BIOS / Int / Int 15 / 10/19


                    INT 15 - TopView - "SOUND" - MAKE TONE

Input			Output
AX	10h	19h		AX
BX	Frequency in Hertz			BX
CX	Duration in Clock Ticks			CX
DX				DX
ES:DI				ES:DI

Note:   If another tone  is  already playing, the new tone does
        not start until completion of  the previous one.  In DV
        2.00, it is  possible  to enqueue about 32 tones before
        the process is blocked  until  a  note completes. in DV
        2.00, the lowest tone allowed is 20 Hz