type
  IntNo = record
  Low32, Hi32: DWORD;
  end;
 function Multiply(p, q: DWORD): IntNo;
 var
  x: IntNo;
 begin
  asm
  MOV EAX,[p]
  MUL [q]
  MOV [x.Low32],EAX
  MOV [x.Hi32],EDX
  end;
  Result := x
 end;

 // Test the above with:
// So kannst du es testen
var
  r: IntNo;
 begin
  r := Multiply(40000000, 80000000);
  ShowMessage(IntToStr(r.Hi32) + ', ' + IntToStr(r.low32))
 end;