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 = 4331h ('C1') BH = C1h BL = function (00h-7Ah) ??? 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=4150h,AX=564Dh,AX=5658h