Author: William Gerbert

Beep/Sound in Delphi

Answer:

The following assembler Routines implement sound output via port access and work 
therefore only with Win3.x and Win95/98. Simply call Sound(hz) with hz as frequency 
in Hz, and stop the sound output with NoSound().

If your application will run under Windows NT, you may use the operating system 
routine:

1   Windows.Beep(Frequency, Duration);
2   
3   
4   function InPort(PortAddr: word): byte; assembler; stdcall;
5   asm
6     mov dx,PortAddr
7     in al,dx
8   end;
9   
10  procedure OutPort(PortAddr: word; Databyte: byte); assembler; stdcall;
11  asm
12    mov al,Databyte
13    mov dx,PortAddr
14    out dx,al
15  end;
16  
17  procedure Sound(Hz: Word);
18  var
19    TmpW: Word;
20  begin
21    OutPort($43, 182);
22    TmpW := InPort($61);
23    OutPort($61, TmpW or 3);
24    OutPort($42, lo(1193180 div hz));
25    OutPort($42, hi(1193180 div hz));
26  end;
27  
28  procedure NoSound;
29  var
30    TmpW: Word;
31  begin
32    OutPort($43, 182);
33    TmpW := InPort($61);
34    OutPort($61, TmpW and 3);
35  end;