Como tocar sons no auto-falante interno do pc?

Unit Sounds;

interface

uses SysUtils, Windows, Classes, StdCtrls;

procedure Sound(Freq : Word);

implementation

procedure SetPort(address, Value:Word);
var
bValue: byte;
begin
bValue := trunc(Value and 255);
asm
mov dx, address
mov al, bValue
out dx, al
end;
end;

function GetPort(address:word):word;
var
bValue: byte;
begin
asm
mov dx, address
in al, dx
mov bValue, al
end;
GetPort := bValue;
end;

procedure Sound(Freq : Word);
var
B : Byte;
Value: Word;
begin
if Freq > 18 then
begin
Freq := Word(1193181 div LongInt(Freq));
B := Byte(GetPort($61));
if (B and 3) = 0 then
begin
SetPort($61, Word(B or 3));
SetPort($43, $B6);
end;
SetPort($42, Freq);
SetPort($42, Freq shr 8);
end
else
begin
Value := GetPort($61) and $FC;
SetPort($61, Value);
end;
end;
end.