## MMPM/2 Device Driver Reference

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### MCI_AUDIO_CONTROL Field - ulPosition

ulPosition (ULONG) Number of units before the request should be executed. This value is used to specify cue points. Caller requests are executed ulPosition number of units from the beginning of the first Write operation after opening a track. Depending on the DSP code loaded and the current mode of operation, units can be bytes, time, or some other unit of measure. For example, to increase the volume of a track after the first 1,000 milliseconds of data have been written to the adapter, issue an AUDIO_ CHANGE request with ulPosition set to 1000. This example assumes that the track information pointed to by pbRequestInfo has been initialized appropriately, and that MCI_AUDIO_BUFFER.ulPositionType = POS_MSECS.

If a request is made for a position number that has already occurred, it is processed immediately. Requests with a position number of 0 are also processed immediately.