'speakersound.bas  
Sub Sound(ByVal freq As UInteger, dur As UInteger)
   Dim t As Double,f1 As Unsigned Short
     f1 = 1193181 \ freq
     Out &h61,Inp(&h61) Or 3
     Out &h43,&hb6
     Out &h42,LoByte(f1)
     Out &h42,HiByte(f1)
     t=Timer  
     While ((Timer - t) * 1000) < dur
       Sleep 0,1
     Wend
     Out &h61,Inp(&h61) And &hfc
End Sub

Sound(523, 60)  'C5
Sound(587, 60)  'D5
Sound(659, 60)  'E5
Sound(698, 60)  'F5
Sound(784, 60)  'G5
Sound(880, 60)  'A5
Sound(988, 60)  'B5
Sound(1046, 60) 'C6