replacebits

function replacebits(

  const new: Byte;

  const old: Byte;

  const mask: Byte

):Byte; overload;

function replacebits(

  const new: Word;

  const old: Word;

  const mask: Word

):Word; overload;

function replacebits(

  const new: LongWord;

  const old: LongWord;

  const mask: LongWord

):LongWord; overload;