Question and Answer Database
FAQ2007C.txt Creating different frequency sounds from win95 / winnt
Category :Windows API
Platform :All
Product :C++Builder 1.x
Question:
I want to be able to make the system beeper make pitched sounds
from my windows application, this needs to work in both windows
NT and 95. How can this be accomplished?
Answer:
In WindowsNT is is easy, use the Beep() Windows API call, however
in Windows 95 this api function is only a little less than useful,
you will need to directly access the hardware. this is demonstrated
in the following code:
The first parameter is the frequency (in Hertz) of the pitch, the
second is the duration in milliseconds of the sound.
The first part of this function sets the pit and turns the speaker
on, the second part (after the Windows API Sleep() call) turns the
speaker off.
This code WILL NOT work in Winnt, so you must use the Beep() API
call for that.
//---------------------------------------------------------------------------
void BeepSound(unsigned short pitch, int duration)
\{
asm mov bx, pitch
asm mov ax, 34DDh
asm mov dx, 0012h
asm cmp dx, bx
asm jnb stop
asm div bx
asm mov bx, ax
asm in al, 61h
asm test al, 3
asm jne j1
asm or al, 3
asm out 61h, al
asm mov al, 0B6h
asm out 43h, al
j1:
asm mov al, bl
asm out 42h, al
asm mov al, bh
asm out 42h, al
stop: ;
Sleep(duration);
asm in al,61H
asm and al, 0fcH
asm out 61H, al
\}
//---------------------------------------------------------------------------
7/2/98 10:32:32 AM
Last Modified: 30-MAR-00