To write a waveform output driver, first create the initialization part of the driver—the part that includes the LibEntry, WEP, and DriverProc entry-point functions. Next, create the wodMessage entry-point function and the rest of the support code required to implement the driver. Be sure to process all of the required messages for waveform output device drivers. For each message you process, use the information provided in the reference at the end of this chapter to ensure you did everything required to correctly process the message.
Note:
If your waveform device driver makes use of the auto-initialize mode of the DMA controller, you might have to use a VxD called VADMAD.386 to use your device driver with Windows 3.0. For Windows 3.1, this VxD is not required if your device driver uses this mode. For code to detect the Windows version see the source code for the example Sound Blaster device driver.