Miles Sound System SDK 7.2a

DDK Function: 400H Get/Set Digital Hardware Volume

Discussion

Input:

AX = 400H
BX = Driver number
DX = 0-127: Set digitized sound volume level 0-127
DX = -1: Read and return current digitized sound volume

Output:

If setting hardware volume

AX = 0-127: Digitized sound volume 0-127 successfully set
AX = -1: Hardware volume control not available

If reading hardware volume

AX = 0-127: Current digitized sound volume level 0-127
AX = -1: Hardware volume control not available

The purpose of this function is to allow applications to calibrate the volume balance between MIDI music and digital sound effects. Its use is optional; no other driver function should alter hardware volume settings (except functions 305H and 306H, if desired).

IMPORTANT: To eliminate the possibility of speaker and/or hearing damage, under no circumstances should any driver alter the device's master volume setting! Master volume settings should be considered the domain of "control panel" utilities -- not individual third-party applications. If a device supports master volume control without a separate facility for digital audio volume, this function should return with AX = -1.

As a courtesy to users, it is recommended that the initialization and shutdown functions (305H and 306H, respectively) save and restore the hardware volume setting.

Group: DOS Digital Sound Driver Interface