INT 7F U - Voyetra - VAPISG - API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running.  Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes.
	AX = 5658h ('VX')
	BH = C1h
	BL = function (00h-1Bh)
	???
Return: ???
Program: VAPISG is a MIDI(Musical Instrument Digital Interface) A standardized interface for controlling musical instruments with a computer. driver by Voyetra for the Aztech Sound Galaxy
	  sound board
SeeAlso: AX=4331h,AX=564Dh