from the Microsoft Software Library (MSL) on the following services: |
Additional reference words: 3.00 3.10 DDKVXD detect softlib VWFD.EXE
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