3.8 Building a Virtual Device

You build and install a virtual device by doing the following:

1.Create the virtual device source files and assemble the sources using MASM5.EXE, the 32-bit flat-model assembler.

2.Create a module definition file (.DEF) and link the object files using LINK386.EXE, the 32-bit flat model linker. By convention, the resulting executable file should have the same filename as the virtual device, but with the filename extension .386.

3.Insert virtual device information into the executable file using ADDHDR.EXE.

4.Create a debugging symbol file for the executable file using MAPSYM32.EXE.

5.Add a device setting to the [386Enh] section of the SYSTEM.INI file, specifying the full path of the virtual device executable file.

Although a virtual device is a dynamic-link library, it is not compatible with other Windows dynamic-link libraries. The LINK386.EXE and ADDHDR.EXE programs create a 32-bit executable file whose format is very different from Windows DLLs. Windows applications cannot load and use virtual devices.