Int 2F Fn 3901  - Kingswood Tsr Windows - Sound Beeper                     [r]

   AX = 3901h
   BL = 0Ah
   DX = sound divisor, or 0 for silence.
        (divide 1843200 by required frequency to get value for DX)
   CL = sound length in 18.2 Hz clock ticks

Return: AX = error code (0000h if successful)
   SI,DI,DS,ES preserved

See Also: AH=39h/BL=00h