freepascal.compiler/docs/go32ex/outport.pas

{ This example demonstrates the use of the outport functions.

It simply turns the PC's internal speaker on for 50 ms and off again
}
uses
	crt,
	go32;

begin
	{ turn on speaker }
	outportb($61, $ff);
	{ wait a little bit }
	delay(50);
	{ turn it off again }
	outportb($61, $0);
end.